Configuration question - thermostat/heat pump
I have a brand new carrier 4-ton 15 SEER heat pump that was just installed on Monday. This morning I woke up and found the heat running around 6am. I got to work and my wife called me and said the heat was still running. After reviewing everything we found the following:
1. The "Aux heat" indicator appeared on the thermostat display
2. The air coming out of the vents was only slightly warmer than room temperature.
3. Thermostat heat temp was set to 77 degrees
4. The air handler did not shut off for hours all morning, we had to manually turn off the system at the thermostat.
5. Overnight temp was in the 40s and 50s which is why the heat was running.
6. After hours of running the heat, the temp was up to 77 when I got up this morning, but hours after this while at work my wife called and the temp actually dropped by a degree, so it was getting cooler not warmer.
We called the installer back and they sent someone over to check. Of course after they turned the system back on it worked fine and they couldn't find a problem. They probably think we are idiots and mis-configured the thermostat. It has worked fine as I programmed it up until this morning, and I'm a technically minded guy and familiar with HVAC and thermostat configuration, so I don't think its a mis-configuration on the thermostat schedule settings.
We got a new honeywell 7-day programmable touch screen thermostat. Its the VisionPro 8000 model.
My question is this: Could there be a setting the installer did not configure properly? I could go through all the installer configuration screens on the thermostat and see what things are set to. But to be honest, I don't know what configuration settings work with our heat pump. So if something was set wrong, I wouldn't know.
We have the carrier performance series 15 SEER outdoor pump, and a matching indoor air handler. If anyone knows what settings I should be using, or could point me in the right direction, I'd appreciate it.
Last edited by joechurch; 03-14-2008 at 01:41 PM.
Reason: spelling corrections
Does sound like something is going on. Even as hot as you are wanting it inside, a heat pump should do pretty well at it when in the 40s/50s outside. If it were in the 30s and you wanted it that toasty, I could see it running nonstop and asking for backup.
Sometime when it is not calling for aux heat on the stat, use a probe type thermomometer and check return & supply temps at the blower unit. Often can get at home stores, car part stores or Radio Shack. Temp rise should be 25-30 or more in 40/50 weather out.
Check to see if the outdoor unit is running the next time this happens, they may have it set to shut itself off when the OD temp drops.
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I find it somewhat odd that the "Aux Heat" indicator light was lit and yet the heat coming out of the vent was only "slightly warmer than the room temperature." If the Aux heat was on and functioning properly it should have been more than "slightly warmer." Actually, other than being in a defrost cycle (which really shouldn't last too long), there isn't any good reason for it being in Aux heat mode (when the outside temperature is 40-50 degrees as you state) unless you manually put it in Emergency Heat? Does your Vision Pro have the outdoor temperature sensor installed? Do you know what temperature (if any) the compressor lockout is set to?
Originally Posted by joechurch
The thermostat was set for 77 degrees in the morning... what is it set for during the previous (overnight) period? What was the weather like when you left for work? Rain? Sleet? Snow? Dry? I only ask because it could be your unit is frosting up in cool, wet weather and the defrost is not occurring frequently enough which causes the BTU output to drop to a point less than your house load requires. Did you happen to look at your outdoor unit during this period?
Lastly, was this a replacement unit for an existing heat pump? What size (tonnage) unit did it replace? Is your backup heat source electric resistance or fossil fuel?
True, but if the air handler is properly configured with the correct amount of electric resistance (or furnace BTUs if fossil fuel) for emergency heat then the house should have had no trouble maintaining and raising indoor temperature.
Originally Posted by lbf
the vision pro 8000 can be complicated for an individual who is not familiar with it
that being said, tech support at honeywell can walk you through the set-up parameters
it does sound like possibly other issues need to be dealt with on your system
you do like it toasty warm in there!
with the high temps you are requiring, expect a high light bill even when system is operating properly!