Heating, Air Conditioning, Fridge, HVAC/Follow up question


HiJim, I wanted to make sure I understand clearly what you have told me. I understand that the fan should be wired to the 120v side of the transformer. You have said to connect the red wire from the transformer to the red wire going to the sensor. The other wire from the sensor connect to the gas valve. The other wire from the gas valve you said to connect it to the Green wire from the transformer.

I wanted to make sure you understood that the green wire on the transformer is not a common or return wire. It measures the same voltage as the red wire.

It makes sense to me that I don't need the relay switch since I am not using a thermostat.

So, basically I am just wanting to clarify what to do with that second wire from the gas valve.

Thanks for your help.

Hi Don, yes the green wire is a little confusing. Normally green is use only for grounding. Can you send me a pic of the transformer?

How did you measure the volts on the transformer, between green and red? How many wires are on the low voltage side of the transformer?

Heating, Air Conditioning, Fridge, HVAC

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Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

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