Operating heating system

[Rogerfish]

With winter coming I am trying to figure how to best operate the heating system in my new RW. When the outside temp gets down around 40, the heat pump starts to cycle on and off and the fan keeps running. When the pump cycles off and on it gets louder and vibrates a little. Finally, it cycles off but the fan continues to run blowing cold air out the ceiling vents. After a few minutes the gas furnace turns on while the heat pump fan still blows cool air out the ceiling vents. When the desired temp is achieved, both the gas furnace and heat pump fan turn off. Does the heat pump fan stay on to circulate the warm air from the furnace? Are the 2 systems designed to work together or when the temp gets down near 40, are you supposed to go to your wall thermostat and slide the switch from electric to gas so only the gas furnace is on?

Also, I have noticed that the warm air coming out the floor vents is not as forceful as is was in our previous Big Country. Wondering if we will stay warm when the outside temp gets down to 0 or below. Anybody done that?

[atom ant]

Originally Posted by Rogerfish

When the pump cycles off and on it gets louder and vibrates a little. Finally, it cycles off but the fan continues to run blowing cold air out the ceiling vents.

Man am I glad you said that! Last time out the temp dropped in the night and that heat pump vibrating and getting louder actually woke me straight out of bed and I thought it broke! It did work fine the next night, but not what I expected when the temp dropped below 40. I knew they shut down, but not with a bang.

That night I was only using the 2nd heat pump which isn't tied to the furnace thermostat, so I didn't get furnace back up (that thermostat was off). My fan did continue to blow cold air, just to make sure I was aggravated, not just inconvenienced

I'll be curious what you hear - if the primary heat pump/furnace coordinates better, I'll use it instead. Otherwise I guess I'll just watch the weather report to determine which system I'll use overnight.

[markw]

At about 40 outside the heat pump, pretty much stops making heat. When the inside temps reach 3-5 degrees below the set temp the furnace comes on. When I know it will get that cold I switch to gas before going to bed.

Mark

[atom ant]

Mark, does the heat pump continue to blow once the furnace is running or does it eventually shut down?

[NW Snowbirds]

[QUOTE=

Also, I have noticed that the warm air coming out the floor vents is not as forceful as is was in our previous Big Country. Wondering if we will stay warm when the outside temp gets down to 0 or below. Anybody done that?[/QUOTE]

It's quite likely your hot air duct manifold is hanging loose from the furnace. Many of us have had this problem. The manifold is/was attached with metallic duct tape which looses its adhesion. Much of the hot air then does a great job of heating the "crawl space" behind the wall in the basement. You need to take down the black wall to fix it. I screwed the manifold back in place and also used sealant around the joint. The furnace also uses the crawl space as a return air duct so you are short circuiting the heated air from the furnace with the return air from the coach.

[Rogerfish]

Where is the air duct manifold on the furnace? What does it look like? Is it inside the furnace or outside?

[NW Snowbirds]

The manifold is outside the furnace and has three flex circular ducts discharging from it on mine. The sheet metal manifold tapes to the furnace discharge plenum. My friend has a 36RL which had the same problem.

[markw]

Originally Posted by atom ant

Mark, does the heat pump continue to blow once the furnace is running or does it eventually shut down?

I believe that it stays on as long as the t-stat calls for heat.Once the temp comes up with help from the furnace, everything shuts down until it calls for heat again. That's why when you try to bring the temp up with the HP and the trailer is cold, you have to stay within 3 degrees at a time. Otherwise the furnace comes on.

Mark

[atom ant]

So not as efficient as I thought. Sounds like you have to pre-plan a little and select wich one you want.

[Tomkidder]

The reason the heat pump shuts down in the unit is because it is a 110v unit. If it was a 220 unit when the temp outside gets below 40* the unit will stop and run the R22 in reverse to warm the outside coils for a minute or so to "defrost" the outside coils. Knowing this in order to have the ability to do this requires a 220v pump because it has a lot of head pressure to reverse that requires a fair amount of torque. The RV type barely has enough torque at a 15-17 amp draw to pump R22.

[Shane Wood]

I use the front heat pump set to 65 and the rear one set on air tied in to the furnace at 78. This way we have air when it warms during the day and heat at night.The front heat pump works good until 30 degrees. We are averaging 76 during the day and 48 at night. I have had both units set on heat pump down to 30 and the furnace never kicked in nor have they started blowing cold air

[travelin' texans]

The furnace ducts are shiny silver hoses running like a can of worms behind the basement wall & it's a 99.99% chance the pair going to the bedroom register have fallen down. Take the wall down & look up to your left, as mentioned above seal it & add a few screws & should improve your furnace efficiency 100%. Those ducts have been falling off since RW #1 came off the line, wouldn't know why they would start attaching the better now.

[atom ant]

Oh I don't know - my house heat pump shuts down at <40 as well.

[travelin' texans]

Oh! If you can find some one that's 3' tall with 6' long arms that can operate a drill driver it will make the job a snap, if not a contortionist would work, otherwise tell the DW the air may turn blue once you start that project.
Don't get me wrong it's an easy fix just a tough spot for a well rounded guy like me.

[Tomkidder]

Originally Posted by travelin' texans

The furnace ducts are shiny silver hoses running like a can of worms behind the basement wall & it's a 99.99% chance the pair going to the bedroom register have fallen down. Take the wall down & look up to your left, as mentioned above seal it & add a few screws & should improve your furnace efficiency 100%. Those ducts have been falling off since RW #1 came off the line, wouldn't know why they would start attaching the better now.

Go to Home Depot or lowes and get a piece of 1/2" X 1/2" aluminum v-bar and some self tapping screws at place to v-bar between the to duct hoses leaving to the bedroom and drill into the aluminum floor joists. Then use real aluminum ducting tape and seal the hoses to the box. I will see if I can get a picture for you.

[markw]

Even houses heated with a HP need a backup source. They get heat by taking it out of the outside air. When the temp gets down to 40 or so, there isn't enough to extract.

Mark

[rob_fla]

The efficiency of a Heat Pump will continue to decrease as the outside temperature gets colder.
When going to bed at night if the overnight temps are going to be in the mid 30s or lower we just switch to propane heat, leave our small electric space heaters on to supplement the propane and stay warm and toasty.

[Rosey]

While we're on the subject of the heat pump, I'd like to keep mine on while in storage this winter on my property as added insurance to avoid any potential freezing issues. Would my 15 amp service be sufficient to run 1 heat pump ? Thoughts ?

[Dave&Ginny]

I don't know if I would risk it since you wouldn't be with the unit all the time. Depending on your electrical panel, it wouldn't be hard to wire up a 30 amp plug. A 30 amp would be ideal for one unit running it like I said it's an easy process with 10 gauge wire.

[Tomkidder]

I don't think 15 amp service will handle the start up on the motor. Even in the coach each A/C unit is serviced by a 20 amp breaker on each side of the 220 legs coming in. The short answer I don't think so.