HP AUX HEAT does not shut off until Tstat set point

[riderman]

I just finished a complete geothermal install. This issue is kicking my butt. This system has a single stage compressor with 15 K of thermal B/U heat.

The Tstat is a WF model TP32U03 3 stage heat 2 stage cool.

My question is: The aux heat turns on at 3 degrees above room temp. The aux heat will not turn off until the tstat room temp setpoint is satisfied and the heat pump shuts off. Is this aux heat "turn off" a function of the tstat or the WSHP mother board? I tried programming the tstat, I can get the aux heat "turn on" temp to be delayed until 7 degrees above room temp vice 3 degrees, but the aux heat still stays turned ON until the tstat\room temperature is satisfied. Shouldnt the aux heat turn off within 2 degrees above the tstat (room) temp? Is this normal operation for some tstats?

On another note, on this single stage compressor system, Y2 heating just bumps up the speed of the X13 ECM motor a little bit. What is the purpose\gain of that? I mean, if I'm losing heat in the structure calling Y1, why would I want to add AHU cfm without additional heat?

Thanks

[BaldLoonie]

If the geo is single stage, Y2 shouldn't be hooked up. I suppose it is possible that the geo uses the same board for both single stage and 2 stage where high needs a tad more airflow.

I have heard of stats that can be set to leave backup on until both stages are satisfied. Rare. But only thing I can think of besides a defective stat. Look through your advanced setup options.

[pacnw]

Not sure if this applies, but;

some stats have a feature that will allow it to "... finish on high fire/stage". I take this to mean that it will ramp down instead of continuing on max. This is a stat setting.

as for the fan, on product we install(our installers and many techs don't get this) if you have a single stage unit on a two stage board and Y1/Y2 are connected(by jumper or internal) then it runs Y2 blower speed. you MAY, like on our product, be able to separate Y1 & Y2 and connect to Y1 only and get its speed. This is on the unit board for us.

[Tommy1010]

the possiblity that a little tweekage in the tstats installer set-up mode may help

[Brent Ridley]

Check the link below. Page 5 under "smart heating". If "on", It states once the aux heat is energized, the aux heat will stay energized until thermostat is satisfied regardless of demand/differential.

http://www.waterfurnace.com/thermostats/TP32U03-5.pdf

[riderman]

Check the link below. Page 5 under "smart heating". If "on", It states once the aux heat is energized, the aux heat will stay energized until thermostat is satisfied regardless of demand/differential.

http://www.waterfurnace.com/thermostats/TP32U03-5.pdf

Thank you all for the responces. Yes, this is set to "off". I called WF, they said this is the normal function of this Tstat, keep aux heat on until set temp is satisfied.

[BaldLoonie]

I sure wouldn't want that. Can you turn it so backup only runs when needed? Will save you juice!

[54regcab]

I sure wouldn't want that. Can you turn it so backup only runs when needed? Will save you juice!

+1 !!!

[Tommy1010]

Thank you all for the responces. Yes, this is set to "off". I called WF, they said this is the normal function of this Tstat, keep aux heat on until set temp is satisfied.

hmmm, sounds a little sketchy

[tim79]

Its your energy to waste, if wf says its normal I would go with the company. We use to have things called anticipators when i was a kid, wait I still am:]