Thursday, June 1, 2023


How can I distribute the heat more evenly in my 5th wheel?

Dear Dave,
is there a way to force more heat to the living area in my 5th wheel? The bedroom is 10-15 degrees (approximately) warmer than the living area. —Randy, 2022 Flagstaff 8529RLS

Dear Randy,
It looks as though your Flagstaff is a 5th wheel with the step-up bedroom. I cannot see the vents in the bedroom. However, I do see one incorporated into the step going up to the bedroom and a few others. Those make me believe you have the corrugated hoses I call “elephant trunks” rather than a straight plenum. [From Merriam-Webster: plenum: an air-filled space in a structure, especially one that receives air from a blower for distribution (as in a ventilation system).]


Get an anemometer

The first thing I would do is get a anemometer and check air flow and temperature coming from all the vents in your rig. If the bedroom is 10-15 degrees warmer, I would believe it is closest to the heating unit. This can help tell if there is a deficiency in the actual furnace run to the living area, an airflow issue, or poor insulation in the living area. You can get an inexpensive one on Amazon here.

If you have a similar temperature and airflow coming out of the bedroom vents as you do in the steps or other living room vents, it could be poor insulation either in the floor, cabinets, or windows. Your bedroom most likely has a carpet and pad, the mattress and all blankets/comforters, and is typically a smaller space. Your living room most likely has some type of vinyl or plank flooring and is wide open, which means less insulation. Take a look underneath in the compartments to see if the plenum is exposed. If the compartment is not heated, it will lose efficiency.

Check for cause of low airflow

If it is low airflow, then look to see if the hose is crimped or if there is a gap in a connection. Sometimes those hoses are looped and turned in a 90-degree angle zig-zagging around things, and it’s almost impossible to get good air flow. If this is the case, see if there is a way to straighten the hose and reduce the angles.

You could try covering the bedroom vent slightly to direct more airflow back to the living area but you need to be careful you do not block too much airflow. The fan inside your furnace moves the hot air over the burner and past a sail switch to the hoses and vents. The air raises the sail switch which creates a closed circuit sending 12-volt power to the module board telling it there is sufficient airflow. If the airflow is reduced by shutting too many vents or having rugs over the vents, the switch drops and shuts the furnace off. So you might want to try just one and see if it helps the temperature and doesn’t limit the airflow.

Try a register booster fan

Another option would be to get a register booster fan that would help draw more air from that run. Depending on where the register is and if it is flat on the floor or vertical in a cabinet, most home improvement stores have a version that can help boost the air. Here is one that is available on Amazon that just sits on an existing floor mount register. I used one of these in a house that had a cold room at the farthest end of the furnace run and it worked great. It does need 120-volt power. There are models that will fit flush in the floor or wall if you can match the size of the register cutout. Here is the link.

Or you might consider a standalone catalytic heater

After all this, you might want to consider supplementing the living area with a standalone catalytic heater such as the Olympian. This is a popular heater with boondockers as they can turn the furnace down to a lower temperature at night and just heat the bedroom, thus saving LP and 12-volt power. You can do the same by turning down the temp and supplementing the living area. They are very safe, with little or no dangerous gas. They can be portable with a small screw-in tank, or wall-mounted and plumbed into an existing LP system. No fan, no flame, and adjustable to various temperature settings. You can find the Wave-3 model here.

Plus, keep in mind that warm air rises and since your bedroom is the highest point of your RV, that air will rise to the bedroom. Keep the door closed and get a few fans to circulate the air inside your rig. Most RVs have very poor HVAC circulation.

 You might also enjoy this from Dave 

When RV heat is on, cabinets and counters get hot. Why?

Dear Dave,
The drawers and countertops in/on the cabinet that houses the heater for the camper get very warm when the RV heater runs. Is this normal or is there a blockage somewhere that is causing this? We leave the drawers open when the heater is on. —Jeff, Highland Ridge Open Range Light 275RLS

Read Dave’s answer.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here


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Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.


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1 month ago

What I did was remove the floor grills in the bathroom and bedroom and cover them 50% underneath with tin foil.

2 months ago

A small fan pointing in the direction of cooler area works. If possible, mount it high on a wall. Warm air naturally rises. The fan will distribute the warm air. Just don’t point it towards the thermostat.

Jim Johnson
2 months ago

Fully agree about rising heat. Can you run a A/C unit in fan only mode separate from the furnace? Some 5th wheel units have a vaulted ceiling in the living area – and some of those come with a residential ceiling fan. Is there a blank electric wall plate on the ceiling to add a ceiling fan?

Bob p
2 months ago

I would say your last comment is probably the problem, I have never seen a bedroom door going to the room. It’s the nature of the 5th wheel. I have always thought the front upper living room was a great idea as the temperature could be set for comfort there and a lower level bedroom would naturally stay slightly cooler. I would suggest hanging some kind of curtain in the hallway going to the bedroom to help prevent the natural heat rising to the bedroom.

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