How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Phil Your Own Question
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

My 40 year old Gaffers & Satler (S120), burners turn off

Customer Question

My 40 year old Gaffers & Satler (S120), burners turn off befor the set temp. is reached.
It seems to cycle on/off every 4 to 5 minutes.
Also I can't locate the fan limit switch shown on the furnace sticker.
Any suggestions?
THanks, RCV
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

May be tough for me to find a manual on one this old.Can you send a picture of wiring diagram and unit?

If you have a paper clip icon on your page you can attach using that link.Or

You can upload the pictures using the tiny pic site .

Here is a link to the site.

Click on Browse , select the file from your folder.then click UPLOAD NOW.

They will give you a quote to enter in the box to verify you are a human.Enter the quote and click UPLOAD NOW

You will see your picture on right side of screen.

Then copy the link URL for email & IM

Paste that link here on the site.

Expert:  airheatman replied 1 year ago.

Possibly like this

Customer: replied 1 year ago.
My immediate concern is the burner cycling on & off, (there is no electrical diagrahm).RCV
Expert:  airheatman replied 1 year ago.

Do you see a limit with with a set point of between 200 and 250 with 2 wires going to it in the circuit to gas valve?

Customer: replied 1 year ago.
OK, I see there is no easy answere here. Please end session, & thank you...RCV