I was doing a rare Preventive Maintenance today, and thought I’d share how to test defrost. #hvac #hvaclife #fieldpiece #rheem #makita #defrost #shorts
Haven't seen many videos on the Adaptive Demand Defrost on residential heat pumps. I'm not an HVAC tech but bought a spare board after I had a failure to learn the difference. Not dramatic, but their are differences. The "test" pin is really just taking a pin on the chip high to signal defrost. The selector is termination temperature instead of run time. So if you need more defrost, you'd raise the term temp. My board defaults to a 30 timer function if the ambient thermistor fails. If the coil thermistor fails, defrost doesn't run. And upon first defrosts after the board has had the 24 vac R cycled, the it does a few timed cycles while it relearns and begins adaptive defrost.
I have seen a large number of those “failures” caused by frogs, snakes, lizards, and skinks. Sometimes I diagnose a failure and don’t see the critter until I remove the board.
You are so right my man last year I had a heat pump that the wire nut on the red wire one of the wires came loose and defrost never happened even though the system operating
Well, that was a review for you and others on how to test defrost on heat pump. Myself and perhaps others did not have a camera angle, but worse a poor lesson on what has and will take place. But thanks
That's obviously an interval time/temperature board. For demand boards are there test pins or something you can force a defrost with an insulated screwdriver while it's running in heat with the fan on?
Yes, some boards, like some trane boards I’ve seen, you just hit the test pins and it goes into defrost immediately if it’s in heat. That’s not a real good test though - sensor can still be faulty. In that case you need to ohm out the sensor and check it against temperature. But, you’re right about time and temperature on this board. Most Carrier and Goodman boards also use time and temp. But, they have a defrost thermostat instead of a sensor.
I'm in Ohio (different climate then you're used to) but wondering if I should switch to heat strips when it dips below 32°F or just let the system do its own thing? I have a new Payne 3.5 ton just installed this past summer
Depends on the heat pump. Most start losing ability to produce heat when it gets close to freezing. Some of the inverter driven heat pumps advertise that they can produce heat well below zero. Something like that would eliminate the need for heat strips around here.
@@staind288 What you need to look for is the balance points for your equipment. Heat strips should automatically stage on as temperature falls below these points. Remember, even if it is very cold outside, the heat pump will generate heat at a better c.o.p. than electric strips alone. What will happen is the structure will lose heat faster than the heat pump refrigeration cycle can generate heat. In other words the balance point. Supplement or aux heat is then brought on in the next stage.
Copeland has came out literature last year that they don’t want you forcing defrost on their compressors. Something along the lines the scrolls spin backwards for the first second and is killing them left and right
i know i set my heat pump to 68 and never touch it again till it starts warming up again , then it's ceiling fan weather with windows open till it gets hot and then i set my ac to 74 and never touch it. just me and the dog now and she never complains, LOL
love seeing all of your Videos. Great
Good job Curtis.
Haven't seen many videos on the Adaptive Demand Defrost on residential heat pumps. I'm not an HVAC tech but bought a spare board after I had a failure to learn the difference. Not dramatic, but their are differences. The "test" pin is really just taking a pin on the chip high to signal defrost. The selector is termination temperature instead of run time. So if you need more defrost, you'd raise the term temp. My board defaults to a 30 timer function if the ambient thermistor fails. If the coil thermistor fails, defrost doesn't run. And upon first defrosts after the board has had the 24 vac R cycled, the it does a few timed cycles while it relearns and begins adaptive defrost.
I have seen a large number of those “failures” caused by frogs, snakes, lizards, and skinks. Sometimes I diagnose a failure and don’t see the critter until I remove the board.
Nice intro man, I like it! 🔥
Nice explanation on defrost board.
We do not have to many heat pumps in new England.
I've got one.. a good 300-400 miles northeast of you ;p
Shpuldnt have any there. Oil burners and furnaces unless you got a duel fuel heat pump
@@alexprowse5120 They're everywhere around here. Mini splits and central systems. Backup electric heat strips.
Good one 👍
You are so right my man last year I had a heat pump that the wire nut on the red wire one of the wires came loose and defrost never happened even though the system operating
Yep
Well, that was a review for you and others on how to test defrost on heat pump. Myself and perhaps others did not have a camera angle, but worse a poor lesson on what has and will take place. But thanks
That's obviously an interval time/temperature board. For demand boards are there test pins or something you can force a defrost with an insulated screwdriver while it's running in heat with the fan on?
Yes, some boards, like some trane boards I’ve seen, you just hit the test pins and it goes into defrost immediately if it’s in heat. That’s not a real good test though - sensor can still be faulty. In that case you need to ohm out the sensor and check it against temperature. But, you’re right about time and temperature on this board. Most Carrier and Goodman boards also use time and temp. But, they have a defrost thermostat instead of a sensor.
Older folks seem to get cold easy. Probably felt good to them.
I'm in Ohio (different climate then you're used to) but wondering if I should switch to heat strips when it dips below 32°F or just let the system do its own thing? I have a new Payne 3.5 ton just installed this past summer
Depends on the heat pump. Most start losing ability to produce heat when it gets close to freezing. Some of the inverter driven heat pumps advertise that they can produce heat well below zero. Something like that would eliminate the need for heat strips around here.
@@HVACGUY how would I find this info?would it be in the manual provided by the hvac installer?
@@staind288 What you need to look for is the balance points for your equipment. Heat strips should automatically stage on as temperature falls below these points. Remember, even if it is very cold outside, the heat pump will generate heat at a better c.o.p. than electric strips alone. What will happen is the structure will lose heat faster than the heat pump refrigeration cycle can generate heat. In other words the balance point. Supplement or aux heat is then brought on in the next stage.
Where do you get your reversible nut driver tips on your screw gun?
United Refrigeration, baker distributing. Plus, they have some at Home Depot
Thanks friend.
👍
Copeland has came out literature last year that they don’t want you forcing defrost on their compressors. Something along the lines the scrolls spin backwards for the first second and is killing them left and right
It's surprising they stop/start them like that. Used to just keep compressor running and switch reversing valve.
I gave u a 2 thumbs up HVAC Guy!
How can you work with electricity for so long and be so scared of it?
Finally a unit not in the jungle. 😀
Heat set at 82. OMG. To me it's kind of like people setting a/c's at 68. Not too many heat pumps in S. Florida.
i know i set my heat pump to 68 and never touch it again till it starts warming up again , then it's ceiling fan weather with windows open till it gets hot and then i set my ac to 74 and never touch it. just me and the dog now and she never complains, LOL
My a/c is on 73 during the day and 65 at night
My mom's 89 and keeps it at 80 degrees year round. That's a big tree stump.
Thanks for the tip.
🥃🥃🍺🍺🍺🎯🏌🏻♀️
Stay safe.
Retired (werk'n)keyboard super tech. Wear your safety glasses!