Combustion odor L300

[woodauger]

My four year old heater is releasing fumes inside. Run always on power-saver “low”, flame looks perfect. Partial flue obstruction, or heat exchanger? It seems too soon to lose the exchanger. The smell isn’t noticeable at the heater unless I park my nose near the floor at the bottom of the air flow. Thanks for any input. It’s good to see some familiar names. Gary

[hawkins111]

L300's are a pretty good unit and should not give off any smell. If you have had a back fire in the past there could be a problem with the relief gasket on the exchanger. A more probable place to start would be the air hose. The rubber elbow should be all the way on the nipple and the clamp should be tight. Look at the rubber cap on the extra air inlet to be sure it is not cracked. While you are back there, be sure the bent exhaust pipe is all the way engaged on both the stove and the flue pipe. Last but not least, no fuel leak around the sump or fuel line.

[woodauger]

Thanks for replying. I checked exhaust flue after posting yesterday, checked the air hose this morning. no fuel visibIe anywhere. I did notice when running it on high burn that the entire heat exchanger got bright red, and the exhaust flow feels weak outside. We have had a rodent influx here this year. I am wondering if a small one came through the pipe exit and into the exchanger. I plan to disassemble it to check. Thanks again

[hawkins111]

The design of the L300 heat exchanger is much different than the L30. It is unlikely the L300 exchanger is cracked. Because there is a high yellow flame and a red heat exchanger, I think you will have to disassemble your heater and look at the burner ring and burner mat. If either of those items are bad, you can have a high flame. Be sure to look at the relief gasket on top of the exchanger. Parts you will need are, mat w/glue, ring, heat exchanger gasket and flame sensor gasket. Not a tough job if you have the parts on hand.

[woodauger]

That’s the strange part - the flame has no yellow. The smell inside the house is much stronger than what comes out the flue pipe outdoors. The relief plate gasket looks good. , thanks for that advice. I’ll look lower at the burner gaskets

[woodauger]

Okay, the culprit was a gasket hidden inside the burn chamber - the “fuel nozzle gasket”. This rubber device melts with use and the compressive leak protection disappears. A twelve dollar, fifteen minute repair. i’m left with three questions: Why doesn’t Toyo point out the obvious in the user manual? Rubber will never survive this use. Why is there no test mode to keep the combustion fan operating so the heater can be leak-tested cold? And why does Toyo offer a ‘technical contact’ email link that they don’t monitor or respond to? Thanks for keeping me ambitious to keep trying