2019 40D12 Furnace Outlets

[chadwick101]

Just got a 2019 40D12. I'm wondering if I got a one off for how the furnace vents are run. There are two in the bedroom, one in the bathroom, and one in the kitchen under the oven. A fifth one leads into the underbelly to keep plumbing warm. The thermostat/temp sensor is located on stairs near the other control item.

This makes the bathroom very hot, the bedroom pretty hot, and takes forever to heat up the main part.

Is this how they're all built? Did I get a weird one?

Thanks,

Chad

[Nascon]

Replace the bed and bath registers with ones that can be closed.

[cavie]

Home depot and lowes

[rockfordroo]

No, you didn't get a weird one, that's how they build them.

Take Nascon's advice. But before you do, inspect the ducts and make sure (especially the bathroom) that they are all in good shape. Many people have reported pinched and/or otherwise obstructed ducts. Your bathroom one may be obstructed.

[rdolan5]

My 2017 Lacrosse had no air getting to the bathroom or master bedroom. I removed the air intake vent to the furnace to find two output holes on the furnace were unplugged without hoses going to them and only that silver duct tape crisscrossed over both holes. The heat and pressure from the furnace had blown the tape off one side and the tape was completely off the open holes. I cut two squares of SS plate, drilled holes in the corner, I applied silicone around both holes, and installed the plated over the holes with self tapping sheet metal screws. Now I have great airflow to both the bath and bedroom! Also note that my theater seating was not screwed to the floor yet 4 screws were laying in the carpet under the seating! So much for quality control!

[Larry-NC]

Originally Posted by Nascon

Replace the bed and bath registers with ones that can be closed.

I imagine you have the Suburban SF-series furnace. These are the most frequently installed models.

The installation manual in the "Library" strictly warns against doing that. If you do not have sufficient airflow across the firebox, it can get too hot. To protect the firebox from cracking or causing a fire, the gas shuts down although the blower continues to blow--unheated air. This cycling of warm and cool air blowing on you is very annoying.

In our trailer the furnace is very close to the bedroom. The bedroom is s few degrees warmer than the rest of the trailer. We simply turn the thermostat down a few degrees at night and up a few degrees in the morning.

[SeaDog]

On these rigs the air flow has allot to do with how the duct work was run. In my case I found short runs with double the duct needed. I solved the problem you are having by installing dampers at my furnace plenum to direct the air in a more even flow.

[chadwick101]

Thanks for all the ideas. I'm going to try to add some more lines off the furnace to open it up a bit.

I agree about blocking it off too much, that will cause all the issues listed above.

Thanks,

Chad

[Larry-NC]

Originally Posted by chadwick101

Thanks for all the ideas. I'm going to try to add some more lines off the furnace to open it up a bit.

I agree about blocking it off too much, that will cause all the issues listed above.

Thanks,

Chad

I have an inexpensive 7 meter USB borescope. If I recall correctly it cost around $10. One of these days I will run it through all the ductwork looking for excessively long or crushed ducts.

There are way too many reports where the duct apparently came in 10-12 foot lengths and rather than cut to needed length the installers just serpentined it into place.

Also in the case of rooftop air conditioning, no termination was installed. The duct empties into the roof area.