[slgroves]

We have a heat pump that was serviced last year & seemed to work fine. However, when the temperature dropped to 9 degrees last night, the house kept getting cooler and cooler. The aux will kick on, but it never closes that last 5 degrees. The same is true for the emergency heat; it's always at least 5 degrees less than we want and then just runs and runs. The emergency heat even starts by blowing cool air. It turns to warm when the aux light comes on (whether it's on heat or emergency) and gets cool again when it's not on, making my temperature drop until the aux/emergency kicks back in. My second floor is also about 5 degrees cooler than the main floor. The heat pump is in the basement beneath the main floor. Any suggestions? We normally try to keep the house at about 73 degrees. Last night we kept getting up to tinker with the system every time it got down to about 70. By manually turning up the heat to over 80, we could get the main floor to about 72 degrees, but it was still 67 in my daughter's room upstairs. Am I just one of the loonies who doesn't understand a heat pump or should I get it serviced?

[dac122]

I've seen a number of posts around today about folks HVAC systems not keeping up with the unusually low temps in the US right now. You system may have been sized to meet a design temp a little higher than you are now experiencing.

At 9F you are relying almost exclusively on your aux heat. The only way to fix that problem is with higher capacity aux heat. If you have electric heat strips you'll need to add more or replace them with larger strips.

If these are normal temps for your area then something else is wrong.

[KC13]

The indicators on the thermostat are no guarantee that the system is working properly, only that a demand for a function is present. If the system has performed well in similar conditions in the past, a call to a pro might be in order.

[slgroves]

Thanks for the answers. The heat pump is now getting it up to 73 or so on the main floor(it's up to about 15 degrees outside), but it's still 70 upstairs. How do I find someone to service my unit? It seems that people won't come unless they installed the unit & the guy who installed it couldn't fix this problem last year (told us it was fixed, actually). Would a programmable thermostat help?

[hvac1000]

My company always ran service calls when money was involved. I just loved to fix things back then.

[slgroves]

My company always ran service calls when money was involved. I just loved to fix things back then.

Wish you were around here!:)

[hvac1000]

BTW a new thermostat will not make the unit generate more heat. It is a good possibility that one or more of the strip heaters in the electric furnace itself is not working. That would cause the electric furnace not to keep up when it is extremely cold and the heat pump is not working. Most heat pumps loose there capacity to save you money at about 20 to 25 degrees. They will run but your just spinning the compressor so it is better to have them just shut off and let the electric heat run.

Depending upon how your system was set up originally it would be wise if you find a service person to bring this to there attention also. Have the heaters checked in the furnace.

[slgroves]

Is it possible that the electric heat was never correctly hooked up? When it's on emergency the blower comes on by itself and seems to blow nothing but cold air at the beginning, then the aux comes on later when the temp. dips another five or six degrees. But once it gets to about 5 degrees below what we're aiming for, the aux heat seems to shut off but the blower keeps blowing cold and will continue to keep blowing until the temp dips another five or six degrees turning the aux back on again. So, the blower never shuts off. Shouldn't the emergency heat kick on the aux at first and keep it on until it hits its thermostat mark and the blower shut off a little time after?

[hvac1000]

Shouldn't the emergency heat kick on the aux at first and keep it on until it hits its thermostat mark and the blower shut off a little time after?

When the heat pump can no longer provide economical heat then the emergency/auxilery/heat strips should come on and take the temperature to where it is set at on the thermostat under normal circumstances. For all purposes the heat strips should be able to heat the home without the use of the heat pump.

[KC13]

This new info you have provided is suggesting that you may have more than one problem. Any or all of these might apply: 1)If you have a mercury-type thermostat, it may not be mounted level and is inaccurate as a result. 2) Thermostat and/or indoor unit not wired correctly to provide proper control of auxiliary heating stages. 3) One or more auxiliary heaters not working due to a part failure (heater string, heat relay, limit control, fusible link, wiring, etc.).

[slgroves]

Thank you for actually providing an explanation here folks. I haven't been able to get half of this info out of our heating person who installed this system. So, I really appreciate the troubleshooting you folks are doing.

That being said, I tend to think it is the scenario number two that KC13 has outlined. If you bump up the thermostat so it hits the second bubble (turning on the aux or emerg. Heat whatever you want to call it) it will blow nice warm air. I tend to think either the thermostat wasn't wired correctly for the emergency heating stage or it wasn't wired correctly at the electric furnace level. Either way I want to get it looked at if I can ever convince any heating folks to come and look at it in our area. You wouldn't believe how many have put us off because they didn't install the system. All we have called so far have said we can pretty much forget about it till after the holidays.

The good news is that I have it on the regular (heat pump on) cycle now and the temperature was a warm 13 degrees this morning, it seems to be heating the house up to temp (roughly 73 degrees). It runs a good bit, but still shuts off every once in awhile. This tends to make me think it is not a heating coil problem (even though I would like to check on that too), but a simple wiring one with the emergency heat. I sure wish I could some heating folks like you to come take a look at it!

[KC13]

13 degrees, eh? Unfortunately, you won't be luring many visitors with the promise of nice weather!:cool:

[hvac1000]

Hopefully it will operate over the holidays with no problem. Merry Christmas.