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: 8768
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 heater is only working very weakly on 1/2 and will go out

This answer was rated:

my heater is only working very weakly on 1/2 and will go out on full.
Welcome to Just Answer!

I will stay with you until the situation resolves. I hold questions open after positive ratings to allow for unlimited follow up.

It is most likely that the draft caused by the flame when it is on full is causing the flame to be pulled away from the flame sensor... and that causes the gas valve to close.

A professional cleaning using compressed air will most likely solve the problem.

These units can be dangerous if not maintained properly by a licensed gas appliance specialist.. in this case a Rinnai gas heater specialist. If you can tell me which direction you are from the center of the nearest larger town or city, I will see what I can do about getting you a list of people to call in your area.... and some advice on how to deal with them.

We can go from there.

Customer: replied 4 years ago.

Is there any procedure I can carry out with an air compressor myself.If not,my nearest major centre is Gosford NSW

Hello again,

You can set the regulator on the air compressor at 30 lbs or so, and carefully blow air into the air intake of the pilot light and main burner air intake, being very careful not to damage any of the parts.

You will have to remove the service panels on the back and on the bottom to do that.

page 6

Let me know how that goes, we can keep going without any time limit as long as you keep rating my efforts as good or excellent.

Customer: replied 4 years ago.

Vast improvement on low setting.Working well.Full setting very weak but does not go out.The compressed air did seem to dislodge some dust.

Good work! I am glad to hear it.

The indications are that a little more work with the compressed air might cure the problem entirely, maybe at slightly higher pressure on the regulator.

On this end the company pays me for my time.... only if you rate my advice good or excellent.


If you can do that i would appreciate it...let me know if you encounter any trouble in the rating process, that will help too.. its been a bit buggy lately.



Phil and other HVAC Specialists are ready to help you