I believe my hot water heater has a bad thermocouple. I went to start to replace it, and it has a sealed combustion chamber. I removed the 4 screws and tried to take off the cover. It didn't budge. Am I just not trying hard enough? I am afraid I am going to break something else in the process. I am a novice handyman, but everything I have read says this is a an easy fix. The hot water heater is a Rheem Ever Kleen.

They make a lot with that title Rheem Gas Water Heaters which one is yours? Lets start by talking about why you think your thermocouple is bad, what's happening? BTW after removing the screws you may need to pry the corner of the door with a flat screw driver

The model # is 42VR50-40F. The pilot went out yesterday. We were able to relight it and it stayed on for about 6-8 hrs, then went out again. When we tried to light it it just kept going out. We follwed all the directions, but it didn't stay lit.

I did try prying it with a screw driver, but was unsuccessful. It seems to be pretty stuck. If I pry really hard can it damage anything? Is their something besides the 4 screws that needs to be loosened?

I agree with your thoughts about just replacing the thermocouple, cheap and normally easy. Any luck with that flast screw driver?

Use a large flat blade tool like a putty knife and gently work around the perimeter of the access cover, without bending it, till the cover pops loose. LIGHLTY tapping the edges of the cover with a small rubber mallet may also help to loosen it. Between the cover and the burner housing is a high-temp rectangular silicone gasket that seals the chamber. Over time, things kind of stick together. NOTE: the new thermocouple set up should include a new gasket. Rheem instructions indicate that any time the burner access door is removed, the gasket must be replaced. THe gaskets are available on line, and plumbing stores. I got mine at Menards. They sell Richmond water heaters which are Rheem heaters branded for consumer purchase. I confirmed this with a service rep when inquiring about some parts.

Thanks, I will try that. Can I get the gasket at Lowe's or Home Depot or will I have to go to a plumbing store?

The gaskets should be available at any plumbing supply. Home depot and Lowe's don't sell Rheem/Richmond, at least in this area, so they wouldn't have it.

In case u don't see it below, the gaskets should be available at any plumbing supply. Home depot and Lowe's don't sell Rheem/Richmond, at least in this area, so they wouldn't have it, unless the gasket fits several brands.

No plumbing supply store here had the gasket, so they ordered it and it should be here Friday.

Kyleleaann...

Good that the gasket/screws have been ordered, but did you gain access to the thermocouple for replacement? I'm betting, not!

If not, that is probably because with these newer heaters you need to remove the combustion chamber door and unscrew the thermocouple, the pilot tubing and the gas supply tube from the gas valve.

Here, you could try to remove the thermocouple with everything still in place, but it really turns out to be a super easy job if you disconnect everything from the gas valve as the whole burner assembly (including the burner) will simply pull out as one unit... see image... ;)

Replace the thermocouple and install the gasket per manufacturer's instructions.

Questions? Let me know...

Mark

Very good point, I had an apparent brain cramp and totally forgot about disconnecting the lines from the gas valve, though mine still required some prodding with a screwdriver...

Thanks, we did pull out the whole assembly, changed the thermocouple and still the pilot won't stay lit. Any ideas?

Try this...

Leave everything connected to the combustion door, but loosen the combustion door and pull it forward an inch or so being sure to confirm a good 1/2" gap or so all around the door to let lots of air in, OK?

Now, light that pilot again and leave everything, including the door open for now and see if that fixes your issue. If the pilot stays lit then you have a make up air issue and the filters and the combustion chamber vapor system will need to be cleaned properly.

Try this test... let me know what happens.

Mark