Strange Hot Water Heater Behavior - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 01-09-2010, 03:12 PM   #1
Join Date: Jan 2010
Location: Cincinnati, OH
Posts: 3
Rewards Points: 10

Strange hot water heater behavior

If any resident pro's here could help me out I'd be extremely grateful. I've been having problems with a Rheem Fury Gas (40 or 50 Gal.).

The pilot light keeps going out regularly. After I re-light the pilot light, it seems to be going out either right when the burner tries to turn on or as the burner turns off from a completed burn cycle.

I've replaced the thermocouple which obviously didn't help, and I'm not sure what is going on with it. It almost seems like some kind of an air/fuel issue, or possibly a problem with some sort of limit switch (but I don't this thing has one, or atleast its not obvious). In the Fury series there is something called the "gaurdian system" which I suspect is the source of my troubles, but I am not sure how it works other than shutting things down if the air/fuel mix isn't right.

"Guardian System™ - One-of-a-kind air/fuel shut-off device offers double protection, maintenance free - no filter to clean, standard replacement parts."

Anyone know what would cause this behavior off the top of thier heads? I'm a little confused as to what is causing this especially because there really isn't a whole lot to this system.


NStone79 is offline   Reply With Quote
Old 01-09-2010, 04:09 PM   #2
Solutions (handyman)
Join Date: Apr 2009
Location: Central Alberta Canada
Posts: 391
Rewards Points: 364

Check the thermal couple again to make sure the pilot flame is in contact with it. If the flame isn't warming the sensor (thermal couple) properly the reading is not accurateand the fuel is closed off. Other than that, call Rheem and ask directly. Most heat units (water tanks & furnaces) have a built in safety feature that closes the fuel if the unit isn't working as it should.


Mark Harvey is offline   Reply With Quote
Old 01-09-2010, 05:49 PM   #3
as seen on tv
Join Date: Mar 2009
Location: pa
Posts: 205
Rewards Points: 150

dirty pilot assembly
qbert is offline   Reply With Quote
Old 01-10-2010, 02:32 PM   #4
Join Date: Jan 2010
Location: Cincinnati, OH
Posts: 3
Rewards Points: 10

Thanks for the quick responses. I have little doubt that the thermocouple is in the sweet spot and is functioning correctly. There was really little to no difference in behavior once I swapped out the thermocouple, despite the fact that the old one had a layer of soot on it.

Dirty valve is definitely a possibility, but is there anyway to test for this? Are the valve assemblies servicable? It clearly has screws on the front and appears that it can be opened.

Also another factor here is that there is an intake duct running down the side of the water heater which dumps on the floor right next to the heater intake. I thought a draft was possibly knocking the pilot out but I've successfully ruled that out. One thing I was wondering... Right now it is anywhere from 5-25 degrees outside; has anyone ever seen an intake duct let in so much cold air that it cools the thermocouple to the point of causing it to kick off? This seems unlikely, but none the less a possibility.

Another thing I have discovered is that the heater appears to work properly, or atleast keep the pilot lit much much longer when the water temp knob is set at about 25% or less. Not sure what that implies but I believe it indicates that there is some sort of air intake issue when the temperature gets cranked up. Any ideas on this one? Could this also be a dirty valve?
NStone79 is offline   Reply With Quote
Old 01-10-2010, 07:04 PM   #5
An old Tradesmen
Join Date: Oct 2008
Location: Somewhere
Posts: 34,421
Rewards Points: 7,832

Probably either a bad gas valve.
or the thermostat is covered with crude. And not able to sense the water temp quick enough. And then over heats the water. And the ECO shuts everything down.
beenthere is online now   Reply With Quote
Old 01-10-2010, 07:12 PM   #6
JohnH1's Avatar
Join Date: Jan 2009
Location: Chicago, IL.
Posts: 428
Rewards Points: 250

I was just talking to one of our tech's today about one of these heaters. He sead he could see insulation through the air inlet holes in the side of the unit. I would not think the insulation should be blocking the holes. Has anyone ever seen the insulation slip down? Maybe this could be a simmiler problem.
JohnH1 is offline   Reply With Quote
Old 01-10-2010, 09:01 PM   #7
Join Date: Jan 2010
Location: Cincinnati, OH
Posts: 3
Rewards Points: 10

Aha! I think that may be the the issue. I was just reading about something similar to what you are describing, and that scenario seems to fit all the clues.

Around here we have very hard water, roughly 300ppm (measured by me, not an actual lab analysis), and I suspect there are Calcium & Mag. deposits collecting in the bottom of the tank, especially considering the quarterly drain a couple gallons routine hasn't ever been performed.

Next question is... do hard water deposits = get a new tank??? Or could I possibly; dump in some CLR, agitate, and drain repeatedly to help remove the deposits? Or is there another way to do it?


Er... wait a minute. Isn't the temp limit sensor a one-time use deal, where it has to be replaced once tripped???

JohnH1: I did notice there was a good amount of visible insulation around the interior access door. I didn't think anything of it, I just presumed that it extended all the way down to insulate the burn chamber as well. While I could have insulation that has slipped down, I don't think that could be causing my issues.


Last edited by NStone79; 01-10-2010 at 09:05 PM.
NStone79 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Low hot water pressure crebive Plumbing 38 02-26-2013 12:26 AM
Water connections for new water heater diggerdave Plumbing 16 03-16-2009 10:36 AM
Gas Hot Water Heater - Help? MaximumAsh Plumbing 22 03-13-2009 10:57 AM
Water Heater Problems martyshel Electrical 4 01-24-2009 12:07 AM
Water Heater tsmith Plumbing 10 12-01-2008 06:24 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1