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Lennox g26-75 fan not turning on in automatic mode

Recently replaced the Johnson ignition control module with Lennox 30W33 OEM Ignition Control Kit with a new flame sensor. It cured the cycling problems, but now the fan doesn't go on in automatic mode after the furnace fires up. After a few minutes the burners go out. When I put the fan in manual mode, everything works fine. What's up!!

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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

  • 85 Answers

SOURCE: Heater no longer works on auto fan, only manual fan

When you call for fan in auto ensure your getting 24 volts at pin on control board, if it is not energizing then there is a problem with the relay.. Before you change out the expensive control board, try the therm..

Posted on Dec 09, 2008

  • 91 Answers

SOURCE: lennox lf24 garage heater, starts then shuts down.

Here is a link to the manual for your unit heater:

The 4 flashes is a high limit or roll out switch is open. There are 2 or 3 little brown or black button looking switches with a little button on the top and a wire attached to each side. Press the button on each, you may hear a slight "click". If you do, that is the one that was open. Hope this helps.

Posted on Nov 04, 2009

  • 215 Answers

SOURCE: lennox intermitent flame problem

Yes the flame sensor is not allowing the ignitor to start, you will need to remove the flame sensor, and clean the black carbon build up from the stem of the flame sensor, replace the flame sensor and turn the furnance back on, this will correct the problem.

Posted on Dec 14, 2009

  • 1 Answer

SOURCE: lennox furnace 17 yeanrs old. flame comes on and

I have a Lennox G40UH furnace. The burners fail to ignite about every 5th time. The furnace will try to ignite the burners then shut down. Once in a while the temp will drop down to 62 then fire up. I have only gotten a Diagnostic code once "Watchguard - burners fail to ignite" once I shut the power down and it started.
The furnace is clean, 5 years old, the flue is not clogged.

Posted on Jan 03, 2010

SOURCE: I have Lennox pulse 21 control module light goes out

If this is a high eff model, check to make sure the intake vent is not plugged.

Posted on Jan 18, 2010

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Troubleshoot an ignition problem on a Lennox gas furnace ...

? 2:44
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This furnace should light its pilot with a spark then the pilot proves its on ... Troubleshoot an ignition problem on a Lennox gasfurnace .... Pilot and no inducer but is the same model as that great video! ... You probably have dirty burners. ... How do you know spark module is not sending 24 volts to mv and pv ...

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