Weak bedroom furnace heat delivery

[MandN]

2019 Flying Cloud furnace duct to bedroom has a split to provide heat (via a 2 inch duct) to the basement, Has anyone moved that2 inch duct to the galley duct to try to get better flow to bedroom? Did it work? Pros and cons?

[RamTruck]

Good day!

For what it's worth, I have a 27' front bedroom Globetrotter and upon delivery noticed very low air flow in the bedroom.

I recommend inspecting the furnace ducts before modifying anything.

As the pictures show, when I removed the distribution panel, the charger/converter was freely sitting on top of the ducts. The bottom duct was very constricted.

After disconnecting the ductwork and rerouting above the charger/converter, the air flow in the bedroom increased significantly.

Best!

[uraljohn]

We have a 2019 FC 25 RBT. In order to increase the flow of heat from the bedroom duct I did the following.
Closed off half of the duct that is just inside the entrance door on the left. Pop off the duct cover and put some good old "Duct" tape over the back side of vent cover. Pop it back on. Presto chango more heat to the back of the trailer. This also keeps you from cooking when sitting at the table when furnace comes on. After I figured this works and there was no ill effects on the furnace operation I went to the RV store and bought an adjustable vent cover to fine tune the air delivery to the back of the trailer. This has worked well for 2 years.

[MandN]

Thanks for your responses I double checked to make sure that bedroom duct was not pinched/obstructed. Dampening the under the table outlet is a great idea and helped significantly!

[TNOutback]

We have a new 2023 FC 25 RBT and there is barely any air coming out of the bedroom duct. On my first test of the system with the outside temp of 55 degrees, the bedroom and dinette area measured with room thermometers were both showing 61. Setting the furnace thermostat to 68 and running the furnace for 45 minutes, the dinette area temp was 73 and the bedroom temp was still 61 degrees - no change.

The furnace installation manual for the model in our coach requires a minimum of 3 vent ducts with 220 CFM. I don’t think partially blocking the dinette area vent is technically allowed and could overheat the furnace.

[TNOutback]

UPDATE: I performed a little experiment to see if I could force additional air to the rear vent. Outside temp was 40; inside temp was 42! I put some aluminum foil over ~30-40% of the front vent on the dinette end and ran the furnace, setting the thermostat at 68. I could immediately tell there was more airflow in the bedroom area and the temperature was actually rising in the bedroom. However, about 10 minutes of running and the furnace cuts off, leaving just the fan running. Cabin temp still 20 degrees from the set point. After a few minutes, the furnace kicks back on, runs several minutes and turns off. While blocking the dinette vent closest to the furnace helped in the bedroom, the furnace was apparently tripping off on temperature limit. I removed the aluminum foil and restarted the furnace and it has run continuously since with no stops. So a failed experiment . . .

[GCinSC2]

Originally Posted by TNOutback

UPDATE: However, about 10 minutes of running and the furnace cuts off, leaving just the fan running. Cabin temp still 20 degrees from the set point. After a few minutes, the furnace kicks back on, runs several minutes and turns off. While blocking the dinette vent closest to the furnace helped in the bedroom, the furnace was apparently tripping off on temperature limit. I removed the aluminum foil and restarted the furnace and it has run continuously since with no stops. So a failed experiment . . .

I'd agree with your conclusion, the furnace overheated and shut itself down, a safety feature. Hi limit switch did it's job.

[MandN]

The solution above has worked very well for last 3 years. If covering the duct under table duct 30% caused the furnace to overheat I think your ducts are pinched or obstructed. For example my bedroom duct was too long and was bunched up and constricted at the vent out, I had to straighten/shorten then reattach.

[RWKais]

I. too, had noticed low furnace air flow to the bedroom furnace outlet. Hot air flowing from the two outlets under the sink area blasts out. The two issues that this created was: 1. The dinette area gets very warm before the thermostat, located by the bed, can reach the desired temperature. 2. If the curtain is closed, the low airflow to the bedroom can't catch up. After reading posts online, I inspected the duct work under the wardrobe (by the water pump) and discover two 90 degree bends from the furnace to the outlet (See attached photo). This definitely restricts airflow. An easy fix was to straighten out the duct to the outlet (See second photo). The difference in airflow was significant. Before straightening, you had to have your hand almost on the outlet to feel air flow. After the modification you can feel airflow almost 3 feet from the outlet. I'll report impact to living conditions next time I take a cold weather trip. My expectation is the bed area will get warmer faster resulting in the thermostat registering more balanced heating.