Heating, Air Conditioning, Fridge, HVAC/furnace


QUESTION: I have an older gas furnace in my home. I tried lighting it for the first time this year. The problem is when i light the pilot and turn the unit to the on position and turn the thermostat on the pilot goes out every time. I tried another thermocouple that wasn't new and its doing the same thing. What can be the problem?

ANSWER: Hello Hosie, To narrow this down a little bit, try lighting the pilot but don't turn on the stat. I want to see if the pilot will stay lit for say 10 min. Is this a standing pilot or is there a spark ignitor? Post the brand and model number and we can go from there.

---------- FOLLOW-UP ----------

QUESTION: The furnace is a JOHNSON   Model# Has80AR      G27 for natural gas.
The pilot light is a standing

Hey Hosie, I don't come up with anything on that model#. Is the pilot light engulfing the thermocouple? I suspect that the tubing to the pilot might have a blockage. Remove the tubing and run a small wire though it. Also check where the tube connects to the valve and make sure there's no crud in there.

Let me know what happens.

Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts


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!

©2016 About.com. All rights reserved.