I wished that I viewed this when I first got it. The plumber said to keep it on "auto". Like you mentioned most people do not live such a regimented life. Auto did not work for me. I thought "auto" was the only options. I found you and now I am going to try it on "temperature" mode. Hopefully, I will be happy with it now. You explained it very well. Thank you
Great explanation! We moved into a house and had no idea what this was on our hot water heater and could not find a manual online. This video answered all our questions. Thank you for the easy explanations!
Great explanation! We just installed a new water heater and installed the 3 mode version of your pump. The manual gives a pretty basic explanation but I really appreciate your detailed explanation and your recommendations.
Great video - thanks Mark. My question is:- how do we disable the Grundfos system during an electrical power failure? We recently had an electrical power outage (for 3 very long days) and even though we have a gas hot water service, we could not get any hot water because the Grundfos system was unable to work (because there was no electricity). By the way, we have had our Grundfos system for 11 years & we love it. It is very effective, very reliable, we cannot hear the pump at all.
is the 14-day "learn mode" a single, one-and-done process that happens the first time the unit is turned on or is it a sliding window that is constantly learning? In a new build, the builder will test the unit to be sure it works. If that builder uses the only single, one-and-done 14-day learning period, then nothing the owner does after he moves in will change when the unit turns on or off. If the 14-day learning period is an ongoing, sliding window, then the homeowner's habits, not the builder's testing, will govern when the unit turns on/off. Please clarify because none of the documentation on the Grundfos website answers my question.
Thank you for sharing this information. I have a Laing pump on my system that has gone bad and was told that the Grundfos pump might fit directly into the Laing body. Do you know if that is the case or will I have to cut out my Laing and reinstall the new system??
Hi, thanks for the video and the explanation. LEt me ask. Why should i use an expansion thank on the return line if it goes into the cold water side, and why is better to mount the return line into the drain valve of the tank? that`s what i understood. is that correct? thanks
Great. The only thing I didn't get was sizing the pump correctly for the square footage of the house. My house is 4000 sq. ft.. Do I need a different model. Thanks,
I was wondering where to order the union with the larger body to accommodate the check valve. S Is the 98420224 the larger union for check valve? Several of the GRUNDFOS have been discontinued. I could only find the 98420223.
Hello. I have the UP 10-16 Auto pump which replaced the one that always stays on due to make a loud buzzing noise after 2 years. I had a plumber replace it but after 48hrs the new one is making the same noise when it runs on the auto feature. Do you have any recommendations or suggestion of what the issue can be?
A plumber just replaced my grundfos pump,. We had the one that had a plastic cap that covered the timer switches, we didn't use the timer at all. They put the second pump you show in this video and the hot water take like 5 to 10 minutes to start up. I tried it at 100% as well. Any ideas we have that furnace type tankless water heater
Mark Thank you for a great video. Our house was built in 87 and it takes long time to get hot water in the shower. We also have a water softener. I heard that to install a recirculating pump you have to do something to the softener. Can you let me know what that is? Thanks in advance
Your video is awesomely informative. I really like it. But, I have one question... Will these units work with Tankless water heaters? I have the Rinnai RU199iN (not the RUR series) and I want to install a dedicated return recirculation system. Thanks for the great video. Cheers!
The only way to use a hot water recir line with a tankless is to use a small tank in a return line and use the UP10-16 through that tank and not the tankless. Most of the time people will use one of those instant hot water heaters that people put under their kitchen sinks. This way if the UP10-16 needs to run because the line is getting to cold the little instant hot water tank will heat up and provide hot water without turning on the Rinnai.
@@markkrumnow8203 My plumber installed the "cadillac" model for me. I do have a Rinnai R94LS. Are you saying that without an additional smaller 1 gallon tank as part of the system, The Grundfos should not be part of my system? I went through two 1-gallon tanks which burnt out because of the extremely hard water that we have in our city.
My hot water recirculation system's electricity costs zero to run per year. If you have a return line from far end - look into using a gravity system. Zero maintenance and works great!
I moved into a house that is 16 years old. It has a UP10-16BN5/LC. Other than how quick the water gets hot at the faucet, how do I know this unit is still working/running. Thanks.
Hi Mark, great concise explanation... just what I was looking for... I need to run the return line back and want to know if I should go with 1/2 or 3/4 pex. any preference? basically seems to come down to high volume with 3/4...
Most of the time for people with a 3,000 square foot house or smaller they use a 1/2" pass that it would not hurt to use a 3/4" return line. Hopefully that helps.
@@markkrumnow8203 so can the return to the pump be smaller, if I have a 3/4" PEX loop to all the fixtures can I transition to 1/2" back to the pump? I can't see what not, I don't care if the circulation pump has low flow since it just runs in the background.
@@bluearcherx Yes, most return lines are 1/2", depending on the size of the house. As long as water is being returned, then the GPM and head pressure is adequate.
I have a Grundfos with the three settings ,hooked up to a Honeywell two wire thermostat (This unit is for heated floors)if i disconnect the thermostat the unit works , how do i control temperature
I've had issues w/ my comfort 10-16 from day 1 in temp control mode (Not auto adapt). I have the Tsupply sensor on the DHW outlet about 10" from the tank and the return Treturn is integral to the pump obviously. Tsupply is 95F (Should be at least as it's based on my IR temp gun) and Treturn is near ambient at 74F. So either the Tsupply or Treturn sensors are bad I feel The pump is ALWAYS in standby except for initial power up. Ever seen this? I am having a hard time getting ahold of anyone at grungdfos.
If i want to use this circulation pump with glasstub type solar water heater 100 litter capacity, lower level than main tank, what type of back flow preventer to be installed to protect glass tube washer leaksge, except NRV?
Question: I've got two separate circuits, one for the left side of the house, the other for the right side of the house, each with their own return line. If I installed a single pump at the drain on the bottom of the hot water tank, might I have problem with it pulling more from one side compared to the other, so that the users on one side of the house will have hot water, but the users on the other side won't? Also, I imagine that each circuit would need its own check valve so that one side doesn't pull from the other.
I am a plumber and I just did a renovation in a house similar to yours. I had to run 2 separate return lines with 2 separate recirc pumps. I used the 3rd one he showed
What is the reason you don't need an expansion tank when the hot water return line enters the water heater at the bottom (where drain valve is) as opposed to needing to have one when the return line enters at the cold inlet on top of the tank?
How much more expensive will your utility bill be? Whether your water is heated by gas or electricity, a recirculating pump will cause a drop in the temperature of the water in the water heater tank causing the tank to turn on to heat the entire tank.
it will go back to the setting that you last had it on, so if you have it on 100% and the power goes out, then it will come back on at 100%. this is how i control the pump with a cheap digital timer because the sensors dont do CRAP.
@@morejelloplease thanks for the reply! I've heard other things about the sensors not working well. Might just get the cheaper, always on version and hook it up to a smart switch
The UP10-16 pump in temperature mode relies on the internal sensor in the pump to control when it turns on or off. Most of the time when it is not responding correctly a check valve was not put on the return line. You can use the temperature mode and a timer if that works for you.
i've had one of these auto adapt units installed for 3 years now, I have the sensor in the correct location and i'm trying temp mode. it was decent for the first few days, it's been 2 weeks now and i have cold water literally all the time, the silly light just flashes. its like there's no pump at all. the sensor is clean and attached direct to the copper outlet nice and tight. any ideas why it's not working? grundfos is impossible to get a hold of, i would recommend a regular 100% on pump and control it with a digital timer. luckily this is what i've been doing to get by, however this pump was NOT cheap and it doesn't do what it's supposed to do, unless i'm missing something. the pump is installed correctly on the return just before it enters the bottom of the tank. theres also an expansion tank installed. the return is in the slab and there's a 10 degree temp drop once it makes a loop thru the entire house. i'm at wits end trying to get hot water at my kitchen faucet which is the last stop before it returns to the tank. there's also a sweet spot cycling on and off to what i call keeping the lines "primed" not only will it get hotter faster since you're not wasting time and energy re-heating the PEX in the foundation, the water temp going back into the bottom of the water heater is warmer so the water heater runs less. add a rheem hybrid 80gal into the mix in a single story 3300 sq ft house and you see my problem. if you have any suggestions or want to yack about this over the phone i'm all ears.
no, i'm trying to find detailed info on this but it's hard. i'd like to see what the algorithm is for how it determines when to cycle the pump, how it senses movement and compares the temp between the two sensors. i had it on temp mode for 2 weeks, i had hot water for a few days then it was cold. i just reset it and now trying auto adapt mode and it turns on whenever it wants.
The pump model is a UP10-16 Temperature only with union fittings. As a reminder when you purchase this pump, you also have to purchase the mating fittings.
@@markkrumnow8203 Mark I hate to sound dumb, but I don't see the fitting I need on ur wed. I bought the UP10-16 Temperature only with union fittings. I (think) I need half union female with 3/4 NPT male; two pcs. Can you send me a link where I can purchase the fittings I need??
Doesn’t Running it too often cause your gas bill to skyrocket since you are now putting a demand on the water tank to constantly keep the water hot? I just moved into a house that has this pump and without the pump the water is lukewarm to cold so I use the pump but scared of running it too often and getting a massive gas bill
this topic is a fine line, and varies depending on the install. in my situation there's no free lunch. i was trying to run the pump as less as possible but found out that this actually hurt the system because once it primed the lines it would shut off, the lines then cool and the sitting water was fed back into the water heater and then the heater cycled more. short story long, i had to run the pump longer and prime the lines more to retain more heat so that when the heater saw the water come back in, it wasn't cold enough to turn on the heater. i'd rather have a 7watt pump run for an extra 10 minutes than a 500w heat pump or 5kW element. if you really want to split hairs, then use a whole house energy monitor to break down your exact power consumption, but at the end of the day it's piece of mind to turn on a hot water faucet and get hot water in seconds. right now i'm fighting this stupid grundfos auto adapt pump with sensors that has a mind of it's own. when this pump dies i'll buy a cheap 100% pump and control it with a cheap digital timer or wifi switch with custom on/off times. hope this helps, i've been fighting this for 2 years now, brand new house, new pump, new everything. looks like i'll have to accept "good enough" for an answer in my situation because no one has found a solution yet.
The sole purpose of a hot water recir line is so that when you turn on your fixture you have hot water and you are not dumping water that was once heated and is now room temperature down the drain. When the pump senses (return temperature sensor located in the pump) that the water is colder than the supply by approximately 10 degrees the pump light goes solid and moves the room temperature water in your hot water pipes back into your hot water tank to reheat. Your tank is typically a 40 gallon tank with a recovery time off approximately 20 minutes. That would be a complete drain down of your tank. By returning approximately 1 to 2 gallons your hot water tank will only turn on maybe a minute or two.
@@markkrumnow8203 show me where it says there's a 10 degree split from sensor to sensor. i have 120 coming out of the outlet and 88 goign back in. this stupid pump just sits here. the other day it turns on for 30 secs and off for 30 seconds. andis it smart enough to know that when it turns itself on that the water moving thru the pipe is not a tapping incident? whenever i turn on a faucet for 5, seconds or a minute, the pump does nothing, these sensors dont work properly and no one at grundfos can explain it properly, they are ignoring me now. it takes 2 mins 30 secs for the water to make a complete trip out the supply and back thru the return and into the water heater. idle water will cool a degree per minute, so if the pump is off for 10 mins and stays off, then when i turn on a faucet i get 109-111 degree water for the next 2m 30 secs. when the pump sits there and flashes at me then i get luke warm water for 2m 30 seconds, does that make sense?
another thought occurred to me, if the sensor is on the hot output and you turn on a faucet for say 10 seconds, it's going to send a signal to the pump that the temp is met and the pump will never activate, this is the problem i'm running into, which almost confirms the sensor on the ribbon cable needs to be on the return line , i know there's supposed to be another sensor built into the chassis of the unit but i'm getting different results. when you first power up the unit and put it in auto adapt mode, the unit still starts out in temp mode for two weeks, if temp mode uses the internal sensor, then why does the unit turn off and on when heat is applied to the external sensor? these are all questions grundfos usa could NOT answer and simply told me to buy a new pump. GRUNDFOS are you listening?! I never got the benefit of the bargain if you want to call it that, having this $500 pump installed in my newly constructed house 2 years ago and it never worked properly, MAKE IT RIGHT GRUNDFOS!
I am sorry that you are having problems. If you turn on the fixture and you have hot water that should not effect if the pump turns on or not. In the temperature mode the pump is not looking at usage but is comparing the supply temperature to the return temperature. When that occurs the pump turns its light on solid (not flashing) and pulls water through the supply and the return to the pump which at that point in time says hey I must be hot since my return temp is very close to my supply.
@@markkrumnow8203 i get that, but as explained in the other reply the pump is located in the return line right before it enters the tank, the temp difference at any given time is about 20-30 degrees. i measure it with a thermaworks probe at the kitchen faucet which is about 20 feet from the return input, i bet it drops another degree or two before it gets to the pump. so 120-122 out vs 86-90 in. big difference, this pump sensor system sucks. look at all the forums, lots of people complain about these sensors that dont work right.
@@morejelloplease Same deal for me. Tsupply is 95F and Treturn is ambient at 74F. With the external sensor 10" from the DHW outlet the pump is ALWAYS in standby mode except on initial powerup. Even after a 20 minute shower it never leaves standby mode and return water temp at the pump is always near ambient. The sensor clearly isn't working as designed. I'd guess it's the external that is the problem.
so i've been playing with my sensors, grundfos wrote me off and said i have a defective unit and need to buy a new one, it's out of warranty , i've been tryingto contact them since we moved into this new house. anyways long story short i've been playing with thes sensors, turns out the sensor on the ribbon cable is way too sensitive. when i remove it from the hot water line after 30 seconds the pump turns on. when i re-install it on the hot line after about 45 seconds it goes into flashing standby mode again. that tells me that this external sensor should be mounted on the return side of things but it won't recording tapping events in auto mode. that's fine with me, because if it's doing it's job keeping the lines primed with hot water whenever i turn the handle then it doesnt need to know my schedule. with covid were all home and need hot water on demand. so that leads us to the temp mode, if this thing was working properly the other temp sensor mounted in the chassis itself would detect when the return water reached temp and shut off but it doesnt. it seems to be satisfied with 80 degree water. so back to the drawing board, i put a few pieces of electrical tape under the sensor to insulate it from the pipe to reduce temps to the sensor, we'll see how that works. i'll keep adding tape until it works correctly. this grundfos is a nightmare!!
back to the drawing board, the unit is now cycling on and off at 30 second intervals and it's putting cooler water into the bottom of the water heater tank which is making the water heater heat pump run non stop now. all that to say this, run a 100% pump and put it on a digital timer that cycles on/off at the intervals that meet your needs, grundfos can goto hell.
@@markkrumnow8203 thanks for taking the time to chime in, i dont want to waste your time, i need to talk to grundfos to find out how their system works exactly. i dont think replacing this pump is going to solve anything, it' sjust the nature of the beast.
Incomplete or purposely omitting description of energy costs! I agree that the cost of running the pump is almost nothing, but it is the cost of unnecessarily re-heating the cooler water returning to the tank that is the game changer. You should use a timer or manual button switch or the auto learn mode.
In no way is the purpose of this to save $ on heating water. It is for A) comfort and B) saves on water waste. If you want to save $ on heating water, do not use a circulator.
@@bigdog8008 No reasonable amount of insulation will keep the hot water in the pipes from shedding significant amounts of heat over time. The reason your hot water tank cycles on even when no hot water is used is because heat is lost through the insulated walls of the tank. Keeping the water in the pipes hot along with the water in the tank will add to that loss even if they are insulated. Also, most people aren't going to tear down walls to insulate their pipes.
Thank you for a straightforward no BS explanation. I'm so tired of videos that put entertainment over information.
I wished that I viewed this when I first got it. The plumber said to keep it on "auto". Like you mentioned most people do not live such a regimented life. Auto did not work for me. I thought "auto" was the only options. I found you and now I am going to try it on "temperature" mode. Hopefully, I will be happy with it now. You explained it very well. Thank you
Great explanation! We moved into a house and had no idea what this was on our hot water heater and could not find a manual online. This video answered all our questions. Thank you for the easy explanations!
I appreciate your instructions regarding
The Grundfos circulating pump, again "Thank you!"
Great explanation! We just installed a new water heater and installed the 3 mode version of your pump. The manual gives a pretty basic explanation but I really appreciate your detailed explanation and your recommendations.
Very informative. Exactly what I was looking for. Thank you!
Great clear explanation. thanks for the video
Great video - thanks Mark.
My question is:- how do we disable the Grundfos system during an electrical power failure? We recently had an electrical power outage (for 3 very long days) and even though we have a gas hot water service, we could not get any hot water because the Grundfos system was unable to work (because there was no electricity).
By the way, we have had our Grundfos system for 11 years & we love it. It is very effective, very reliable, we cannot hear the pump at all.
if your water heater is on you still get hot water unless you have a issue with a check.
is the 14-day "learn mode" a single, one-and-done process that happens the first time the unit is turned on or is it a sliding window that is constantly learning? In a new build, the builder will test the unit to be sure it works. If that builder uses the only single, one-and-done 14-day learning period, then nothing the owner does after he moves in will change when the unit turns on or off. If the 14-day learning period is an ongoing, sliding window, then the homeowner's habits, not the builder's testing, will govern when the unit turns on/off. Please clarify because none of the documentation on the Grundfos website answers my question.
I have the same question. Did you find an answer to this? Thank you.
I watched the entire video and can not order a Grundfos pump, because the model numbers were not mentioned!
Thank you for sharing this information. I have a Laing pump on my system that has gone bad and was told that the Grundfos pump might fit directly into the Laing body. Do you know if that is the case or will I have to cut out my Laing and reinstall the new system??
Hi, thanks for the video and the explanation. LEt me ask. Why should i use an expansion thank on the return line if it goes into the cold water side, and why is better to mount the return line into the drain valve of the tank? that`s what i understood. is that correct? thanks
Hi may I ask what is the model number of the last one that you recommending the most? Thank you
How long does it take for the coldest water to show up?
Great. The only thing I didn't get was sizing the pump correctly for the square footage of the house. My house is 4000 sq. ft.. Do I need a different model. Thanks,
What model # is the 3rd (last) pump that you showed?
I have a multistory house and my furthest sink is about 15’ above the water heater. Can you recommend a pump that can handle that head?
Hello. Will these pumps work on a water heater that has the heat traps on them?? Thanks
I was wondering where to order the union with the larger body to accommodate the check valve. S Is the 98420224 the larger union for check valve? Several of the GRUNDFOS have been discontinued. I could only find the 98420223.
Is that last one you demonstrated okay to use on a tankless? Rinnai RUC 80
thank u
Hello. I have the UP 10-16 Auto pump which replaced the one that always stays on due to make a loud buzzing noise after 2 years. I had a plumber replace it but after 48hrs the new one is making the same noise when it runs on the auto feature. Do you have any recommendations or suggestion of what the issue can be?
A plumber just replaced my grundfos pump,. We had the one that had a plastic cap that covered the timer switches, we didn't use the timer at all. They put the second pump you show in this video and the hot water take like 5 to 10 minutes to start up. I tried it at 100% as well. Any ideas we have that furnace type tankless water heater
where can I find the 1 1/4 matting union in 3/4 npt? I do not find it on your web site...
What problems are created if the water heater is kept at a tightest temperature?
Mark Thank you for a great video. Our house was built in 87 and it takes long time to get hot water in the shower. We also have a water softener. I heard that to install a recirculating pump you have to do something to the softener. Can you let me know what that is? Thanks in advance
Do you have a non-timer pump recommendation for a tankless system?
Your video is awesomely informative. I really like it. But, I have one question... Will these units work with Tankless water heaters? I have the Rinnai RU199iN (not the RUR series) and I want to install a dedicated return recirculation system. Thanks for the great video. Cheers!
The only way to use a hot water recir line with a tankless is to use a small tank in a return line and use the UP10-16 through that tank and not the tankless. Most of the time people will use one of those instant hot water heaters that people put under their kitchen sinks. This way if the UP10-16 needs to run because the line is getting to cold the little instant hot water tank will heat up and provide hot water without turning on the Rinnai.
@@markkrumnow8203 My plumber installed the "cadillac" model for me. I do have a Rinnai R94LS. Are you saying that without an additional smaller 1 gallon tank as part of the system, The Grundfos should not be part of my system? I went through two 1-gallon tanks which burnt out because of the extremely hard water that we have in our city.
Can the always on pump be used as a de stratification pump
My hot water recirculation system's electricity costs zero to run per year. If you have a return line from far end - look into using a gravity system. Zero maintenance and works great!
would this work with a Navien NPE 240S tankless hot water heater?
If you don’t want hot water circulating thru uninsulated water pipes can you just unplug an always on recirculating pump?
Will this work well for a 24 unit apartment complex?
I moved into a house that is 16 years old. It has a UP10-16BN5/LC. Other than how quick the water gets hot at the faucet, how do I know this unit is still working/running. Thanks.
I need to pick the right one for a tankless.
If the water is on a private well is this going to ruin the pump?
Hi Mark, great concise explanation... just what I was looking for... I need to run the return line back and want to know if I should go with 1/2 or 3/4 pex. any preference? basically seems to come down to high volume with 3/4...
Most of the time for people with a 3,000 square foot house or smaller they use a 1/2" pass that it would not hurt to use a 3/4" return line. Hopefully that helps.
@@markkrumnow8203 so can the return to the pump be smaller, if I have a 3/4" PEX loop to all the fixtures can I transition to 1/2" back to the pump? I can't see what not, I don't care if the circulation pump has low flow since it just runs in the background.
@@bluearcherx Yes, most return lines are 1/2", depending on the size of the house. As long as water is being returned, then the GPM and head pressure is adequate.
I have the unit with the temperature sensor. Can I install the pump under the farthest sink?
Where we can buy that product in Canada?
I have a Grundfos with the three settings ,hooked up to a Honeywell two wire thermostat (This unit is for heated floors)if i disconnect the thermostat the unit works , how do i control temperature
for those with tankless water heater would needed one of these to avoid the "cold water sandwich" issues
I've had issues w/ my comfort 10-16 from day 1 in temp control mode (Not auto adapt). I have the Tsupply sensor on the DHW outlet about 10" from the tank and the return Treturn is integral to the pump obviously. Tsupply is 95F (Should be at least as it's based on my IR temp gun) and Treturn is near ambient at 74F. So either the Tsupply or Treturn sensors are bad I feel The pump is ALWAYS in standby except for initial power up. Ever seen this? I am having a hard time getting ahold of anyone at grungdfos.
If i want to use this circulation pump with glasstub type solar water heater 100 litter capacity, lower level than main tank, what type of back flow preventer to be installed to protect glass tube washer leaksge, except NRV?
where do the rubber washers go on the union sweet
Question: I've got two separate circuits, one for the left side of the house, the other for the right side of the house, each with their own return line. If I installed a single pump at the drain on the bottom of the hot water tank, might I have problem with it pulling more from one side compared to the other, so that the users on one side of the house will have hot water, but the users on the other side won't? Also, I imagine that each circuit would need its own check valve so that one side doesn't pull from the other.
I am a plumber and I just did a renovation in a house similar to yours. I had to run 2 separate return lines with 2 separate recirc pumps. I used the 3rd one he showed
What is the reason you don't need an expansion tank when the hot water return line enters the water heater at the bottom (where drain valve is) as opposed to needing to have one when the return line enters at the cold inlet on top of the tank?
hi have you find out what the explanation was? thank you
can u ran this unit on 230V
How much more expensive will your utility bill be? Whether your water is heated by gas or electricity, a recirculating pump will cause a drop in the temperature of the water in the water heater tank causing the tank to turn on to heat the entire tank.
Has anyone gotten an answer to these questions?
would have been nice for him to tell us complete model numbers of each unit he mentioned.
Wally is correct. I watched the entire video and can not order a Grundfos pump, because the model numbers were not mentioned!
Can you put one of the pumps with the temperature mode on a timer? When it turns back on will it keep its setting?
it will go back to the setting that you last had it on, so if you have it on 100% and the power goes out, then it will come back on at 100%. this is how i control the pump with a cheap digital timer because the sensors dont do CRAP.
@@morejelloplease thanks for the reply! I've heard other things about the sensors not working well. Might just get the cheaper, always on version and hook it up to a smart switch
The UP10-16 pump in temperature mode relies on the internal sensor in the pump to control when it turns on or off. Most of the time when it is not responding correctly a check valve was not put on the return line. You can use the temperature mode and a timer if that works for you.
Can you please send me item/part numbers and their descriptions so nI know what I need to purchase? Thanks
The recirculating pumps are great - until you receive your first gas bill to run the water heater more often.
Huh, I never thought of that one.
How much of difference though?
i've had one of these auto adapt units installed for 3 years now, I have the sensor in the correct location and i'm trying temp mode. it was decent for the first few days, it's been 2 weeks now and i have cold water literally all the time, the silly light just flashes. its like there's no pump at all. the sensor is clean and attached direct to the copper outlet nice and tight. any ideas why it's not working? grundfos is impossible to get a hold of, i would recommend a regular 100% on pump and control it with a digital timer. luckily this is what i've been doing to get by, however this pump was NOT cheap and it doesn't do what it's supposed to do, unless i'm missing something. the pump is installed correctly on the return just before it enters the bottom of the tank. theres also an expansion tank installed. the return is in the slab and there's a 10 degree temp drop once it makes a loop thru the entire house. i'm at wits end trying to get hot water at my kitchen faucet which is the last stop before it returns to the tank. there's also a sweet spot cycling on and off to what i call keeping the lines "primed" not only will it get hotter faster since you're not wasting time and energy re-heating the PEX in the foundation, the water temp going back into the bottom of the water heater is warmer so the water heater runs less. add a rheem hybrid 80gal into the mix in a single story 3300 sq ft house and you see my problem. if you have any suggestions or want to yack about this over the phone i'm all ears.
Did you get an answer to your question?
no, i'm trying to find detailed info on this but it's hard. i'd like to see what the algorithm is for how it determines when to cycle the pump, how it senses movement and compares the temp between the two sensors. i had it on temp mode for 2 weeks, i had hot water for a few days then it was cold. i just reset it and now trying auto adapt mode and it turns on whenever it wants.
And what do you know, all of the status lights on the front are out. I had to press a button to wake it up, now what the heck is this thing doing???
@@morejelloplease do you have an expansion tank on your setup? Wasn’t sure if one was needed or not. I’ve heard some say yes and some say no.
@@jerryz255 I do to protect for water hammer.
what is the modal number of the last pump you showed; where can i purchase it?
The pump model is a UP10-16 Temperature only with union fittings. As a reminder when you purchase this pump, you also have to purchase the mating fittings.
@@markkrumnow8203 Mark I hate to sound dumb, but I don't see the fitting I need on ur wed. I bought the UP10-16 Temperature only with union fittings. I (think) I need half union female with 3/4 NPT male; two pcs. Can you send me a link where I can purchase the fittings I need??
Can you provide model numbers for these three units you are describing?
Same question
Should the setting be turned on to 100%?
That’s what I ended up doing. Figured the cost was so minimal (pay .06/kWh) and the lack of stop/start cycles would extend life of pump.
@@bpdp379 You have amazingly inexpensive electricity, but note that the main cost is in keeping the hot water and recirc pipes hot.
@@mpeg12 sure enough. Everybody has to pay the piper somewhere, right?
can the pump run 24/7?
Yup
Doesn’t Running it too often cause your gas bill to skyrocket since you are now putting a demand on the water tank to constantly keep the water hot? I just moved into a house that has this pump and without the pump the water is lukewarm to cold so I use the pump but scared of running it too often and getting a massive gas bill
this topic is a fine line, and varies depending on the install. in my situation there's no free lunch. i was trying to run the pump as less as possible but found out that this actually hurt the system because once it primed the lines it would shut off, the lines then cool and the sitting water was fed back into the water heater and then the heater cycled more. short story long, i had to run the pump longer and prime the lines more to retain more heat so that when the heater saw the water come back in, it wasn't cold enough to turn on the heater. i'd rather have a 7watt pump run for an extra 10 minutes than a 500w heat pump or 5kW element. if you really want to split hairs, then use a whole house energy monitor to break down your exact power consumption, but at the end of the day it's piece of mind to turn on a hot water faucet and get hot water in seconds. right now i'm fighting this stupid grundfos auto adapt pump with sensors that has a mind of it's own. when this pump dies i'll buy a cheap 100% pump and control it with a cheap digital timer or wifi switch with custom on/off times. hope this helps, i've been fighting this for 2 years now, brand new house, new pump, new everything. looks like i'll have to accept "good enough" for an answer in my situation because no one has found a solution yet.
@@morejelloplease thank you for explaining this
The sole purpose of a hot water recir line is so that when you turn on your fixture you have hot water and you are not dumping water that was once heated and is now room temperature down the drain. When the pump senses (return temperature sensor located in the pump) that the water is colder than the supply by approximately 10 degrees the pump light goes solid and moves the room temperature water in your hot water pipes back into your hot water tank to reheat. Your tank is typically a 40 gallon tank with a recovery time off approximately 20 minutes. That would be a complete drain down of your tank. By returning approximately 1 to 2 gallons your hot water tank will only turn on maybe a minute or two.
@@markkrumnow8203 show me where it says there's a 10 degree split from sensor to sensor. i have 120 coming out of the outlet and 88 goign back in. this stupid pump just sits here. the other day it turns on for 30 secs and off for 30 seconds. andis it smart enough to know that when it turns itself on that the water moving thru the pipe is not a tapping incident? whenever i turn on a faucet for 5, seconds or a minute, the pump does nothing, these sensors dont work properly and no one at grundfos can explain it properly, they are ignoring me now. it takes 2 mins 30 secs for the water to make a complete trip out the supply and back thru the return and into the water heater. idle water will cool a degree per minute, so if the pump is off for 10 mins and stays off, then when i turn on a faucet i get 109-111 degree water for the next 2m 30 secs. when the pump sits there and flashes at me then i get luke warm water for 2m 30 seconds, does that make sense?
@@morejelloplease Please call so we can discuss your system. Please check website for my phone number
another thought occurred to me, if the sensor is on the hot output and you turn on a faucet for say 10 seconds, it's going to send a signal to the pump that the temp is met and the pump will never activate, this is the problem i'm running into, which almost confirms the sensor on the ribbon cable needs to be on the return line , i know there's supposed to be another sensor built into the chassis of the unit but i'm getting different results. when you first power up the unit and put it in auto adapt mode, the unit still starts out in temp mode for two weeks, if temp mode uses the internal sensor, then why does the unit turn off and on when heat is applied to the external sensor? these are all questions grundfos usa could NOT answer and simply told me to buy a new pump. GRUNDFOS are you listening?! I never got the benefit of the bargain if you want to call it that, having this $500 pump installed in my newly constructed house 2 years ago and it never worked properly, MAKE IT RIGHT GRUNDFOS!
I am sorry that you are having problems. If you turn on the fixture and you have hot water that should not effect if the pump turns on or not. In the temperature mode the pump is not looking at usage but is comparing the supply temperature to the return temperature. When that occurs the pump turns its light on solid (not flashing) and pulls water through the supply and the return to the pump which at that point in time says hey I must be hot since my return temp is very close to my supply.
@@markkrumnow8203 i get that, but as explained in the other reply the pump is located in the return line right before it enters the tank, the temp difference at any given time is about 20-30 degrees. i measure it with a thermaworks probe at the kitchen faucet which is about 20 feet from the return input, i bet it drops another degree or two before it gets to the pump. so 120-122 out vs 86-90 in. big difference, this pump sensor system sucks. look at all the forums, lots of people complain about these sensors that dont work right.
@@morejelloplease Isn't the pump supposed to be installed on the outlet side of the water heater?
@@morejelloplease Same deal for me. Tsupply is 95F and Treturn is ambient at 74F. With the external sensor 10" from the DHW outlet the pump is ALWAYS in standby mode except on initial powerup. Even after a 20 minute shower it never leaves standby mode and return water temp at the pump is always near ambient. The sensor clearly isn't working as designed. I'd guess it's the external that is the problem.
so i've been playing with my sensors, grundfos wrote me off and said i have a defective unit and need to buy a new one, it's out of warranty , i've been tryingto contact them since we moved into this new house. anyways long story short i've been playing with thes sensors, turns out the sensor on the ribbon cable is way too sensitive. when i remove it from the hot water line after 30 seconds the pump turns on. when i re-install it on the hot line after about 45 seconds it goes into flashing standby mode again. that tells me that this external sensor should be mounted on the return side of things but it won't recording tapping events in auto mode. that's fine with me, because if it's doing it's job keeping the lines primed with hot water whenever i turn the handle then it doesnt need to know my schedule. with covid were all home and need hot water on demand. so that leads us to the temp mode, if this thing was working properly the other temp sensor mounted in the chassis itself would detect when the return water reached temp and shut off but it doesnt. it seems to be satisfied with 80 degree water. so back to the drawing board, i put a few pieces of electrical tape under the sensor to insulate it from the pipe to reduce temps to the sensor, we'll see how that works. i'll keep adding tape until it works correctly. this grundfos is a nightmare!!
back to the drawing board, the unit is now cycling on and off at 30 second intervals and it's putting cooler water into the bottom of the water heater tank which is making the water heater heat pump run non stop now. all that to say this, run a 100% pump and put it on a digital timer that cycles on/off at the intervals that meet your needs, grundfos can goto hell.
Call our office and I can talk with you directly.
@@markkrumnow8203 thanks for taking the time to chime in, i dont want to waste your time, i need to talk to grundfos to find out how their system works exactly. i dont think replacing this pump is going to solve anything, it' sjust the nature of the beast.
Incomplete or purposely omitting description of energy costs! I agree that the cost of running the pump is almost nothing, but it is the cost of unnecessarily re-heating the cooler water returning to the tank that is the game changer. You should use a timer or manual button switch or the auto learn mode.
Insulate the line.
In no way is the purpose of this to save $ on heating water. It is for A) comfort and B) saves on water waste. If you want to save $ on heating water, do not use a circulator.
Keeping your pipes hot wastes heat even if it saves water.
Handy little product out there called "pipe insulation". Look into that someday.
@@bigdog8008
No reasonable amount of insulation will keep the hot water in the pipes from shedding significant amounts of heat over time. The reason your hot water tank cycles on even when no hot water is used is because heat is lost through the insulated walls of the tank. Keeping the water in the pipes hot along with the water in the tank will add to that loss even if they are insulated.
Also, most people aren't going to tear down walls to insulate their pipes.
@@Andy-df5fj OK -- this works quite well for me but you do your own thing and run your hot water for 20 minutes before getting in the shower.
What is the model of the last pump? Thanks