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How does the blower engage on a johnson gas forge 120-k


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I recently purchased an old Johnson gas forge.  It is a 90,000 btu shaped like a mailbox model number 120k.  I am not familiar with its operation.

The question I have,  is what controls the blower motor.   I light the pilot light, and hold the button,  but it will not stay on,  it goes out when I let the button go.  When I flick the blower switch,  nothing happens.  I suspect that the motor will not blow until another gas valve switch allows it to.   I think the thermocouple may not be working.  Is this a unit universal?  Is it something I can get from Lowes?   Thanks in advance.   Corey

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Welcome aboard Core, glad to have you. Please put your general location in the header you'll be surprised at how many IFI folk live within visiting distance.  You can contact Johnson Gas Appliance for help. I sure don't know.


Frosty The Lucky.

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I did find a thermocoupler at Lowes.   8.00    and it fit.   But that was not the problem.    Nothing came on when I turned the switch on.  So I jumped the switch, and the motor hummed and the solenoids clicked, but motor did not turn.   I opened the vent of the vane chamber and realized the motor was not free.  The motor has a grease tube.  I put some wd40 in it, and I also lubed it from the front shaft.   It began to loosen up slowly.  Once it appeared loose enough,   I applied power to it.  The blower came on, and after a minute it came up to full speed.   I lit the pilot, and the chamber fired up.  It coughed and  backfired when I would close the door.  It was a little scary, as I was worried it would backfire and burn me.  It even popped and made the door open.  So I closed the door partially.  and it didn't backfire as much.  After about five minutes,   The internal chamber heated up cherry red, and it quit backfiring.   Then I closed the door completely, and it didn't cough or backfire at all.  After running about 15 minutes, and it was smooth operating.    I suspect the unit may not have been run in 15 or 20 years,  so maybe that was part of the backfiring problem.    The only problem I have to fix,  is the switch.  It looks like a 1960's switch,  so I don't think I'll find one like it.    I paid 11.00 for it at the school board auction.   I think I made a good deal.

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