Furnace Won't Light

[trooper253]

I have a Suburban SF-35F furnace in my 2008 Cedar Creek 362 BSA that is giving me trouble. When I turn it on the blower comes on and I can hear the igniter trying to light. I also can smell gas at the outside vent, however it will not light. It appears to be getting adequate air flow so I am at a loss. Any sugestions will be greatly appreciated.

[Timex]

Has it had problems lighting before? Is this on initial startup? Upon the first startup, I have to light an eye on the stove to get the gas flowing.

[Herk7769]

If the flue is blocked by a spider nest or mud dauber nest, the mixture will be wrong and it won't light. As I said in a previous thread, there is a "3 strikes and you're out" circuit that will prevent any more attempts until it is shut off and turned back on again.

Also if you smell gas; everything is working except the "fire."
The only thing that will prevent the fire is mixture and spark.
If you hear spark that only leaves mixture (too rich - not enough air or too lean - not enough fuel for the air)

[trooper253]

I went out to check the airflow again and covered the intake to see how much air it was getting. When I did this the furnace lit but it would go off and start trying to light again when I moved my hand. I held it there long enough for some way to build and then it stayed lit. I let it run for about 15 minuets an then cut it off and let it cool off. I turned it back on and it worked as expected.

This unit had been in storage for a while before I bought it and this is just one more bug I have had to get worked out.

[Herk7769]

LOL sounds like you burned that spider web right out of there!