Are there instructions for replacement of thermal coupler for gas water heater with closed system with only a window to see the pilot light. Looks like there are screws to take apart the area of the burner.

Here you go. Good luck

How to Replace a Gas Water Heater Thermocouple | eHow.com

On some new water heaters, you can't replace just the thermocouple, but need to replace the complete pilot tube,sparker, thermocouple assembly. Others, you can still just replace the thermocouple by itself. What brand is your water heater, and what are the model and serial numbers?

You may need to call a pro for this one. Your FVIR (Flammable Vapor Ignition Resistant) hot water tank is different than tanks of old. Most require a manufacturer supplied part or parts and may include removal of the burner assembly, disconnecting gas supply from control valve, new gasket seals and updated or retrofit parts. I'm curious how you determined that your thermocouple is the issue. Your FVIR tank may have a combustible gas sensor that tripped or the control valve may be bad. As I said, call a pro or if it is under warranty you may call the manufacturer for further action. The most important thing to remember is do not try to rig it to get by temporarily. With the safety features it should be impossible to rig, but even trying could be dangerous when dealing with gas.

Instructions are not for FVIR tanks.

Hi guys...

Hard to say if this is a thermocouple issue with the new heaters nowadays... ;) Exactly what issue(s) are you having Keith... could be vapor sensor, could be air make up issue... let us know?

To replace a thermocouple with the newer closed combustion chambers you need to disassemble all the tubes from the gas valve and then remove the burner door and gasket.

You'd then replace the thermocouple and install a NEW DOOR GASKET before installing the door and reconnecting the tubes to the gas valve. This is required to keep the safety features in place.

The gasket kit can be ordered from the manufacturer of the heater or may be available at a local plumbing supply store, OK?

Questions? Let us know...

Mark

Sorry PGHPLUMBER...was posted at same time as you!! Good post!

massplumber2008 - The exact problem if I can explain it is at the first discovery of the problem was that I found the pilot light was out. I restarted the pilot light, then turned on the thermostat as normal, at that time the burner went on as normal and heated the water. What is happening is after the water is heated and the burner stops the pilot light also goes out. Later I can re-light the pilot light (has an auto striker) and turn to on and the burner will then again heat the water OK. Then when it is heated and the burner shuts down, so does the pilot light. I have a Rheem Guardian 40 Gal water heater. The Model # is 22V40F1, Manufactured 3/2006.

If it was manufactured in 2006 it would be best to call the manufacturer to see if a warranty applies. Most do not after 1 year, but it never hurts to ask. Even we plumbers rely on the manufacturer to supply us with answers because of so many differences in appliances these days. Also, if there is a history of issues that would indicate a defect the manufact. Would have a record of it. Recently the same situation that you described occurred in a customers house. Same symptoms with the pilot so I called the 1-800 number on the spot. They stated that the gas control valve was closing completely when the thermostat was satisfied and if the thermal coupler was bad then it would never initially lit. Best bet to be sure is to call them. Have model and serial number handy.

As I have stated in the past and will again in the future; if a job seems to be too much for you or could create an unsafe situation for you, call a professional. There are many things that an on-site inspection could reveal when assessing a problem and an online diagnosis may get you pointed in the right direction, but may not be a guaranteed substitute for a service call.
Additional tip: Check the drafting of your flue pipe with a match. Light the match and hold next to flue at top of tank. Flame should pull towards the inside. Blow out the match while still in position to see the smoke follow the same flow path through the flue. Carbon monoxide detectors are just as important as smoke alarms. If you don't have them, get some. Follow manuf. Install instructions as to best locations to mount and test routinely with your smoke detectors.

Thank you for the good advice.
keithlm

You Guys have some great information. I have ordered a Thermal coupler kit and also just today I did contact Rheem and they are going to send me a new Thermostat. They seem to think that is the problem. I guess I will start with the Thermostat 1st.

Thank you, I will let you all know how it turns out it will be probably Tue or Wed by the time I get the parts.

If Rheem thinks the thermostat (gas valve) is the issue then replace that, for sure! Most likely the issue here... ;)

Let us know the result!

Mark

Hello all from keithlm; I got a new thermostat/gas regulator from Rheem. It was under warranty so they didn't charge me. My Grandson & I drained the tank took out the old one and installed the new one. It looked different but all the connections fit. I used a thread tape exclusive for gas to be safe. Then I checked for any leaks with soap & water mixture. All was well. As you recall my first thought was that it was the thermal coupler, but that was not the problem. I appreciate all the good input from you all. I do have a thermal coupler now that I didn't need but will keep it just in case some day the T-coupler does indeed go bad. Rheem sent a step by step instruction sheet which was helpful. Thanks again all.

Hi Keith...

Thank you for taking the time to follow up on this. We appreciate it!

Mark