1972 Safari heater problem

[silverkeeper]

We have a problem with a 1972 safari furnace. After the furnace is started and is running for awhile the pilot shuts down causing the burner to stop and then continues to blow cool air into the space.
Anyone know about this and how to fix it.

Thanks

[cameront120]

If it is equipped with the Suburban NT22a, there was a recall for that furnace back in the day. If it was never repaired, you may want to consider replacing it with a new model. If you're certain that it had the recall repair done, then you could explore repairing the problem you're having (I'm sorry I don't know the solution to your actual problem).

[TG Twinkie]

Have you checked the exhaust port? It could be blocked.
If so, the high temp limit could be shutting the burner off. The sail switch may be a problem as well. You could also have a bad thermocouple.
When you light the pilot. How does the flame look?
I would start by cleaning any residue from the thermocouple. If that doesn't work. Try replacing the thermocouple. Then make sure it is in the flame if the pilot.

[idroba]

What TG T said plus the cast iron burner may be filled with rust causing a poor flame which then starves the pilot.

Suburban no longer supports any parts for those pilot light models either.

The furnace is 41 years old now. It may be time to consider just replacing it for safety reasons. Combustion chambers rust out, the recall mentioned above may not have been done, and pilot light furnaces are a PITA vs. the new electronic ignition ones.

[silverkeeper]

Thanks so much for the info, I will check this out.

Best

[Inland RV Center, In]

Originally Posted by silverkeeper

We have a problem with a 1972 safari furnace. After the furnace is started and is running for awhile the pilot shuts down causing the burner to stop and then continues to blow cool air into the space.
Anyone know about this and how to fix it.

Thanks

Could be a weak pilot light or a weak thermocouple.

Andy