I have a 2001 RUUD Silhouette II furnace My thermostat is set for 74 degrees upstairs but the actual temp is only 64. The furnace kicks on then the flames go on for about 5 seconds then go out. It it will repeat this a few times then the furnace will just stay off for a while. Once in a while the flames stay on and the furnace starts heating the house. Does anyone have any suggestions?

I have a 2001 RUUD Silhouette II furnace My thermostat is set for 74 degrees upstairs but the actual temp is only 64. The furnace kicks on then the flames go on for about 5 seconds then go out. It it will repeat this a few times then the furnace will just stay off for a while. Once in a while the flames stay on and the furnace starts heating the house. Does anyone have any suggestions?


Clean the flame sensor if so equipped by sanding clean the metal rod.

I agree with the cleaning of the flame sensor. But be careful using sandpaper the glue from the paper can coat the sensor causing more damage than good.

I used to recommend steel wool and I used to carry copper wool (spun copper) to clean all my electrode jobs including oil burner electrodes. The copper was cleaner,left no residue, and did not rust. The problem was finding the stuff. Also did a great job on copper fittings when used with a glove on the holder hand.

I've never had any problems w/ plumber's cloth.

I agree mark, I have never had a problem with, steel wool, sand cloth, sand paper, or any abrasive cloth. I have heard people recommend cleaning the flame sensor with a dollar bill. This is not going to do the job. You need to clean the flame sensor until it shines like new.

I also agree with hvac, if you use sand paper, make sure it is new. You will be able to see if there is any glue on the senser. If there is , just clean it with a new piece of sandpaper.


Most important thing is... make sure the flame senser is completely clean.

If you clean it good enough, you should be able to blow any residue off by mouth.