Upgrading my fan switch, and limit switch

Sep 24, 2019
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United States
I have a 1950's Lennox gas furnace. Its pretty much all original.
I dont think its had many upgrades . I replaced the fan motor last summer.
And AC was added at some point early on.

Its got a magnetic gas valve, a constantly lit pilot light, a mercury switch/flame sensor, fan/limit switches, contactor/transformer, and a newer/older digital thermostat.

The fan switch has stopped working, but the limit switch is working.
I have been running the heat with the fan on "ON"
The unit ( fan switch/limit combo box thing) looks completely different than any I can find on the net. I cant even find an image of one that looks like mine.
It pre-dates the ones that have the dial set up. It looks like 2 completely separate switches, almost like it has two rods that protrude into the duct work.
I have not removed it, so I do not know what the sensors look like.
Its a :
" Lennox Combination Control"
"Type ; 514 NO ; 3 STYLE ; P21"
It also has a paper tag on the inside back of the cover that says " White-Rodgers " , the same brand as the mercury switch.

Can I get one of the newer dial type combo switches? It seems that the temperatures that my switch works at are the same as newer switches.




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