Rheem Performance Platinum 40 gal water heater pilot won't stay lit

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colvosview

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I have a unit manufactured in 2015 on which the pilot goes out randomly, after working fine for a few days or a few weeks. It has exhibited this problem since it was installed, but for reasons I won't go into, it hasn't reached the top of my "to do" list until now. I don't have experience in this area, but am a reasonable skilled DIY guy. I thought the problem was probably a bad thermopile, which I should be able to replace myself. When I looked for videos to show how to do this, I saw one showing how to test the thermopile, which seemed worth doing before I just replaced it. The test I saw involved pulling off the thermopile connector and bridging the connector with the probes of a multimeter, then lighting the pilot to see if/how much the current increases. I watched the current read out until it got to 650mA, and it was still slowly climbing, so I think the part is OK.

The video technician advised that if the part passed this test, the problem is likely either the thermal cut off switch or the gas control valve. Since I cannot spot anything on this unit that looks like the cut off switches shown on various videos, I'm guessing that that function must be incorporated into the Honeywell gas valve controller, which means that it must be replaced. I thought I would seek advice and/or confirmation before purchasing this somewhat pricey part.

Any words of wisdom from a more experienced practicioner are appreciated!
 

Twowaxhack

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Those gas controls are pure crap.

I’ve replaced more of those in the past 5 years than the prior 30 yrs that I’ve done repair.

Someone should hit them with a class action suit, IMO they’re a defective design and possibly on purpose. They’re expensive too.
 

colvosview

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Thanks for confirming my diagnosis. I'll see where I can find the best price. It seems like a relatively simple job to replace it.
 

colvosview

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I probably should have included the information that when the pilot goes out, there is no error code indicated by the blinking light. It is just dark.
 

Twowaxhack

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I probably should have included the information that when the pilot goes out, there is no error code indicated by the blinking light. It is just dark.
For those valves you have to be present at the time of failure for it to blink a code.

It doesn’t have a memory.
 

Mitchell-DIY-Guy

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Those gas controls are pure crap.
I’ve replaced more of those in the past 5 years than the prior 30 yrs that I’ve done repair.
I've been meaning to ask the pros about that...most of the water heaters I've had in the past 20 years were spark ignition but they were plug-in since they were power vent. The others had the older style gas control, with the pilot, the kind with the black knob on top that you push down, and twist to light the pilot. I know you guys like @Twowaxhack know which ones I'm talking about. The last water heater I had to personally buy was now about 5 years ago.

Today, no matter WHAT kind of water heater brand there is, they all seem to be this white plastic model that is apparently trouble! I guess there is some kind of thermocouple or something inside? I don't think there is a battery, but something must power that flashing light.
 

Twowaxhack

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I don’t believe there’s a battery in them. You have to be present when the malfunction occurs to see the code blink. The thermocouple being heated creates the energy to blink the code.

It’ll throw the code out a couple times then go black.

They have a circuit board in them, a high limit, and they’re plastic where they screw into the tank.
 

BlueSkyHigh

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I had similar problems with a previous gas water heater and had to clean the air inlets at the bottom of the water heater as well as remove the pilot assembly and scrub the thermocouple assembly with fine sand paper. I got a few more years out of it by doing some simple maintenance on it.
 

BlueSkyHigh

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I don’t believe there’s a battery in them. You have to be present when the malfunction occurs to see the code blink. The thermocouple being heated creates the energy to blink the code.
Yep you're correct. I mistakenly thought that there was a long life lithium battery in there but it is a "thermopile", a bunch of thermocouples together, that generate enough power to keep the microprocessor running. Thanks for the tip and the nudge to look into things a bit deeper!
 

colvosview

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Sorry - posted by mistake

I've been meaning to ask the pros about that...most of the water heaters I've had in the past 20 years were spark ignition but they were plug-in since they were power vent. The others had the older style gas control, with the pilot, the kind with the black knob on top that you push down, and twist to light the pilot. I know you guys like @Twowaxhack know which ones I'm talking about. The last water heater I had to personally buy was now about 5 years ago.

Today, no matter WHAT kind of water heater brand there is, they all seem to be this white plastic model that is apparently trouble! I guess there is some kind of thermocouple or something inside? I don't think there is a battery, but something must power that flashing light.
 

colvosview

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I don't see a drip/sediment trap. I can try cleaning air inlets and thermopile, but I'm not optimistic, since this behavior started shortly after the heater was installed. After watching a video yesterday with a clearly explained series of troubleshooting steps, I'm inclined to follow the presenter's instructions to buy a replacement circuit board on eBay. But the ones offered are used, so I'm not sure I'd be improving my situation!
 

TomFOhio

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If that water heater was put in 2015 then you better get ahold of the water heater tec because normally they only have a
6 year warranty. That light works off the thermocouple like twowax said. You will probably have to replace the whole
pilot assembly. I think its all one unit. Get the company called as those parts are expensive.
 
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