emergency heat - heat pump concern

[amandalynnwrigh]

SWF, first time homeowner, have heat pump. Before it got very cold (about 45 degrees F) the blue aux heat light was on most of the time when the heat kicked on and only turned off a few minutes before forced air stopped blowing. Now that it's below freezing every night and sometimes all day, I notice the red emergency heat light comes on after the heat has been on for a few minutes. I've read through many of the threads to see if the red light is normal, and now I have another concern about the aux heat being on so much. Also, I've never had a heat pump before and I always turn down the thermostat when I leave the house and go to bed, which may not be the best thing to do according to some of the threads. So, I have a few questions:

1. Should I leave the thermostat at one temp at all times?
2. Should the aux heat light be on most of the time?
3. Is it okay for the red emergency heat light to be one when it's really cold outside?
4. What is the difference between aux heat and emergency heat?

I'm a pretty good do-it-yourselfer, so I'm not afraid of trying to fix or clean something, I just have no experience with a heat pump. If there is something wrong with the behavior of the HP explained above, I'd really appreciate advice on trying to remedy the problem myself before calling a service person.

[hvac4u]

turning it down when you are away will cause the aux to run for a prolonged period of time

the red light may indicarte that an outdoor sensor has determined that it is yoo cold out to make it worth running the heat pump, and goes to straight aux heat

feel the large copper line leaving the outdoor unit, it should be hot, let us know

[Grady]

Depending on the system & how it is wired, the thermostat might be giving you erroneous signals. If the thermostat is not digital, remove the cover. You should see two vials with mercury in them. Set the thermostat below room temperature. Leave things alone for about 5 minutes. With the thermostat set for heat, SLOWLY increase the setting until just one vial tips. If the aux. light comes on, something is probably wired wrong. With this setting the outdoor unit should be running along with the blower indoors. The large copper tube from the outdoor unit should be warm to hot.
With most heat pumps, I suggest setting the thermostat to a temperature at which you are comfortable & leaving it alone.

[amandalynnwrigh]

Okay, I came home today around noon, and the temp outside was around 46 degrees F. The heat was not on when I came home (although it was yesterday at noon, it was 49 outside and emergency heat was on), so I turned up the tstat until it clicked on and forced air came on. I went outside and at first the fan on the outside unit was not going, but after about 1-2 minutes the fan started. After a few seconds, the large copper line outside was was hot (although I did notice some rodent damage on the insulation of this line - I will fix this soon)

I also removed the cover of the tstat and it does have the mercury viles. I did notice that it is not very secure on the wall and that it was not level. Might this be contributing to a problem? So, I slowly turned up the setting until one vile tipped. This turned on the heat, without the aux light coming on. I turned it a bit futher, the other vile tipped, aux light came on. I assume this is how it's supposed to work?

Since I've been home, I've been watching the tstat like a hawk and, of course, it is not acting strangly now. However, this morning when I woke up (outside temp 29) the heater was running on emergency heat.

I've read through some other threads and do you think I could be low on refrigerant?

If there is a sensor outside affecting the aux and EM heat, is it typically easy to find and adjust if necessary?

I think I have a Coleman Evcon heat pump, came with manufactured house, built in 1990.

[Ed Imeduc]

Id check and set the tstat to the wall tight and level.Plug any hole in the wall there in back of it so no draft can get to it from there.
I also removed the cover of the tstat and it does have the mercury viles. I did notice that it is not very secure on the wall and that it was not level. Might this be contributing to a problem? So, I slowly turned up the setting until one vile tipped. This turned on the heat, without the aux light coming on. I turned it a bit futher, the other vile tipped, aux light came on. I assume this is how it's supposed to work?
Sounds like its ok. just set it and let it alone . like Matt said it dont pay to push a heat pump down and then have it try and bring back up the temp. After it has run for a bit is the big copper line still hot there at the inside coil ??

ED ;)

[Grady]

The next time you see the emergency heat light on, go outside & see if the outdoor fan is running. If it is not, check the thermostat about every 5-10 minutes to see if the emergency heat light is still on. I am suspecting when the emergency heat light is on, the unit is in defrost mode. When it comes out of defrost, the outdoor fan should start & the emergency heat light should go out. This one is a puzzler. Keep us posted on what's going on.

[amandalynnwrigh]

Okay, I leveled and secured the tstat to the wall. Everything seemed fine for a long time, but it may have been just because it warmed up. It got near 60 degrees yesterday, spring is definately coming. Anyway, the heat would kick on occasionally, no aux light, no EM light.

Then, after nightfall, outside started to cool down, and I noticed the aux light on. I removed the cover of the tstat and the second vile was not tipped, which puzzled me because I thought the tipping was what triggered the aux heat. Well, I kind of gave up on it and went to bed, leaving it set at 70 degrees.

Then, I kept waking up, feeling really hot because I normally turned it down to 65 until the advice so I left it at 70, and I kept noticing the EM heat was on, everytime I woke up and looked at it. I bought an indoor thermometer yesterday, and the temp in the house was indeed 70. Finally, I just turned it down to 65 because I was too hot.

Now, it seems to be working "normally" again; no aux light, no EM light. Could it be that it just doesn't work effeciently above 65? Could the tstat get stuck on AUX or EM and just not switch back over until it's done heating? Would it be inefficient to get an electric space heater for the living room when I want it at 70 degrees in the evening? Could I just need a new tstat?

When I get home today I'll do what Grady suggests and get back to you.

[amandalynnwrigh]

Well, finally gave in and called a service person. The problem just kept getting worse, no matter what I tried. So, looks like the circuit board needs replaced. I'll keep you updated if something else is to blame...