HVAC question: is my heat pump broken?

[MillCreek]

I have our heat pump set to come on in the mornings before we leave for work and upon our return in the afternoon.  I set it at 68 degrees and I have noted in the past that the interior temp generally increases at a rate of about four degrees per hour.

Both yesterday evening and this morning, the interior temp never got above 66 degrees and the air coming out of the registers was cool.  We have a conventional heat pump/electric air handler system with auxiliary electric heating strips in the air handler.  I reset the system via the thermostat this morning (turning it from auto, to off, and then back on to auto). I will be interested to see if it is working this evening.  The system was working fine as of two days ago.

Any thoughts on what the problem could be and if there is anything I can do at home to solve it?  Or is this a service call to the friendly technicians?

[Ben]

This is exactly what was going on with the system here when I moved in. I'm a dummy with the HVAC stuff, but I recall that the tech said there was likely a leak in the system somewhere. They could have spent time diagnosing and tracing, which he said could be cheap or expensive depending on where the leak was and how long it took to find it, but for a variety of reasons I went with a new HVAC system.

Anyway, same as yours - checking with an IR thermometer, It was blowing like 70deg and wouldn't go higher. Which of course wouldn't get the house anywhere near 70deg. Another possibility might be it's stuck in defrost mode? That would blow cool air as well. Definitely check the temp at various registers with a thermometer though.

[Nick1911]

You'll probably want to have a technician look it over.

Is your outdoor heat pump actually running?

[castle key]

Are you amenable to a cis gendered white male technician servicing the system?

[Jim147]

Check your air filter if you haven't and then like Nick said make sure the unit is runnning. Hopefully they wired it with an emergency switch so you can go to the power sucking strips if needed.

[MillCreek]

Check your air filter if you haven't and then like Nick said make sure the unit is runnning. Hopefully they wired it with an emergency switch so you can go to the power sucking strips if needed.

'Emergency heat' is one of the system options on the Honeywell thermostat.

[Brad Johnson]

You'll probably want to have a technician look it over.

Is your outdoor heat pump actually running?

This. Could be a simple a fragged contactor or a faulty reversing valve.

Also, make sure your condenser coils are clean. Heat pumps are hella sensitive to blocked coils.

Brad

[MillCreek]

So I arrive home, the house is at 68 degrees, the outside heat pump is spinning quietly away and warm air is coming out of the registers.  The heat pump clearly sensed that I was invoking the A-team here, and decided to get with the program.  Hmmm.

[Jim147]

Look at the coldest day in the extended forecast. That is the day it will die.

[JTHunter]

What Ben said about a possible leak is accurate and makes sense IF your system runs for a longer than usual or cycles more frequently.

Not a heat pump but my furnace is an 18 y.o. nat. gas and wouldn't come on Monday.  I heard the inducer motor (to create draft in the flue) come on, runf for about a minute, then stop.  There was no "click" of the hot surface igniter or the main burners coming on and I was afraid it was the electronic control module (ECM) which had failed twice in 3 years (damned electronics !!) at just over $500 each time. 
After taking the chimney apart to gain access the inducer (after finding no problems with the vacuum line), he looked into the housing and said the impeller had disintegrated.
They brought out another motor but that damned thing cost $779.oo !!!  Then there was the $99 service call on top of that (of course).