Furnace is running all the time heat pump is off due to cold. Should the furnace be running all the time? Is this normal?

It sound like the limit switch is shutting off and not coming back in to play .

Turn the thermostats fan position to Auto instead of ON. If it already is in Auto, then there is a fan relay stuck in the board.

First, check the drainline from the furnace. You have a 90% gas fired furnace. Where 80% furnace has 1 heat exchanger, yours has 2 heat exchangers. And the second heat exchanger will cool the exhaust enough, that it ends up below the dew point, and your furnace outlet/exhaust will condensate. This drain is probably stopped up. Now, I've installed and service many of these systems and I've only seen the piping at the roof you described once. And that was when the roofers replaced the roof, damaged the furnace flue pipe, and tried to repair it themselves. Normally, and this may not apply to yours, we tie in the exhaust/supply lines about 2-3 ft. above the furnace. Then 1 pipe goes through the roof. Thus 1 pipe is a kit that has an inner liner & outer pipe(2 pipes in 1). Now I'm not sure if this is a problem or normal for your system, but it may be worth looking into. You should be able to find it in the installation manual, or call a local parts house that sells your brand, or as your tech. And if it's just your drain, forget all about the piping I mentioned. Hope this helps!

do you have an automatic change over thermostat? this would switch it from heating to cooling.

At tstat press options. Press installer setup. Yes, you are qualified. System settings, non heat pump. Gas/ oil heat. Save changes. That should do it with no wiring changes.

If you need further help, reach me via phone at https://www.6ya.com/expert/thomas_092728000e6acb79

Make sure filters are clean . if they are stopped up the unit will over heat. Lets start there. Russ

An explanation....

When in the heating mode, all heat pumps are dependent upon the outdoor conditions to remove heat energy from the environment and turn it into useful heat for your dwelling.

Heat pumps operate more effectively in temperate climates (as in southern states) and if it's as cold as you say, then the furnace is coming on to add auxiliary heat to the space to make up for the lack of heat being supplied by the heat pump. This is normal.

Some heat pump systems are or can be equipped with a control known as a "low ambient cut out" and/or "motor master" that prevents the heat pump compressor from operating and slows or stops the condensing unit fan when it's too cold and risking potential compressor damage. When it's in the single digits outside, a heat pump is only marginally effective. and usually requires auxiliary heat (your furnace).

If the furnace keeps operating when it's in the 30s or 40s, you may want to have the system examined by a competent service technician. As always, the outdoor condensing unit should be kept clean and the furnace filter should be changed no less than monthly, unless you have an electronic air filter.

Hi,
A couple of things... First your furnace should be 2nd stage on a 2 stage thermostat and if the heat pump don't keep up your furnace should be coming on anyway...If you get a Honeywell Vision Pro 8000 series thermostat for 2 stage heat pump operation and an outdoor sensor, you can have the thermostat shut down the heat pump and start the furnace at what ever temperature you decide...

Secondly, you have a problem with the defrost cycle on your heat pump(s) If they are frosting up that bad at 40 degrees than the defrost is not working on them. If they are hookup up right, every fours hours or so they will go into A/C mode and heat the oudoor coil up to melt the ice off of them. The furnace should be heating while that is happening. Sounds like they really don't know what they are doing when it comes to heat pumps...

I hope that this will help you to solve your problem!

Thanks for using Fixya!!

Heatman101

If you have a Gas furnace in the Attic then the answer is yes. The outside condenser will not run if in fact you have a gas furnace.

It is normal. Your house has to go down a couple more degrees because the heat pump is not working. You can solve this by rewirng you thermostat. Take off the wire that goes to Y and tape off. Then take the wires that are marked w and e or w1 and put the wires to yellow. Do not run ac with it wired like this. If you need more information please post me back