Heat Pump Question

[Ljsydney]

Hi,

Arrived in Flagstaff yesterday from Scottsdale…got down to 21 last night (!)…big change for me and my first time camping in cold weather.

From early evening until about 9pm I heated the trailer using a ceramic heater as I'm plugged in to power. Around 9pm, in anticipation of a cold night, I disconnected my water hose (I don't have a heated or insulated hose) and turned on the furnace…set the temp at 50 to keep the trailer warm enough so that pipes wouldn't freeze etc.

When I turned it on, the heat pump went on but the furnace didn't. I kept an eye on it for awhile and later the furnace did come on (with the HP still running). I was worried that since the HP is not ducted, the pipes I was trying to keep from freezing, were not getting enough heat so I turned the temperature up to 65…both the HP and furnace were running.

Morning now and everything appears to be fine…temperature will rise above freezing in the next hour or so. It seems as if the HP ran all night without ceasing and the furnace ran intermittently but was sufficient to do the task at hand.

My understanding was that the HP would switch off automatically once the temp went down to below 40 as it's not very effective at that point and the furnace would take over. Does anyone know why it didn't switch off? And is there a way to override the HP when I want to run the furnace (only) even when I'm plugged in. Note my controller mode is set to "FURN", not "HP".

Any insight or other comments most welcome…

Thanks in advance.

[Jammer]

Well you can always pull the breaker for the air conditioner.

Not sure how the latest ccc is supposed to work.

[urnmor]

More questions then answers for you. Do you have a multi zone unit? Ours is a single zone. Not sure your climate control panel is the same as ours for a single zone unit but if you go to the mode and select furnace the HP should shut off.

Also coud it be the fan that was running and not the HP. I ask only because when I set the control panel to the furnace our HP does not run.

[Ljsydney]

Originally Posted by urnmor

More questions then answers for you. Do you have a multi zone unit? Ours is a single zone. Not sure your climate control panel is the same as ours for a single zone unit but if you go to the mode and select furnace the HP should shut off.

Also coud it be the fan that was running and not the HP. I ask only because when I set the control panel to the furnace our HP does not run.

I don't believe it's multi zone…CCC display currently showing "zone 1"…and when I depress the "zone" button on the CCC there are no additional zones to toggle through.

It sounds like we have the same controller….and yes, I've selected "FURN" and both the HP and FURN run. That only happens when I'm plugged in to shore power. If I'm off shore power, then it's just the furnace that runs…as it should.

[lewster]

Originally Posted by Ljsydney

I don't believe it's multi zone…CCC display currently showing "zone 1"…and when I depress the "zone" button on the CCC there are no additional zones to toggle through.

It sounds like we have the same controller….and yes, I've selected "FURN" and both the HP and FURN run. That only happens when I'm plugged in to shore power. If I'm off shore power, then it's just the furnace that runs…as it should.

New Dometic CCC-II and single zone thermostats are programmed to operate the roof unit fan, but not the compressor whenever the gas furnace is on. You can avoid this by selecting 'auto' for a fan setting, as this will allow for the operation of the furnace ONLY.

Dometic dod this to help circulate the hot air rising to the ceiling from your floor ducts back thru out the RV. Most of my clients prefer the furnace-only option.

[Ljsydney]

Originally Posted by lewster

New Dometic CCC-II and single zone thermostats are programmed to operate the roof unit fan, but not the compressor whenever the gas furnace is on. You can avoid this by selecting 'auto' for a fan setting, as this will allow for the operation of the furnace ONLY.

Dometic dod this to help circulate the hot air rising to the ceiling from your floor ducts back thru out the RV. Most of my clients prefer the furnace-only option.

Ahhh…I think that's it…just did a test and the fan (thought it was the HP) cut out so will see how it goes when it gets cold tonight…

Thanks all for your advice!