Heater burner won't ignite.

[klutchdust]

And of course at 7k feet and inside temperature was 39*. I checked the sail switch, it moves when the blower comes on and if i held it forward position and tried to turn on blower, the blower would not come on.I did remove the igniter and clean it, it does fire when asked to, the gas isn't turning on. I tried numerous times thinking the fuel wasn't getting to the unit but the water heater works and the 3 burner stove/ heater works fine. BTW, 3 burners lit with a window cracked heats up the garage a bit.
Anything else and to properly check the unit i have to remove it from the coach. Very little room between bed and wall to pull unit out. I see the fuel line needs to be disconnected and maybe a few screws into the floor holding it in position? Does the unit attach to the outside vents or just slide into them.

[MR.M]

Originally Posted by klutchdust

And of course at 7k feet and inside temperature was 39*. I checked the sail switch, it moves when the blower comes on and if i held it forward position and tried to turn on blower, the blower would not come on.I did remove the igniter and clean it, it does fire when asked to, the gas isn't turning on. I tried numerous times thinking the fuel wasn't getting to the unit but the water heater works and the 3 burner stove/ heater works fine. BTW, 3 burners lit with a window cracked heats up the garage a bit.
Anything else and to properly check the unit i have to remove it from the coach. Very little room between bed and wall to pull unit out. I see the fuel line needs to be disconnected and maybe a few screws into the floor holding it in position? Does the unit attach to the outside vents or just slide into them.

Surburban furnace should just be one screw to remove the heat exchanger and blower assy . need to check continuity through sail switch . also there is a hi limit in the back side attached to the heat exchanger . sometime continuity can be sketchy through the hi-limit depending on which one is in there . or if you can hear it try to lite but no gas flow could be board . this is just a start of places to start

[klutchdust]

Using a troubleshooting check list I found on the web I went from one component to the next . I got to the one where if 12 volts was not coming out of the board, replace it. The board is no longer available from Suburban but a company called dinosaur electronics has one. The unit is in a '16 trailer and no board?
Tomorrow we shall see if it works. I have the unit on a test bench ready to fire up.
I posted before about the ducting being crushed under the shower during the build of the trailer. With the furnace removed I was able to route the duct a bit better. The duct going under the shower to the garage cannot be accessed.Heat up front and in bathroom will be fine.

[klutchdust]

So here is what I found. The control board was intermittent. Sometimes there was 12 volts coming out of it and sometimes not. After changing the board the furnace still would not light so I changed the gas valve. Bingo!. I also installed a new gasket around the igniter and replaced the igniter as well. So 99 for the board from Dinosaur, 45 for the gas valve ( I purchased the one stating "used" and they said there may be some cosmetic imperfections, there was, the original packaging was torn) and 11 dollars for the igniter and 10 for new gaskets. $165 and my furnace is in top shape. New one is around 650 plus.
I found a RV mechanic on U tube that helped me a lot. "My RV Works. " Check him out.

[sdelam]

Thanks for updating. Always good to see the resolutions.