Suburban furcance prob lem

[Dr_Quick]

My furnace will light and run for about 5 seconds, then quit for maybe 30 seconds and try to light again. It does this 3 times then shuts down. You can turn off thermostat and it will cycle and keep on doing the same thing again.
Have you had this problem and want what was done to solve problem and get furnace running again
Thanks

Additional information: Trailer is only just over 2 years old, so furnace is out of warranty. In that 2 years we have camped say 65 days and maybe used the furnace 15 or 20 nights.
I did one test of the furnace where I turned on all three stove burners then turned on the furnace to see if gas pressure would drop. but when furnace lit for a few seconds, gas flames on stove never changed. So I do not think it is a gas or regulator problem.

[TUCQUALA]

Got a compressed air source?? If so, blow out the inlet and outlet. May not help, but did with mine!! Dust and dirt possibly on the photo sensor. Not had a problem since doing this this spring. Doesn't cost anything to try!!!!

[rrupert]

Before doing anything do as I did and obtain a copy of the service manual for your furnace and follow the the diagnostic procedure. That's how I tracked my problem down to low gas pressure.

[lakeside013104]

Old-Biscuit wrote:

SidecarFlip wrote:
Mr. Biscuit will be along and diagnose your issue and tell you the proper procedure to fix it.

'wkamper' done hit it on the head.

Circuit board not seeing the flame lit miliamp signal so it drops the DC to gas valve. 3X then 'locks out'

You two guys are priceless. So much valid information from the pair. You should write a book of knowledge. You could title it: Sidebiscuit Information Group, Biscarr Info, or maybe OldSidecarrBiscuits Words of Wisdom........


Keep it coming, Gentlemen.

Lakeside

[SidecarFlip]

My suggestion instead of listening to all the phooey is follow Mr. Biscit's advice. he knows.

You follow everyone's suggestions and you'll be replacing every part. No point in that.

[Pauljdav]

troubledwaters wrote:

Pauljdav wrote:
Need to replace the main board with a dinosaur fans 50 plus pins. All three of my rv s needed this upgrade.

Replacing the main board won't do a thing if its the flame proofer causing the problem.

I very high doubt it is the flame proofer.
These original main boards have cheap soldering that causes these, and many other symptoms.

[troubledwaters]

Pauljdav wrote:
Need to replace the main board with a dinosaur fans 50 plus pins. All three of my rv s needed this upgrade.

Replacing the main board won't do a thing if its the flame proofer causing the problem.

[Pauljdav]

Need to replace the main board with a dinosaur fans 50 plus pins. All three of my rv s needed this upgrade.

[rrupert]

I just had a similar problem, the flame would ignite sporadically or I got the timeout with the ignition problem code. I could hear the ignitor sparking, the voltage was good, but I found the gas regulator was going bad and was not allowing enough pressure. I switched the regulator and all started working fine. I believe the oil that comes from the LP tanks deteriorates the diaphragm over time.

[Old-Biscuit]

SidecarFlip wrote:
Mr. Biscuit will be along and diagnose your issue and tell you the proper procedure to fix it.

'wkamper' done hit it on the head.

Circuit board not seeing the flame lit miliamp signal so it drops the DC to gas valve. 3X then 'locks out'

[wkamper]

Check the connection at the ignitor. It can be good enough to create a spark but, will not be good enough to send the return signal that there is a flame. I experienced this on our furnace at one time and also later on our water heater. Cleaned the connections and working fine since.

[SidecarFlip]

Mr. Biscuit will be along and diagnose your issue and tell you the proper procedure to fix it.

[newman_fulltime]

bad propane regulator

[Sea_Dog]

Long shot.
I had this problem,
the service guy found a small knat (bug)
in the orifice.
He said this is very common!

[corvettekent]

It could be low battery voltage.