Reburbing an old Suburban NT30MA furnace

[wacnstac]

Right now I got spark but no flame. Plan on replacing the board for sure. Just don't like the "lock out" on the old board. Is this board (Marksrv.com fan 50 plus page) a direct drop in replacement. Also the furnace always stoped blowing and then would restart the blow for a few short bursts after it go done. I assume this would be the limit switch and I assume the 0230496 would be the replacement for that...

Before I get too crazy on replacement parts is there a way I can test the gas solenoid? Can I just put 12 volts directly across it and see if I can hear it click?

[Janets Husband]

Originally Posted by wacnstac

Right now I got spark but no flame. Plan on replacing the board for sure. Just don't like the "lock out" on the old board. Is this board (Marksrv.com fan 50 plus page) a direct drop in replacement. Also the furnace always stoped blowing and then would restart the blow for a few short bursts after it go done. I assume this would be the limit switch and I assume the 0230496 would be the replacement for that...

Before I get too crazy on replacement parts is there a way I can test the gas solenoid? Can I just put 12 volts directly across it and see if I can hear it click?

One thing to check before you put any money into this unit, was it part of the recall. Some older units had the exhaust connection between the heater and the outside duct connected with a rubber bushing. These bushings failed and allowed carbon monoxide to leak into the trailer. Please check this out first. I don't know if they even have a replacement available for them.
The newer heaters have a metal slip connection which is a lot more secure. Newer heaters also take much less current to run the fans 3.5 amps vs. 7 amps. Take a look at them before plunking down cash on an older unit.

[wacnstac]

Mine was not part of the recall and is connected to the outside duct with a metal slip connection. I cannot buy a direct replacement for this furnace or I would.

Now back to refurbing this one....

By the way I check the gas solenoid by putting 12V across it and I get a nice solid click.

[wacnstac]

Here is a picture of the furnace control board that I want to replace:

[wacnstac]

Well, I found one problem already. It seems that my limit switch that is supposed to be normally closed is open all the time. That definitely needs replacing and while I'm at it, I want to replace the sail switch, the fan switch, and the main control board (to avoid waking up to a dead battery and no heat due to lockout).

[wacnstac]

Can anyone tell me if the new Dinosaur Electronics circuit board would be compatible with my furnace and exactly how I utilize it to control the fan? Would I bypass the fan control switch currently on the system?

[Ganglin]

You might want to try calling these folks - looks like their boards are "universal"... ?

Marksrv.com Suburban RV furnace parts