Have a new Coachman Mirada 32SS with front and rear heat pumps. There is only one propane furnace in the unit. It is connected as the alternate source to the front unit. My question is, how does the rear heat pump operate when the thermostat is calling for the gas heat? The thermostat in the rear is the same as the front. Thanks for the feedback.
Front and Rear Heat Pumps only one Gas Furnace
- Thread starter lmalmen
- Start date
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Gary RV_Wizard
Site Team
Please tell us the make/model of thermostat as well as the heat pump make & model. Operation varies, so it helps to know the specifics.
Generally, neither heat pump should operate if the thermostat is set for gas furnace heat. The heat pump may request assistance from the alternate source if it cannot keep up with demand, but when the thermostat is set to Furnace or Gas Heat, it usually means only that source.
Generally, neither heat pump should operate if the thermostat is set for gas furnace heat. The heat pump may request assistance from the alternate source if it cannot keep up with demand, but when the thermostat is set to Furnace or Gas Heat, it usually means only that source.
Back2PA
Well-known member
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- Jul 26, 2015
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I have two heat pumps and one furnace, but one thermostat. Typically when it gets too cold for heat pumps (or when you're not plugged in) you switch to furnace mode. Sometimes it happens automatically. If yours isn't automatic you'd shutoff the rear and switch the front to furnace. My heat pumps will run to about 32 (it was 34 last night and I am using them now). Some only make it down to about 40
Gary RV_Wizard
Site Team
Part of the question is whether the thermostat is single zone or two-zone. For practical purposes, dual zones acts like two separate thermostats.
Gary RV_Wizard
Site Team
Shared ducts are common in all but the high end RVs, but they still often have two (or even three) zones. Most of the heated or cooled air comes out of the closest duct vents, so separate zone controls are reasonably effective. However, only one of the zones may be wired to call for aux heat (gas furnace).
You haven't advised us of the thermostat brand/model or whether the thermostat has separate settings for gas furnace only vs heat pump. It's difficult to be helpful without that info.
You haven't advised us of the thermostat brand/model or whether the thermostat has separate settings for gas furnace only vs heat pump. It's difficult to be helpful without that info.
Bobtop46
Well-known member
Shared ducts and zones generally apply to the Heat pumps and ACs and are usually in the ceiling. Furnace ducts are usually in the floor and cover the whole RV. Your rig is wired so that only one T-stat controls that system. As others have mentioned, once the heat pumps can't keep up the front T-stat will call for the furnace to help out. Once this happens you are better off manually shutting off both heat pumps and put the front T-stat on furnace or gas heat.
Assuming you have two single zone thermostats (one with furnace) and not one dual zone thermostat, here is what we experienced in our last 5er with two heat pumps and one furnace:
On the thermostat with the furnace, when the delta between thermostat set temperature and actual temperature reached about 5 degrees (not keeping up), the thermostat would shut OFF the heat pump and turn ON the furnace. Swell enough. The problem was with the other thermostat without the furnace. If temps dropped below 35 or 40 the heat pump compressor would shut down, but the fan would stay running! I would wake up with warm air coming up from the floor, and cold air blowing on me from the ceiling. Very annoying.
I learned to use only the heat pump with the furnace if I anticipated temps to get below 40 in the night
These are what I had (one said cool and heat, the other cool and elec heat/gas heat):
On the thermostat with the furnace, when the delta between thermostat set temperature and actual temperature reached about 5 degrees (not keeping up), the thermostat would shut OFF the heat pump and turn ON the furnace. Swell enough. The problem was with the other thermostat without the furnace. If temps dropped below 35 or 40 the heat pump compressor would shut down, but the fan would stay running! I would wake up with warm air coming up from the floor, and cold air blowing on me from the ceiling. Very annoying.
I learned to use only the heat pump with the furnace if I anticipated temps to get below 40 in the night
These are what I had (one said cool and heat, the other cool and elec heat/gas heat):
