Hello everyone,
I am writing you all because I am having a problem with my furnace. The fan turns on when the temp stat is set to auto. When set to heat nothing happens.The steel gate in front of the burner opens, but nothing else happens. I thought that the igniter wasn't working and that the Johnson control unit had gone bad. I replaced it with the Honeywell upgrade but the same thing is happening. I don't smell any gas in the burner. The fan works and the burner gate opens, the mother board must be functioning at least partially. Could this be a problem with the pilot needing to be adjusted. Or could this be electrical, spark not operating because of a faulty signal from the mother board to the control unit. Any information would help me out greatly. Thank you all for your time.

Cheers,
Mary Isis

Mary before you spend any more $$ I suggest you call a local Professional for On Site repair. There are way to many items that can cause problems on a Lennox and so far all you have accomplished is spending money for nothing. Bite the bullet and call a local HVAC company. The work that needs to be done on your unit since you have made modifications to components needs to be done ON Site so the system can be checked while activated and the defective part(s) found and replaced.

Hi,
Thank you for the quick reply. I would have an hvac repairman over but money is really tight right now. I would prefer to at least take a shot at trying to fix the furnace. I'm going to send back the Honeywell control unit. I do understand this can be complicated but the system seems intuitive. Is there any troubleshooting recommendations. Like I said, I don't smell gas at the burner. Could this have anything to do with the pilot needing to be adjusted? Any advice would be greatly appreciated.

Cheers,
Mary Isis

I understand your situation but I gave you the best advice I have for your circumstances. The problem could be anywhere in the unit or system. I suggest you but a very good electric meter and learn how to use it. Most of these problems are electrical in nature and replacing all the parts will get expensive over time. Good luck.

Hi,
Thank you again for the reply. It does seem that it could be electrical. As far as electrical parts are concerned it seems that the main electrical components are the control unit and the mother board. Are there any other electrical components that I should be aware of?

The furnace is full of electrical components. Switches,relays,ignitors,transformer,limit controls,fan controls.