THE AC IS HEATING AND COOLING AT THE SAME TIME
Vložit
- čas přidán 15. 03. 2023
- An interesting double heat and cooling call
HVACR VIDEOS MERCH WEBSITE - www.hvacrvideos.com
Please consider supporting my channel by
Becoming a Patreon member - Patreon / hvacrvideos
Becoming a CZcams channel member / @hvacrvideos
By purchasing tools via my affiliate links below at TRUTECHTOOLS.COM and use the offer code BIGPICTURE to save 8% on your total purchase (exclusions apply)
Visiting my website and purchasing merch www.hvacrvideos.com
HVAC OVERTIME CHANNEL LINK - / hvacovertime
Social Media
Facebook / hvacr-videos
Instagram / hvacrvideos
For any inquiries please contact me at chris@hvacrvideos.com
Mailing Address
HVACR VIDEOS
12523 LIMONITE AVE.
440 - 184
MIRA LOMA, CA. 91752
The repair was a gem within itself but the insights you gave about dealing with your current situation and not placing yourself in situations you'll regret in the long run was 'PRICELESS'. The ability to recognize pitfalls before you're actually in the midst of one translates into unwasted time and therefore 'smart business'. Thank you for wisdom like this. P.S. I can't move until the end of your videos.
I have mounted several T-stats just like that to keep staff from screwing with it. Sometimes a T-stat is mounted in a crappy location and it's not possible to run new wire and this is preferable. No complaints from me.
This is a prime example why a good systems integrator is worth their weight in gold. An HVAC installer/service can be a great systems integrator if they know their stuff, and often have first hand knowledge of what equipment plays well together and is reliable. The more complicated a system, the more failure points, and some people want features at the expense of reliability. Most customers don't understand all of the technical issues that they are facing with their choices. This leaves them vulnerable to unscrupulous sales pitches, and they may end up with less than optimal, unreliable, or poorly installed systems.
Whenever I have to install a "temporary" fix, I always make sure it is to code and done well, since you never know how long it will be used. Nothing wrong with a T-stat in a duct for such emergencies, it is just a temperature probe connected to a control unit.
There is nothing more permanent than a temporary fix.
This is the best example of a thorough AC diagnostic that I have come across to date. Most AC repair companies refuse to quote or outline tactical issues and jump directly to strategic options that cost more. I appreciate the thoroughness and believe that this approach will always be profitable for anyone in the industry.
I've done that many times and like you said, less problems with those units😂. Honestly, your wire job through the blower compartment is a better job than how Carrier did it! My only stipulation is to write that you did this on the electrical panel cover
Re: mouse chewing cable and weird stuff.
I work in IT and we once had an *armored* fiber optic cable get chewed through by a beaver. It of course happened in the middle of the woods between sites and the fiber was at the bottom of a pond. The repair company we contracted had to do fusion splicing in a john boat. 😅
Some times on our RTU's that don't have hot gas reheat its necessary to run both at the same time for de-humidification, the honeywell 8000 and 9000 series stats / eim modules allow this under the advanced settings for de-humidification. It is very effective with most package units where the evap coil is before the blower and heat exchanger, it just costs a ton to operate.
hello, i'd like to know when this situation happen can happen as usually when it's cold outside, even if 100% humidity, the % drop with heat and you often have too dry air, and in summer as you cool you dry it.
For strictly controlled environment like 20°C/50%RH I always see a heat exchanger in line to reheat after reached to required dew point.
Nest used to enable running both heat and cooling simultaneously for quick dehumidification, but they removed that feature years ago when it was taken over by Google
That would only work if the air runs over the condensor first. Otherwise no reduction in the dew point, as the AC just removes the sensible heat from the burner.
Generally air passes through the evaporator coil to the blower section, then through the blower wheel and across heat exchanger. Evap removes heat and moisture, then the heat exchanger adds the heat back while removing even more moisture. I’ve only ever seen it used in a pool room though.
@@jeremyduran8896 one of the main violators of this is the Goodman RTUs. The air goes through the blower then the heat exchanger and finally the evaporator before going back into the building.
@@WilliePeck I guess some units are like that but what a silly idea thinking about it... Evaporators will get heat cycled up to like 40-50c for no reason, can't be good for longevity
customer is made aware of the issue and they know you did a temp fix. so I see no issue. I like this channel.
Don't have to apologize for doing things like that cause you know what is really solving the issue, keep it like that! Every one of your videos are a great training!
its not supposed to be training, its what goes inside the mind of one (admittedly pretty good) HVACR guy's mind
When I was getting trained, I loved when the trainer would just ramble his thoughts outloud. Really helps get an understanding of a train of thought and how you're working through it. Awesome video as always
Always called those fixes, "temporary permanent". Love your fix!
i wouldnt ever worry about dropping a tstat into the return. we do that all the time, especially while you have to wait for the proper replacement for ems thermostats and sensors.
Love all your videos. Learning a lot with them. You're the best!🎉
He. Is. The best.
Or
Other one. is (Dave nor refrigerator
You owe no one an apology ... Good vid Bud ... And I'm wearing that same hat Thx ...
I run the CB 60hp water boiler at our church. I should have caught the problem. The blower motor was slow to get up to speed and close the air switch. We called the local company for CB boilers. After 4 days changing every part removing the blower mortar having it checked out they did replace the contractor (it came with the boiler 1960}. One side of the 220v. Was mostly mostly gone After watching you I should have checked the contractor myself but I left up to the professional men. they only billed us $8000.00
the new one sure wont last, unless it was pre 1990 new-old-stock(lol)
Another great video. Thanks for sharing. I wouldn't worry too much about people's comments about the t-stat in the return, that's normal practice.
Great job. I’ve done that before and it worked well. I definitely agree how you do the energy management.
I'm amazed that there is no interlock to either prioritize one side or lock both
I HAVE WATCHING YOUR VEDIOS FOR TOW YEARS AGO AND LEARNED A LOT .THANKS MAN GOD BLESS YOU.
IAM HVAC TECH FROM MICHIGAN
Nice work Chris.
Thank you, very much for sharing your knowledge
Good work, good ideas. Thanks, Chris,
Great Video. Thank you for sharing
I’ve done this a few times works great. Get you out of a jam.
I'm an engine Machinist & reconditioner and mechanic and there's one thing I was always told and that's called kiss (keep it simple stupid) and on a temporary fix to get it running again taking the least invasive plan of action is the most simple option. You can cause more problems later on by changing the thermostat in the building and having to mess around changing sensors and so on. So at the end of the day bypassing the in building thermostat and dropping the temporary one down the return duct is the best possible option for yourself and the customer.
Nice Job Chris!
I do like that Trane has a construction mode. You hang a 10k resistor and the unit will maintain 74 cooling and 72 for heating on its own, using the installed sensors.
I'm wondering how long "temporary" is. I know it's up to the customer, but few things are longer than a temporary fix that works.
Hey man, you’ve got good reasons based on your experience. I respect your decisions to do what you think is best and I don’t think you need to explain yourself but I understand why you did. Good stuff!
Nothing wrong with T-Stat in return. I work in food facility, people like to touch stat and always washing the walls. GOOD JOB!
Gotta always watch out for those dinggleberries😂😂😂
as norcal dave would say, MULTIPLE OFFENDER DELUXE
You have to do what's right for you everybody has there own way awesome video
0:03 - Wow, the thermal discoloration on the left contact is a rather dramatic shade of magenta I've never seen on contacts before!
I replaced a contactor today on a 20 ton Trane that fried from short cycling. I haven’t taken it apart yet, but from what I could see the internals were so burnt to the point of looking like charcoal. I even did the same thing of removing the lugs the way you did here, something I don’t normally do. I never really understood the point of doing so until I had to do it today.
That temp stat mounting reminded me of something. I was on an A/C call for a unit no heating and thermostat not working. Apparently, somebody did what you did over the summer, I assume system needed a thermostat and the company that condemned the thermostat sent out the new guy to swap the thermostat and that's all that happened. I had found the thermostat wires for inside the building disconnected and a cooling temp stat (The bulb kind) hanging infront of the air filters. I liked easy after-hours calls like that, BRINCO was the management company and it wouldn't surprise me if they approved the temp stat install, but only told a different company about the thermostat needing changed.
Today i replaced 4 relays, 2 of them because off a call-in, and the other 2 preventitive (finally, as we've been noting these 1990;s relays as being in a bad shape for years)
When mesuring across the contacts for Ohm's, i got a couple reading between 1~3kOhm and one relay even having 0,6 MOhm.
I installed a thermostat in the duct temporarily once and a different company came for a second opinion and their tech called me a hack lol
Big Picture! Multi-Offender! TY Great Video.
do you want cooling or heating?
yes
Why not both?
You should run for governor of California, with the smarts and logic you show in the trade I'm pretty sure you can gauge the state and see what's going on! and supply temporary fix, and also work for long term solutions!.
I did it before too and it work
It is a miracle if they had still any kind of functional connection to that digital thermostat/zone controller device in the first place as it has been soaked and corroded by cleaning chemicals and water so much that both cooling and heating calls are stuck on at the same time - though not indicated on the front panel LEDs.
So much corrosion and debris in there. I was first thinking that if there is even a factory bodge wire near the connector J5 on the front panel circuit board but after more careful looking it seems that is too some kind of debris flushed in.
I had to do a bit further research and at least some of those horizontal almost stacked bigger "chips" at the right side of the wall side board of the digital thermostat can be identified as CPC1976Y solid state AC switches, a kind of optoisolated semiconductor relay. It would have been actually interesting to see if more or less all of them were uncontrollably commanded on - or even fried on due to overvoltage like caused by a nearby lightning strike (I do not know how often you might have thunderstorms there).
I had the same thing going on three compressors on two 30 T Yorks with gas heat on found the DX9100 controller was programmed to a humidity set point at a plastic manufacturing plant so they we’re using as re-heat to not overcool space while trying to hit 60% RH
Southern California feels like Washington this year. I think I've seen the sun 5 times
i used to take an uninsulated butt connector, crimp it on the wires and put it in the lugs
Quick question with regards to the thermostat you put in the duct. Do you ever worry about the solid core thermostat wires breaking as the air blows it around in the duct? And what would you do if the thermostat did fall in the duct? Love the videos. Keep up the great quality work of yours.
Na those wires are tough they won't break in any short amount of time from swinging around a little. If it fell probably retrieve it or just leave it in the duct and get another one if you couldn't get to it.
I dont see an issue with what you did. I do that whenever needed because it works.
t-stat in the return duct works perfect nothing wrong with it, I use a stick of s clip tap the t stat to it bend a hook at the top of it and hook it to the filter slide so it doesn’t swing around around when the blower comes on, but still though nicely done it’s just temporary
Call Siemens tell them to send you new clam shell stat. Go back and put it in and replace your temp stat
The only thing I’ll say is if there are other units with t stats down the ductwork like that is it really a temporary fix? It all depends on a bunch of variables but if you have all the wires down in the restaurant to me putting it there is easier because you don’t need to run wire through the unit. I’m saying that if the staff plays with then ok but there is a screenlock on those Honeywells
Why don't the manufacturers make a failsafe to a set temperature when a dual call is made? Is there ever a reason for a dual call?
Gonna have to use that offer code! My truck was broken in to and all my tools were stolen.
Bummer
Totally with you Chris, drop the temporary t'stat down the return, absolute best place for it.
not sure how many times I've used a walk in t`stat dropped in like that in an emergency when you only need heat or cool.
Why not mount the t stat to the inner wall near the air return and run a sinsor to the duct work?
That was my birthday 🥳 I am 30 years old now
Love the video the first 22 seconds would make a great CZcams short
I had an issue with a thermostat. The costumer droped the face of the thermostat and the face of the thermostat loose some of the components inside the cause the wire of the thermostat to melt together and was causing the unit to trip. I had to run new thermoatat wire and ofcurse a new thermostat
That condenser fan 👻
Is there a company that rebuilds package units by using the structure and installing condensers, compressors, fans.etc.
Had the same issue with a 15 ton Carrier. Ended up being bad board tho. 1stage comp was also pretty unhappy to say the least haha. Also dropped plenty of temporary stats down the return duct. We have restaurants that have requested we leave them in there because they have less issue with employees playing with settings. To each there own. Let the haters hate.
That's called dehum in the south 😆. You can't do that with trane, the RTRM board will shut down.
Would have done the same thing myself it’s temporary cause those off sight control companies like to use specific stats that work with their monitoring system can be a pain but the unit will work fine and the customer won’t know the difference anyway
Big picture gang reporting. You wrap that duct mounted temporary thermostat in a plastic bag or does it go raw into the duct?
I just raw dogged it
Surprised the blower still works if its run on hi and low speed
If and when the EMC installs their replacement tstat, how is the EMC tech going to know there is a seperate "bypass" tstat in the RTU? They replace it - with the building tstat wiring not connected to the RTU. Finding the replacement EMC tstat with no power, does that then prompt a trip to the roof for them to find the "bypass" tstat in the duct, remove it & reinstall the original building wiring to complete the repair? Please explain.
probably wise to use a label printer and stick it on the bad thermostat. something like "bad t-stat, temporary one in return air on roof" 🤔
I'm curious, what do you do with the temp stat when you install the permanent stat?
Probably puts it back in the van for next time.
Save it for an emergency
Question... if the customer does not want to pay for a new EMS thermostat and decides to leave the system as is with the thermostat in the ductwork?
Lol there's no question there.
Why would you need a gas furnace in southern California I'm sure if they didn't turn the lights off overnight it wouldn't get cold Ive dropped tstats in return air duct many times times that's working smart
Dropped many temp stats down the returns over the years, ems operated thermostas are nothing but problems, they keep us busy year round though😅
Newbie into the trade here, if a liquid line port isn't available how much would Subcool change if the subcool was bring taken with discharge pressure and is there a way to figure out true Subcool with the discharge pressure and LST?
On carrier package unit with fixed orifice metering devices I usually see about a 35psig pressure difference from liquid to discharge ports... but each manufacturer is gonna change depending on their design
I assume they have kitchen friendly water resistant thermostats? From my younger days working in restaurants I have seen those deep clean crews take a spray hose to kitchens at times.
Or is "hardened" just the old honeywell thermostat from Grandma's hose with the mercury switch? 🤣
Calling for heat and cool at the same time should be able to be INDICATED as a POSSIBLE error condition with a few lines of code. Marketing wienies like to sell/charge more for "features".
At least Lennox has that on some of their RTUs, I think it’s error 86 on L series units.
Yeah but if somebody dumps water on your unit …. Good luck. ;-)
How upset was the customer when you told them how the t~stat was damaged? Or do you just say it was damaged?
Do you mark up equipment you sell like mechanic shops do to make profit? Or do you still make money from just the installation?
Hi don't get me wrong, but I have a question. I am electrician living in Germany and for me the wiring looks like a DIY project.
Is that standard in the US or is that not normal in the US as well?
Won't that help with humidity?
why didnt you install it on the wall where the dead stat was? not complaining just wondering
I will discuss this on my Livestream this evening 3/20/23 @ 5:PM (pacific) over on CZcams come over and check it out czcams.com/users/livevKpJKA-Y51U
5:58 My standard answer is, "because they're dumbs**ts". I'm sooooooo mean!
I've done that plenty of times to get a unit running don't see why anyone would have a problem with thermostat in the return as a temporary 😂
If wires have quick disconnects on them I just clip it and put it in the lugs of the contactor haven't had a problem doing that.
Those Carrier "low-cost" RTUs are a bit of a joke. And I would think the microcontroller would inhibit the heat call if there was a cooling call, or error out and do nothing.
so, it was a huge inefficient dehumidifier. 🤣
CHRIS, YOU NEED TO UPDATE YOUR MEME!!!!!!!! 🧔🏻 🧔🏻 🧔🏻 🧔🏻 🧔🏻 🧔🏻
woo March
If I was a thermostat I would want to live in a nice comfy duct with cool filtered air passing over me instead of being in some greasy kitchen.
Min 2:00
In other words, the thermostat is calling for Heat and AC at the same time? (???)
I've done it several times. Let it hang. hahaha
10:00 Why can't you just replace the busted thermostat in the building though?
He can, but as he states it's going to take a while to get.
Energy Management was a service I did not think did much more than collect money and install equipment. If the multi-figure-$-electric bill went down on a large building, resulting in a realized return gain on investment, all is good. (Not my job to know those things). Since I maintained the older more mechanical side of equipment generally, the electronic takeover folks would “”move”” alarm sense wires going to our national operation center, to another companies monitor and dispatch center, (not in-house control any-longer).. With that written: The building gets very warm one day, (temperature control is critical inside this building). The electronic monitor folks did not dispatch out a facility tech., possibly saw or ignored; “high-temp building alarm”. Management has no clue why the new monitoring alerting failed to roll someone to the site, (that is another story). Plenty of finger pointing. I could not even guess the 💵 the company invested in the new system. Had zone temp. measuring sensors on floor pillars all over. All a waste of cash. (The high temps were detected by someone physically on the floor, most every time. (Back when companies had a few more employees). High temp “dispatch-tech.-out” was set around 90 degrees, (I learned through a facility /building tech.). I was in a different type of equipment maintenance group. (The olden days). 😊 Good topic Chris, as usual.
Room Temperature Air + Heated Air + Airconditioned Air = Room Temperature Conditioned Air = No Problem.... I have doublechecked and the equation is sound.
also it is super inefficient. it makes no sense to run both at the same time. also the unit is not designed to run both. kind of a hazard
@@mitchellmorrison4233 true enough
Are the contactors dying so much because they're bad quality?
in this case it seems to have been caused by it constantly switching on/off, and melted the points from the heat build up
They have a big problem in Southern California with dust/sand
due to ROHS all the "good" elements have been removed from the contact material composition, like "cadmium", so they're all using alternative compositions, which doesn't hol dup as well. but that thing was likely chattering the contactor and doing all sorts of bad things to it.
There’s nothing wrong with doing that. I’ve done it many times in the past. It’s only temporary.
My only point of contingency is dropping a visionPro down the return. Thats a 250$ tstat 😂
"internet controlled thermostats?" get them off the internet immediately they being on the internet is nothing but trouble hackers can hack them and wreak havoc on the business.
for example a hacker can turn them up to full blast to full temperature and run up the energy bills.
a scenario it is a wax museum and the wax statues are made from the low melting cosmetic/beauty grade wax a hacker hacks into the thermostats and turns the heat on to the max (i think it is like 9 degrees).
the statues melt and all the priceless statues are destroyed
if the hacker is not interested in the destruction of wax statues they could get the login/ssl credentials from the iot device and use that to authenticate as the museum (that is what happened to target a couple years ago)
i am not sure how the ducting is plumbed on a package unit but in a residential furnace the air blows over the heat exchanger for the heat then over the "A" coil for the air conditioner.
if packaged units work the same way it is possible that the short cycling is being caused by the air conditioner going off on high pressure.
putting the thermostat in the duct may be dumb but if the business is one of them kind that would stand to lose lots of money to customers not doing business there they need the system to work now so installing a temporary thermostat in the ducts is your only choice so i cant call you dumb for doing that because many businesses are in a pinch and need their systems working.
Why is heating done with gas down there? You have perfectly working heat pumps.
It's a old system
@@labombao7725 I haven't seen on any of his video a reversible AC...
But if the wires were shorted in the wall you would have needed to disconnect W1 otherwise it just loops back through the short. Shorted wires could have wrecked the contact too. So I wasn’t as positive as you that the stat was a goner but I love asking engineer questions or I will never learn and just keep annoying techs who know better!!(haha)
Granted the stat had gotten wet but could you have left W off and see if it ran in cooling if there wasn’t much need for heat.
I felt the same; It seems like we didn’t test if the t-stat/t-stat wires were bad. Because we didn’t disconnect the wires at the t-stat. Might be something I missed. I apologize if my comment is obtuse.
Once I saw the corrosion I knew it was the Stat, but what you all didn't see was I had to change another one for the same reason that day too....
Who cares what other people want you done good
193 thumbs uP