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 HVAC Guru Your Own Question
HVAC Guru
HVAC Guru, HVAC TECH
Category: HVAC
Satisfied Customers: 14032
Experience:  15yrs in the HVAC industry with certificates and degrees.
21107370
Type Your HVAC Question Here...
HVAC Guru is online now
A new question is answered every 9 seconds

Rheem 90 percent furnace. gas valve won't stay on. can;t

Customer Question

Customer: ***** *****. Rheem 90 percent furnace. gas valve won't stay on. can;t locate flame sensor. So I wonder if the hot surface ignition is flame sensor. Hot surface glows and lights burner but on inspection it looks like it is cracked. I checked continuity and is good.
JA: Thanks. Can you give me any more details about your issue?
Customer: I changed circuit board, changed gas valve, changed pressure switch, checked all 24v limits, high limit, have power to all. Gas valve go's out after 5 seconds
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $18) to post your type of question to HVAC Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: I could but I left model number, serial number at parts house so I don't have that information on me
JA: OK. Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 11 months ago.
Category: HVAC
Expert:  HVAC Guru replied 11 months ago.

Hello and thanks for using this service, if you have been waiting do not worry or get upset I am just one of the techs on here and I try to get to as many customers as I can and I just picked up your question now. Please give me time to respond sometimes I get your replies late so there may be a delay in my response.

The flame sensor is a metal rod have you tried to clean it with sand paper?

Customer: replied 11 months ago.
rheem 90% model rged 10erajs does not have a flame sensor that can be cleaned with sandpaper. Does the hot surface coil act as a flame sensor. If it were that easy I would have done so. Give me something I can use, good information, thats why I called you. This one is not so easy as metal rod flame sensor
Expert:  BillyHvac replied 11 months ago.

Hello,

My name is ***** ***** I am a different tech. You are correct in that this unit senses through the ignitor. It is possible to have ignition yet not have proper flame rectification for flame sense.

The most common issue is to change the ignitor, next would be the ground to the board and to the furnace.

The final item would be board. I would start by checking grounds and make sure they are clean and tight...then move to ignitor if necessary

Billy

Expert:  HVAC Guru replied 11 months ago.

If the ignitor is really white looking in color it is likely bad and the cause of the issue. Check it out and get back to me thanks

Expert:  BillyHvac replied 11 months ago.

Hello,

I am Billy, the one who knew you did NOT have a flame sensor.

It appears the previous tech who did not know this and recommended sanding a sensor that was not there, is now wanting to change sensor answer to a white ignitor..

Please check the grounds and ignitor as Billy mentioned and disregard responses from the incorrect tech.

Thank you,

Billy

Expert:  HVAC Guru replied 11 months ago.

Yes just get back to me if you need any further assistance thanks

Expert:  BillyHvac replied 11 months ago.

Hello,

I am Billy, the one who knew you did NOT have a flame sensor.

It appears the previous tech who did not know this and recommended sanding a sensor that was not there, is now wanting to change sensor answer to a white ignitor..

Please check the grounds and ignitor as Billy mentioned and disregard responses from the incorrect tech.

Thank you,

Billy

Expert:  HVAC Guru replied 11 months ago.

Yes just get back to me if you need any further assistance thanks

Expert:  BillyHvac replied 11 months ago.

Hello,

I am Billy, the one who knew you did NOT have a flame sensor.

It appears the previous tech who did not know this and recommended sanding a sensor that was not there, is now wanting to change sensor answer to a white ignitor..

Please check the grounds and ignitor as Billy mentioned and disregard responses from the incorrect tech.

Thank you,

Billy

Expert:  HVAC Guru replied 11 months ago.

Just get back to me if you need anything the childish behavior of the other expert is uncalled for talk to you soon. The site frowns on this behavior in front of the customers and I think that will be corrected so I apologize in advance for this.

Related HVAC Questions