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View Full Version : How to override heatpump & run gas furnace?


1dazed1
Dec 22, 2009, 02:22 PM
We would like to override our heatpump and have the gas furnace run instead. The heatpump has a setting to instruct it to run up to a certain outdoor temperature, and once it gets lower than that then the furnace kicks in. Our thermostat has an emergency heat setting that is supposed to activate the funace, but instead it just turns off the heatpump and the furnace blower fan runs, but the gas furnace doesn't engage. If the temperature gets below about 32 degrees then the gas furnce will come on. Any ideas on how we can override the heat pump? We honestly prefer the furnace to the electric heat pump.

wmproop
Dec 22, 2009, 05:51 PM
Kill the power /at breaker,, does the furnace only now come on when calling for heat?

When /if this works expect your heating cost to go up,, way up

Let us know

KISS
Dec 22, 2009, 06:50 PM
Wm:

This is a dual fuel set-up. Not a HP with electric back up. Way Way up doesn't apply.

Sounds like someone didn't install a dual-fuel system correctly.

With some Honeywell Vision Pro Stats that support dual fuel more options are available. Those stats require an outdoor sensor.

I'd suggest either pulling the disconnect outside. Usually you pull and turn the pull out upside down, or cut the power to the outside unit from the breaker box and see if it works.

Emergency heat should run the back-up heat, in your case gas without regard to outside temperature.

Bet a dual fuel kit or dual fuel thermostat with outdoor sensor wasn't installed.

1dazed1
Jan 22, 2010, 06:58 PM
Thanks for your reply... temps were cooler for several weeks, thus causing just the furnace to run and so we didn't have this problem. The past few days the temp around here has been around 40 and as a result the heat pump is being called to duty and totally failing at it's job.

We tried the suggestion, killing the power to the heat pump @ the breaker and on the until, but for some reason this just engages the fan to run and does not fire up the furnace. HELP, please??

KISS
Jan 22, 2010, 08:09 PM
This still applies:

Bet a dual fuel kit or dual fuel thermostat with outdoor sensor wasn't installed.

Take a look at the install instructions for the first two devices on this page: dual fuel - iaqsource.com (http://www.iaqsource.com/search.php?keywords=dual+fuel&submit_continue=Find)

In a dual fuel setup, the gas heat and the heat pump should not run at the same time.

There may be a dual fuel kit available for your furnace too.

For the thermostat opton to work, you have to put an outdoor sensor outside from the thermostat base.

You may need professional service for this is a complex setup.

I can't guarantee I can find anything, but do you have a make/model # of the HP?

Does the HP and the furnace run at the same time between two temperatures?