Suburban SF30 Furnace

Rob,

You have an interesting problem.
I just went through my documentation and it looks like there is no easy way to determine whether the failure is the electrode or the control board. The fact that it will restart the same cycle after a short power down would make believe that it is the electrode as it serves as the flame sensor and it sounds as thought that is not happening on the re-lights.

The gasket for the door to access the electrode looks to be flat and you should be able to find appropriate gasket material locally. Electrodes are nothing special, just a piece of stainless steel in a ceramic holder. I have even purchase universal cut to fit. But before you do anything else, check the electrical connections to it. I recall once have a bad connection and the burner would light and then shut down on "no flame" some time later when the connection cooled off.

I wish you the best of luck an hope that the blasted thing fails solidly so it can be effectively diagnosed. I hate intermittents.

Matt

Every time I needed to repair a suburban furnace it was the main board. I have always replaced the original with a Dinosaur 50+ pins board. No problems so far with the new board and super easy to replace.

Maybe low propane pressure. Have the same furnace and didn't use it all winter then I tried after new tanks and works great. New complete tank not just refill.

Another option - mounted to the blower housing (on my unit) Was the delay relay, a black circular device with numerous wires affixed. The cap on my unit cane loose and intermittently would allow then refuse to allow ignition. It's worth taking a look at. I repaired mine by holding the relay cap in place & applying a teeny bit of superglue (aka.cyanoacrylate)to the area around the cap. This repair actually held for 2+ years. PS: the key word there is TEENY - too much adhesive and the whole thing becomes one huge bonded together mess.

Thanks for all the advice, fairly sure it's not the relay as I checked for a voltage whilst lit and when it shutdown but worth checking it closer. I think I will be best to replace board and electrode. Any suggestions as best place to get parts? Anyone know of a UK supplier?

Thanks