Disable AUX Heat on heat pump?

[Gila Monster]

So this is a follow up to my earlier post regarding my heat pump.

I think it may be malfunctioning and could be the reason why my bills are higher than they should be.

Basically everytime the heat comes on, the "AUX Heat" light on my thermostat also comes on and stays on.

My understanding is this should only come on if it's especially cold out side or I go from a large swing in the set temperature on the thermostat. In my case, none of these things are happening, yet the AUX heat stays on.

An example, if say I go from 68 to 69 degrees and the outside temp is 50 degrees, the AUX HEAT light comes on and will stay on the entire cycle.

Is this something I should look into disabling?

http://hvac-talk.com/vbb/showthread.php?727001-Disable-aux-heat

Thanks for the advice

 

[Stuff]

Usually AUX heat is more expensive so yes, you should look into fixing the thermostat. What brand and model? It might just be a setting if it is digital.

 

[crabjoe]

Check the wiring of your t-stat to your air handler. It could be setup to energize your heat strips whenever your heat pump runs.

 

[bazar01]

Are you sure you have a heat pump?
That is the first thing you need to check. (Brand/Model# check)
Then check how the aux heat is wired to the thermostat. (Brand/Model# will help)
Then check how the parameters on the thermostat were programmed.
Post back.

 

[Gila Monster]

Are you sure you have a heat pump?
That is the first thing you need to check. (Brand/Model# check)
Then check how the aux heat is wired to the thermostat. (Brand/Model# will help)
Then check how the parameters on the thermostat were programmed.
Post back.

Yes on being sure it's a heat pump, the outside unit's ID tag says "Heat Pump" on it. It's a Trane, the inside air handler is an American Standard, along with thermostat.

I'm thinking this is how the AUX HEAT is adjusted, I never even knew it had this feature. It's a screw on the back

How exactly does this work?

 

[dreasoner]

That screw simply changes the heat anticipator setting. Where is it set at?

 

[bonneyman]

Looks like an older Honeywell Chronotherm 3 stat.

Pull out the booklet, and get into the advanced programming on the front. Scroll through till you get to the "differential" temp. Usually it should be set at 3 degrees. In other words, if the temp is set to 75, the temp will have to drop to 72 with the unit still running to activate the auxillary heat.

 

[Gila Monster]

Looks like an older Honeywell Chronotherm 3 stat.

Pull out the booklet, and get into the advanced programming on the front. Scroll through till you get to the "differential" temp. Usually it should be set at 3 degrees. In other words, if the temp is set to 75, the temp will have to drop to 72 with the unit still running to activate the auxillary heat.

The manual is probably long gone, it was what was in the house when I moved in. My guess is it's close to 1998 as that's the date on the air handler.

Any idea what direction I should turn the screw? Does clockwise or counterclockwise make that temp range expand or contract?

My goal is to use the AUX Heat as little as possible, right now, that light basically comes on and stays on, even if I'm just bumping up the temp a single degree and it's nowhere near freezing outside.

 

[east_tn_emc]

Has this been happening for a long time, or is it a recent development? If recent, have you recently made any changes to the t-stat or any other part of the hvac system?

 

[pop pop]

Maybe your heat pump is malfunctioning and your only/primary source of heat is the aux. heat??

 

[Gila Monster]

I'm not sure when it began or if it's a malfunction. I thought I would try first and make some adjustments and see what happens.

It may have been something where the previous owner just didn't care about the utility bill and had the AUX heat come on whenever the heat was engaged.

But as far as that screw goes, how is it adjusted? I thought I would start there.

 

[slice]

Leave that alone. Nothing to do with aux strips. Determine if outside unit is even running. If so then yes you could have a stuck heat sequencer aux heat on the time. Or the old stat could be shorted out. Too many variables. Maybe a pro needs to have a look.

 

[SuperD]

I have a 2 stage heat pump with back-up electrical heat, had it since new in my home. I know about heat pumps, had to rewire minr (lots of online information and a back ground in automotive A/C and controls with factory GM training helped) because the heating guy did not know what he was doing. I had a friend install this (first mistake) he would not set it up so back-up heat worked, would not run back-up during the defrost mode, and would run the fan continues during A/C mode. Within warranty it sprung a leak on the indoor coil (I called a good contractor after I noticed compressor noise) cost me $500.00 for items that the warranty did not include such as recharge and service call. My point is, if all that I wrote about and is jargon for you, I think it is time for you to ask friends about a good installer contractor to get your system repaired. These systems are complicated, nothing wrong to hire a pro, ask around to builders perhaps someone who has been around for at least 10 years.

You'll be happy to have the system working as it should.

 

[Rkbuell]

A little I know from a heat pump system I used to have, both units must be heat pump, if you have a regular air handler then the heat strips are the only heat and the t-stat would likely show aux heat to get them on. So I would say you need to be certain air handler is also a heat pump unit. Also must people waste money and time with self repair on have systems

 

[Gila Monster]

Hire a pro? Seriously, this could be as something as simple as swapping out a Thermostat. It's about as dangerous as changing out a light switch. I'm not messing with the refrigerant or anything.

I was a hoping a DIY site like Garage Journal (in the Heating and AC section no less) would have a more "can do" attitude.

Hoping to do some more diagnosis first

 

[TangoFoxTrot]

Hire a pro? Seriously, this could be as something as simple as swapping out a Thermostat. It's about as dangerous as changing out a light switch. I'm not messing with the refrigerant or anything.

I agree, I think it could be just a bad thermostat, especially considering the age. $20 for a new one at Home Depot and a few minutes could be all that's needed to fix.

If it's otherwise working properly, that would be my first guess.

 

[larry_g]

I'm not sure when it began or if it's a malfunction. I thought I would try first and make some adjustments and see what happens.

It may have been something where the previous owner just didn't care about the utility bill and had the AUX heat come on whenever the heat was engaged.

But as far as that screw goes, how is it adjusted? I thought I would start there.

Hire a pro? Seriously, this could be as something as simple as swapping out a Thermostat. It's about as dangerous as changing out a light switch. I'm not messing with the refrigerant or anything.

I was a hoping a DIY site like Garage Journal (in the Heating and AC section no less) would have a more "can do" attitude.

Hoping to do some more diagnosis first

You have no idea what is going on, post a lot of coulda and maybe's and then get offended when it's suggested you get a pro? That is why us pro's make the big money, we know what is going on and which knob to turn. You just go ahead and do what you can and then a pro will come along and fix the problem and undo all the additional ones you infused into the works. Please keep a list of what you do to show to the pro so they don't have to charge you additional trouble shooting time to discover problems that would never be naturally.

lg
no neat sig line

 

[404]

Is this your thermostat? If not can you take pics of the front so we can identify?

https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-0690.pdf

 

[yeldogt]

How many heating seasons have you been in the house -- it's sounds like you are new to the place and making assumptions on the cost?

Find the breaker fro the resistance heat and turn it off -- see of you are getting heat from the heat pump. Is the outside unit running -- sound OK?

The older heat pumps would not provide enough heat when the temps dropped -- it was not that they were not working -- the BTU's just dropped off.

Do you have a back up furnace? -- or only a heat pump? If it's 25 outside the aux is going to be needed with an older heat pump.

 

[bazar01]

Hire a pro? Seriously, this could be as something as simple as swapping out a Thermostat. It's about as dangerous as changing out a light switch. I'm not messing with the refrigerant or anything.

I was a hoping a DIY site like Garage Journal (in the Heating and AC section no less) would have a more "can do" attitude.

Hoping to do some more diagnosis first

Good luck with your diy.
If you still have not figured out by now, after all the suggestions, time to get a pro.
Or just turn off the circuit breaker to the heat strips would be best as suggested by yeldogt.

 

[Gila Monster]

So I figured it out, I have a thermostat issue.

I have that same one that 404 posted a link to, only difference was "American Standard" is on the face instead of "Honeywell" (thanks to both bonneyman and 404 for identifying it)

Was able to swap on the same one, I have a 2nd one that is identical for the other zone. Heat strips are not coming on.

Glad it got resolved

 

[404]

So I figured it out, I have a thermostat issue.

I have that same one that 404 posted a link to, only difference was "American Standard" is on the face instead of "Honeywell" (thanks to both bonneyman and 404 for identifying it)

Was able to swap on the same one, I have a 2nd one that is identical for the other zone. Heat strips are not coming on.

Glad it got resolved

Feels real good when one is that lucky!!! with an easy fix!!!
Congratulations and well done. With all the money you just saved you can get a lift for the garage.