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 Accurate Joe Your Own Question
Accurate Joe
Accurate Joe, Owner of Accurate Mechanical.
Category: HVAC
Satisfied Customers: 165
Experience:  25 years experince in HVACR field. I am a master electrican. I own an operate Accurate Mechanical,
12533851
Type Your HVAC Question Here...
Accurate Joe is online now
A new question is answered every 9 seconds

Pilot light on my water heater is lit, but burner does not fire

Customer Question

This is a propane powered water heater, 40-gal. The problem started
a couple month's ago. We'd discovered the pilot light was out, but the unit would fire up right away upon re-lighting. This has happened maybe four times in this time period. Today the pilot light was lit but the burner wouldn't fire. We have ruled out the gas line to the house as the boiler and other gas appliances are working fine.

Submitted: 7 years ago.
Category: HVAC
Expert:  Accurate Joe replied 7 years ago.

Good day and Welcome to Just Answer

It sounds like you have a bad thermocouple.
You need to be competent to work on this type of appliance. Gas is very dangerous. Never work above your skill level.
On your gas valve you have a small copper line that runs to the pilot flame.
Make sure it is at least 40% in flame.
If you have a meter to read millivolts, when under flame it needs to register above 15 millivolts. Here is a link for the thermocouple. Click on blue word. Get the length you need for your application. You can buy them at Lowes.
The thermocouple should cost under 20 dollars.

Accurate Joe, Owner of Accurate Mechanical.
Category: HVAC
Satisfied Customers: 165
Experience: 25 years experince in HVACR field. I am a master electrican. I own an operate Accurate Mechanical,
Accurate Joe and 4 other HVAC Specialists are ready to help you
Customer: replied 7 years ago.

Hi,
It appears the problem with the water heater is a little more complicated than I first anticipated. We replaced the thermocoupler as you suggested. Not known to me when I first communicated the problem last evening, the problem is more complicated.
I have checked out the situation myself instead of relying on my significant other for an accurate description. My significant other replaced the thermocoupler but now the flame is going everywhere but to the burner. It seems to be coming out a 1/4" diam aluminium line running from the ignition unit toward the burner. This line appears to be crimped or bent and possibly cracked about 1 1/2 " from the end closest to the burner. There is no flame on the burner at all. Is this fixable with additional parts?

Expert:  Accurate Joe replied 7 years ago.

Cut the gas off. Is it possible that in changing the thermocouple, the pilot tube got, took half way off and crimped. That is the pipe to your pilot. You will have to loosen thermocouple and main gas to burner, and pilot tube to slide the whole burner out. At that point you are going to need a new pilot line. You can get at HVAC supply house. Put it back together. I will post in next post a You tube video on changing the thermocouple.

Accurate Joe, Owner of Accurate Mechanical.
Category: HVAC
Satisfied Customers: 165
Experience: 25 years experince in HVACR field. I am a master electrican. I own an operate Accurate Mechanical,
Accurate Joe and 4 other HVAC Specialists are ready to help you
Customer: replied 7 years ago.

Ok, the saga continues. We have a new thermocouple, pilot line and cleaned burner. We have a good strong pilot flame. Now for more information. Our water heater is vented with an electric fan that is wired to the main valve by four wires. Two of the wires are clipped onto a front "solenoid" and two wires are hooked to what looks like a small "fuse" unit on the side of the main valve. Earlier this afternoon, we thought the problem was fixed. After the burner assembly was re-installed and the water heater re-lit, the fan came on and the burner ignited and we had our first tank full of hot water. The burner shut down and will not re-fire. We started looking at the connections to the fan. It appears that when we pull off the two wires to the "fuse-looking" module on the side of the main valve and re-connect them, the fan comes on for a few seconds and the burner fires, then the whole thing shuts down and we're back to a nice looking pilot light.
That was happening hit or miss. Now when we repeat that process, nothing happens.
Any suggestions? If I haven't described this well enough, maybe I could take a photo.

Expert:  Accurate Joe replied 7 years ago.

Your image need to be Jpeg file and just hit the tree and download, or you can post to photo bucket and copy the address from title bar and post.

Give me the Make and model of water heater and the fan device.

Customer: replied 7 years ago.

It is a AO Smith "Powershot" Power vent water heater. The fan assembly
is Fasco Industries brand. I can't find a model number.

Expert:  Accurate Joe replied 7 years ago.
Good enough
Customer: replied 7 years ago.

As far as I can tell the water heater is a 50 gal (not 40 gal as earlier stated) and
the model no. is FPS 50 217. There is also another number that may help. That
number is FPS - 50 - J01P040S19. There is also a serial no. MD92-0052902-S19.
Let me know if this doesn't help and I'll look for more numbers.

Expert:  Accurate Joe replied 7 years ago.

Double check your numbers, they are not matching.

Customer: replied 7 years ago.

It is the night before Thanksgiving. We got someone over to fix the problem but under other circumstances, I would have waited for you to help us. I know the problem would have been much worse and prolonged had it not been for your expert attention. Thank you again.

Expert:  Accurate Joe replied 7 years ago.

Thank you for your time and look forward to hearing from you again.
Happy Thanksgiving and God Bless.

Accurate Joe, Owner of Accurate Mechanical.
Category: HVAC
Satisfied Customers: 165
Experience: 25 years experince in HVACR field. I am a master electrican. I own an operate Accurate Mechanical,
Accurate Joe and 4 other HVAC Specialists are ready to help you
Customer: replied 7 years ago.

Thank you. Happy Thanksgiving and all of us have so much to be thankful for. Have a wonderful day!

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
< Previous | Next >
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Phil

    Phil

    Mechanical Engineer

    Satisfied Customers:

    5389
    Retired HVAC/ Electrical & Boiler contractor. Industrial
< Last | Next >
  • http://ww2.justanswer.com/uploads/AL/alumalite/2012-5-10_234018_shutterstock506249951forJA500.64x64.jpg Phil's Avatar

    Phil

    Mechanical Engineer

    Satisfied Customers:

    5389
    Retired HVAC/ Electrical & Boiler contractor. Industrial
  • http://ww2.justanswer.com/uploads/SE/ServiceTechRus/2012-6-7_2119_056.64x64.JPG gotoman for ac's Avatar

    gotoman for ac

    HVAC Technician

    Satisfied Customers:

    4999
    51 years of experience install design and repair of all makes and models of AC
  • http://ww2.justanswer.com/uploads/skibum0101/2008-12-16_015819_just_answer.jpg Rick Mather's Avatar

    Rick Mather

    HVAC Technician

    Satisfied Customers:

    3133
    35 years experience, HVAC
  • http://ww2.justanswer.com/uploads/RY/Rygis20/2011-5-7_3143_DSC5324.64x64.JPG Matthew's Avatar

    Matthew

    HVAC Technician

    Satisfied Customers:

    2014
    14 years experience in the HVAC field of service, installation, Manual J & D calculations
  • http://ww2.justanswer.com/uploads/KE/kentguidry/2011-9-26_214316_0059.64x64.jpg Kenton Guidry's Avatar

    Kenton Guidry

    HVAC Technician

    Satisfied Customers:

    963
    12 years install/service experience.
  • http://ww2.justanswer.com/uploads/solarman1947/2009-12-13_223915_phpkKBcXq_c2PM.jpg Rick Ridley's Avatar

    Rick Ridley

    UK Heating Engineer

    Satisfied Customers:

    871
    Retired But have had 30 years on the tools, Ex CORGI
  • http://ww2.justanswer.com/uploads/Ironheadfan/2009-12-18_222416_pump_005.jpg Tom's Avatar

    Tom

    HVAC Technician

    Satisfied Customers:

    770
    16+yrs HVAC/R service. Residential Commerical Industrial