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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I was just googling how to fix my HVAC. I too have my

Customer Question

JA: Hi. How can we be of help?
Customer: I was just googling how to fix my HVAC. I too have my diagnostic light flash 4 times telling me to open the high temp switch. Just trying to figure out where I can find them.
JA: Are you an HVAC professional?
Customer: Nope DIY
JA: Do you plan on doing the work yourself?
Customer: I do
JA: Anything else we should know to help you best?
Customer: That's all I have for now. I'm technically inclined.
Submitted: 8 months ago.
Category: HVAC
Expert:  Handyman Matt replied 8 months ago.

Can you tell me what symptoms you are experiencing as well as the make and model of your HVAC unit?

Customer: replied 8 months ago.
Lennox 80UHG3-75A-3When I turn on the heat it just blows air. No heat. I looked at the diagnostics LED indicator and it flashes 4 times. According to the flash codes that means I need to open the high temp limit switch.And now I'm trying to find them.Would you like some pictures of my unit?
Expert:  Handyman Matt replied 8 months ago.

The switches should be located on top of the burner box. One switch on each side, just above each burner. I have attached a manual that may help (or you may already have). Each switch should have a button in the middle that may be popped up. Pushing it in will generally reset the switch. Page 6 shows the switch locations and pages 12 and 13 explain resetting the switches. Let me know if you have any questions. Thanks!

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