Architecture
E State Road 26, Russiaville, IN 46979 Farm House Built in 1860
E State Road 26, Russiaville, IN 46979 House Built in 1860 25 acres Note the walls have wood panels part way up.
Air Conditioning
Old Gas Furnace DeBugging
Symptoms
The gas main burner would turn on and the fan limit switch torsion switch would rapidly rotate turning on the air handler fan motor then it would appear that the heat exchanger would cool down as you would observe the fan limit switch rotate quickly towards the cool side. This would end up turning off the motor. The air handler fan motor would cycle on and off in short cycles.
Fix
I bought a new fan limit switch and replaced the existing unit. Now the furnace acts as I would have expected it to. My unit uses the 8 inch long Honeywell part number: L4064B 2236 L4064
Notes
- Fan limit switch unit price is very gougy from retail sources like furnace fixit shops. Bush Heating wanted 150 US dollars. I ordered one from ebay for 64 dollars.
The fan limit swich bimetallic torsion bar must have failed in my
Fan Limit Switch
- Fan does not turn on until heat exchanger has reached set termperature
- If the motor stops working the gas is turned off if the heat exchanger reaches the limit temperature
Control Circuit Diagram:
Sunbeam Seneca SL-XXX
Research Links
- Test and Replace the Fan Limit Switch on a Furnace
- Gas and Oil Controls:Automatic Pilot Safety Valve – Explains how the mechanics of the pilot light and main gas valve
How the Pilot Light Safety System Works
Architecture
Old Pine Wood in the Top of the Interior Door Framing from 120 years ago
Pine from 120 year ago appears to be much more beautiful than the stuff we are getting from tree farms. See photo below for an example:
That is pine.