repairing a Suburban furnace

23hotrodr wrote:
The new ignition control board fixed it immediately. It works great now!

Thanks for the assistance.-- Mick

I am not surprised that is the fix. I hope you used a dinosaur brand. The original boards are not soldered very well and the solder joints fail with the vibration. The dino boards are built with much better quality.

My furnace lasted two years before the board failed. My brothers lasted 3 years and I also had to replace the board on my class C I had before I bought the new TT.

The new ignition control board fixed it immediately. It works great now!

Thanks for the assistance.-- Mick

Thanks to both of you for the information.

The furnace was not lighting. I could hear it attempt to light, but never could hear any spark. I did smell gas and could hear the solenoid and relays clicking. After 3 attempts, it would lock out.

I removed the ignition board and its mounting bracket to try and see if I could get to the burner assembly and ignitor for an attempt for a quick clean and look for obvious issues. I could never get near the burner.

I worked the connector on and off the edge of the board a couple times in attempt for better connection. Now with all re-installed, it does not even open the gas valve.

One thing that I find annoying with this furnace is that it runs the blower for what seems like a long time before attempting to light. And then when the thermostat is turned off, the blower continues to run for a long time before it finally turns off. It does this even if the burner has never lit.

I have a new Dinosaur Electronics UIB-S ignition control board on order. After it gets here, I'll pull the guts out of the furnace and try and fix it.

I willalso try and download the mentioned manual.

Thanks again for all the good info.-- Mick

I just watched a technician remove my Suburban furnace. Mine came out through the grate under the fridge. He removed the front cover, disconnected the gas line, disconnected the wires and removed a couple of screws and slid the whole thing out through the hole where the grate went. He could access the burner and the orifice and everything when he had it on his bench. He was able to test it using my BBQ hose to the quick disconnect. The tough part is getting the unit back in. It would help to have someone outside to help you line up the fresh air intake and the exhaust when reinstalling it as they have to fit into pipes and there are two so it can be a little tricky.
Mine had a birds nest built on top and around the orifice. Couldn't see it until we removed the furnace

23hotrodr wrote:

It appears that there is one screw at the base of the blower housing that can be removed and will allow the entire guts of the furnace to be pulled out. The 4 wire connector underneat the cabinets must be disconnected and the gas line disconnected at the furnace.

That's it, though there could be a screw on the inside as well- if they didn't remove it when it was installed.
I have the manual on my service manual page.

What is it doing? The most common problem I have with that model is a corroded limit switch- while the boards do go bad, they are far more reliable than they used to be.