TXiceman wrote:

When the dealer refuses to help, you will need to invistae on your own. 7 deg F is way too much difference in temperature...4 deg F is too much. That sounds like a number some one pull out of his you-know-waht.

Ask them to show you this number in their Q-C procedures manual.

Ken

Jim,Rosemary, Sandy wrote:

What did the dealer check for? While all of the above suggestions are very good ones, it sounds like the dealer may have already done these and found nothing. It may be just a case of bad design. I highly doubt RV manufacturers think to test out their heat systems by measuring the air flow in each vent. Like any house, there are long runs of duct and short runs. The short runs closest to the furnace put out hotter air with more force. The longer runs put out less (thermal losses and loss of air pressure over the longer distance) That is why there are inline dampers on the ducts in homes, at least homes with basements. If I reduce the air flow in the ducts closest to the furnace, I should cause a increase in the heat and air flow available to the remaining ducts. So, while you do not want to cover the cold air return vents, you can close off the part of the the heat vents in the bedroom and hallway and see if the flow to the living room increases materially. I assume they are floor vents. I would just cut some pieces of sheet metal to cover up part of the openings. Once you get the system in balance, put the covers back on. Also, remember, hot air rises. So, all other things being equal, the elevated bedroom in a fiver is always the hottest room. That is why a second A/C unit in the bedroom is so common. The draft should not have anything to do with how much the furnace runs. It is the thermostat that determines that. My thermostat is in the ceiling in the kitchen area in the A/C unit. There is only one thermostat for both the A/C and the furnace. The furnace may run excessively simply because it colder in the room the thermostat is in.

nosticks wrote:

Similar problem in my Keystone Mountaineer. I had two ducts in the living room, fed by one run. The other run supplied the bathroom and the bedroom. The furnace is located in the kitchen under a cabinet and the cold air return on the kitchen side of the cabinet. The bathroom was a sauna, the bedroom a meat locker. Of the two living room ducts, the one furthest from the furnace was the strongest.

The first thing I did was remove the living room non-adjustable registers (vent outlets), and used a flashlight and inspection mirror to see if and duct work was collapsed. While doing so, ran a shop vac hose down each duct and picked up some loose construction debris (screws, saw dust etc.), none of which was significant enough to impede air flow. Duct work was fine.

Next, I removed the vents from the bathroom and bedroom performing the same inspection and cleaning. As mentioned, the bathroom was getting the lions share of the heat while the bedroom got very little. What I discovered was how the round supply duct was installed in the rectangular floor duct in the bathroom. The round duct protruded into the rectangular vent directly under the floor vent enough that when replacing the floor vent it channeled most all of the airflow straight up into the bathroom, leaving very little for the bedroom. I took tin snips and made a series of cuts in the round supply duct inside as it met the rectangular duct. I then folded over the snipped aluminum around the circumference making a smooth transition from round to rectangular. That balanced out the bath/bed room run.

I bought some 4 x 10 magnetic flexible vent covers at Wally World. I cut one in half lengthwise and placed it over the strongest vent in the living room, basically reducing the flow enough to balance the room.

Oh, and for the curious as to why not get adjustable vents to replace the original vents, they protrude too deep into the shallow rectangular duct runs and even when fully open will disturb the air balance.

nosticks wrote:

Similar problem in my Keystone Mountaineer. I had two ducts in the living room, fed by one run. The other run supplied the bathroom and the bedroom. The furnace is located in the kitchen under a cabinet and the cold air return on the kitchen side of the cabinet. The bathroom was a sauna, the bedroom a meat locker. Of the two living room ducts, the one furthest from the furnace was the strongest.

The first thing I did was remove the living room non-adjustable registers (vent outlets), and used a flashlight and inspection mirror to see if and duct work was collapsed. While doing so, ran a shop vac hose down each duct and picked up some loose construction debris (screws, saw dust etc.), none of which was significant enough to impede air flow. Duct work was fine.

Next, I removed the vents from the bathroom and bedroom performing the same inspection and cleaning. As mentioned, the bathroom was getting the lions share of the heat while the bedroom got very little. What I discovered was how the round supply duct was installed in the rectangular floor duct in the bathroom. The round duct protruded into the rectangular vent directly under the floor vent enough that when replacing the floor vent it channeled most all of the airflow straight up into the bathroom, leaving very little for the bedroom. I took tin snips and made a series of cuts in the round supply duct inside as it met the rectangular duct. I then folded over the snipped aluminum around the circumference making a smooth transition from round to rectangular. That balanced out the bath/bed room run.

I bought some 4 x 10 magnetic flexible vent covers at Wally World. I cut one in half lengthwise and placed it over the strongest vent in the living room, basically reducing the flow enough to balance the room.

Oh, and for the curious as to why not get adjustable vents to replace the original vents, they protrude too deep into the shallow rectangular duct runs and even when fully open will disturb the air balance.

RCMAN46 wrote:

I found a large hole (4 inch x 4 inch)in my duck that let air into the area under the floor and above the bellypan. I assume this was to keep the fresh water and waste tanks from freezing. But it did what you are having a problem with. I lowered my bellypan in that area and patched the hole. Solved my heat distribution problem.