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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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We have a Laars lite LLG 125 natural spa boiler. It was shut

Customer Question

We have a Laars lite LLG 125 natural spa boiler. It was shut down for the last month or so. Trying to fire it up for the season, pilot lites but no main burner. After checking all the safety curcuit parts , I finally took black wire from the block that has the pot an sensor wires. Hooked it to the gas valve an it fired right up. So how do I test the sensor or the thermostat sender.
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Welcome! We keep going until you have all of the information you need.[b/]. Extensive training & coaching also available.
If you can send be a clear, well lit and well focused photo of the wiring diagram glued to the inside of service panel, with a red dot on the parts you are referring to, I can coach a person to a diagnosis in most cases.
Use the 'attach files' link at the lower left of your reply box to do that please.
Customer: replied 2 years ago.
Sorry I'm not able to get a picture, if I knew how to test the sensor that works with the thermostat dial then I would no whether to replace just the sensor or the complete on off thermostat control
Expert:  Phil replied 2 years ago.
Hello again
Look pages 7 and 8 over please and tell me which of the diagrams matches your unit.
We can go from there.