Used Rheem 50gal water heater - Pilot won't light...Any ideas?

xmjm924x

I have a used 50 gallon Rheem "Fury" series water heater (built in 2005) that I just installed, but we can't seem to light the pilot flame. We hooked up the gas line and turned on the gas. Then we turned the dial to "pilot", held down the pilot-gas button, and depressed the "Piezo igntion striker" button several times (that's what the directions said to do). We observed through the little glass window either a lone spark or spark accompanied by a brief flash (like what you would expect to see when you were lighting a small gas source). However, we never once got a sustained pilot flame even though we were still holding down the pilot-gas-source button.

Does anybody have any ideas of what might be wrong?

Here's the specific info on my water heater...

Rheem Fury Series
Manufactured 2005
Model # 42v50-40F
50 Gallon

Thanks for any help.

Grampa Bud

That used to be Rheems standard direct vent 50 gallon model before power vents came along. Even new that piezo-electric ignitor was shaky (Probably made in China). Don't rely on it or you may have an even brighter flash some time.
Depending on how long you had the gas line open while you were repiping the heater you could have a large bubble of air trapped in the main gas line somewhere. If you saw a small flash when you tried it the first time (lighting the pilot) some of that bubble is getting bled off. Get yourself a butane fired "stick" lighter; about $1, with a 6-7 inch long tip on it and continue to try lighting it just as the directions say, but without using the piezo lighter. If the pilot won't remain lit after after you have flame for a minute or so replace the thermocouple. Make sure you look at the face of the gas valve also because some of them had a "pilot light" position and anywhere else on the dial let to much pressure through to light and sustain the pilot. DO NOT TAKE THE GAS VALVE OFF OR APART.

AllanJ

Holding down the pilot-gas button but not pressing the piezo button will also bleed off the air pocket although how long to hold it down is guesswork.

To be safe, do this:

Use bellows to blow out the underside of the water heater. Hold down the pilot-gas button, wait three seconds, press the piezo button once, and see if the pilot light came on. If not, keep holding the pilot-gas button for two to three minutes. Let go and go away for five minutes to let gas dissipate just in case the air pocket was small and lots of gas came out. Repeat.

If the pilot won't light while you have the pilot-gas button held down, the thermocouple is probably not the cause.

After the pilot light comes on, hold the pilot button for another 60 seconds. Then, if the pilot light goes off when you let go, the thermocouple is suspect.

__________________
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xmjm924x

Thanks for all of your helpful replies people! With some good feedback and a helpful suggestion from a member of a different DIY forum, I was finally able to identify the problem and ultimately succeed in getting the pilot lit. After purging the gas line a few times with no success, I decided to completely disconnect the gas-supply line from both ends and blow it out repeatedly with about 120 psi from a compressor. It was that last attempt at finding a solution that without-a-doubt took care of the problem. The pilot is now lit and I am finally able to enjoy a hot shower for the first time in two hellish weeks (lol). Thanks again for all your help guys!...You really helped make a difference in my situation!

-Mike

how

I'm glad you've fixed it but your method makes little sense to me . Just what do you think you cleared from your main gas line that would of helped?

frnkhtc47

using compressed air probably blew out rust from inside of the gas line.

Grampa Bud

If it was really rust- That had to be one Hell of a pile of it to stop that little whiff.

veesubotee

Considering my (non-pro) experience with water heaters over the years, when lighting the pilot, the thermocouple doesn't affect the flow of gas to the pilot flame: hence the need to 'hold down' the button to allow gas to flow through it, and turn the valve switch to 'pilot'.

Once the pilot is established, releasing the button and turning the switch to 'on' (or whatever), will allow the thermocouple to 'control' the gas valve.

V

Grampa Bud

Actually the thermocouple DOES affect the flow of gas to the pilot flame. The thermocouple replaces your thumb or finger pushing down on the button for the gas valve. By pushing down on the gas valve button you are opening a small poppet valve within the main gas valve body that will allow a predetermined amount of gas (small but adjustable) through to the pilot assembly. Once the pilot has been lit the thermocouple heats up rapidly (about 45 seconds) and the contents of the thermocouple capillary tube puts enough pressure on the button end of the tube inside the main gas valve to keep the pilot poppet valve open just enough to maintain the pilot flame. After the pilot flame has been established the thermostat for the water heater (also adjustable) takes over and by your setting - LOW - MEDIUM - HIGH - will open the main gas valve poppet for the main burner for as long as needed. If the gas pressure to the heater drops for some reason or the thermocouple goes bad, the pilot will extinguish and both poppets in the main valve body will close. The main gas WILL NOT WORK without the pilot and thermocouple functioning properly.

sublimesed

I know I shouldn't piggy back the OP's thread, but I have a similar issue however my Rheem Fury 42v50-40F (manufactured in 2004) was working yesterday and stopped last night. It has been working the past 2 years I have lived here.

I have gotten the pilot light to relight twice but when I move it to the ON setting it just goes out.

Any tips would be appreciated. Thanks in advance.

EDIT: after reading these posts more thoroughly I am going to assume that would suggest it is the thermocouple. Please let me know if my assumption is wrong

how

If you can get the pilot to light and stay on in the pilot position with your fingers off the valve, and it goes off immediately when you turn the gas valve control to "on", then the gas valve itself is suspect.

sublimesed

Do you have a site, other than eHow, you recommend to follow for replacing this?

I really dislike that site generally take that site's advice with a grain of salt.

how

Hey Sublimesed
Is there a freebee site of advise that you shouldn't take with a grain of salt?
Changing your own gas valve has some variables to it that make me nervous recomending it as a do it yourself project.

You should also post a couple of pic's first of the gas valve from a couple of angles just to make sure there isn't any odd pilot controls that I've missed. There are a hundred plus different gas valves out there.

sublimesed

Well said...

Thanks! I will do that as soon as possible.

sublimesed

I have them attached for you..let me know if you need anymore pictures. It is hard to take pictures because there is a table with a lot of stuff on it in the way, but if need be I can move it.

Nevermind the lent..it is in a laundry room

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