MODINE hanging (pipe) Shop Furnace 55,000 BTU

Flame starts, blower comes on about 30-45 seconds later.
Flame shuts off at about 3 Minutes, blower continues to run about 5 min.
Then cycle repeats.

Side note: Have replaced Thermo Coupler last year and blower this year

( about 15- 20 years old unit, landlord said its my problem not under lease)

Thanks for any thoughts on how to fix myself.

Notaworking today

The heat anticipator in the thermostat could be bad or not adjusted correctly.
Remove thermostat cover. Look for a indicator that says longer then move the lever to longer. If your thermostat does not have one then check the fan and limit controls. See sticky notes at the beginning of this board it has some pictures that may help.

Honeywell biMetal Spring

Have turned the little set screw all the way in for a few cycles annd all the way out for a few cycles to allow more time, but did not work.

Not sure about fan and limit controls ? Have attached picture.

Thanks for any help

Attachment 5686

You might open the box that has the white duplex outlet on it or the transformer plate and see if there are other wires coming out of the furnace and into those boxes. If there are follow those wires into the furnace (note you might have to take off a side cover) to find the controls.

Pulled Cover , found "therm o disk"
Red Black Blue Wires

Thanks

Attachment 5688

That is a 3 wire disc. It may be just a bit more difficult to find but they are out there. Glad to be of help. BTW White Rodgers makes the disc's also.