[shamer81]

My pilot light has a crisp blue flame when I light it and stays that color, but it will not stay lit. I have no problem lighting it, and then it takes off, but then it will go out after an hour or so. So, is this the thermocoupler?

[afaroo]

It sounds like problem with the thermocouple, First check the connection for loosenss, tightend the nut at the valve about 1/4 of a turn and try if it will help if not,then you replace the thermocouple it is cheap to buy and is easy to replace, good luck.

John

[massplumber2008]

Hey Shamer...

Try tightening the connection from the thermocouple to the gas valve... say 1/8th turn or less... just snug it up (don't overtighten). If this then continues then may be good idea to change the thermocouple.

How old is heater?

Let me know...

MARK

We almost got that one word for word... huh John... :)

[shamer81]

I think that the heater is original to the house. 11 years or so. But the pilot has an electric ignitor is and closed off, I have to view it through a small window.

[massplumber2008]

Hey Shamer...

If you have a closed combustion chamber then it is possible that a VAPOR switch is cutting out the pilot... This can be due to a few things, especially excess condensation, or it could simply be an older, defective vapor switch.

If you have a closed combustion chamber (need to remove screws to remove door to combustion chamber) then you could try to bypass the vapor switch by connecting the two wires that run to it together... temporarily.. see if that helps!

Check out the instruction booklet that usually hangs from the heater (if present) and do a quick read through the troubleshooting section. Otherwise, get us the name of heater, the model number and the serial number... see what we can do here.

If this is not a closed combustion chamber let me know.

MARK

[shamer81]

My thermocoupler runs down to a small black circlular disk, then continues on with the copper wiring. Some people at the local Ace hardware said that it is a temperature switch. I have tried to bypass it and I'll see if that works. I don't know if that is the vapor switch that you were talking about. The guys at yhe hardware store also said it might be worth it to replace the hot water heater because it is about 11 years old. It is a Reliance 606. Model number 640XORT. SN-C04226584.

[massplumber2008]

Shamer... have you checked the filter /screen at the base of the heater.. If this screen is clogged this could reduce air for combustion and could cause issues with pilot lighting.

And sounds like a CLOSED combustion chamber (you did not confirm this for me?. does combustion door have screws? ). If this is the case then I doubt it is the thermocouple here... more like the thermal switch (outside combustion chamber)... or could be flame arrestor issues from inside the chamber (combustion air issues).

Check out this link:

http://www.reliancewaterheaters.com/...186486-002.pdf

This should be your heater exact, or may be newer model. Let me know.

Scroll down to page 31 of 36 for pilot troubleshooting. As I worked it out, the gas valve is gone (internal sensors)... and since heater is 11 years old... may be best to replace the unit.

Let me know what you think...

MARK

[letmetellu]

After you light the pilot and it is the pretty blue flame that you described, what does it look like through the glass window after you turn the gas to on? Does the water heater burner burn a pretty blue flame or does the entire inside of the chambe look like a yellow flame, and the flame tips are not pointing up from the burner but dropping down?

The Relianse water heater of that age has a cordite disc in the bottom of the heater, with hundreds of very small holes in it, this is what make it a explosion proof heater ( So they say, I am not convienced yet). I think that yours is covered with dust and lint.

If you will take off the black filter a the bottom side of the water heater you can use a very flat long handle brush to brush the lint and dust off this inside filter. After you brush it off you can use a vacuum to suck all of the lint out.

Another way that I have do it is to disconnect the vent pipe from the top of the heater, and then connect my shop vac to the top of the heater. I use duct tape to make it stay and to make it air proof. Now turn on the shop vac and blow the dust out the bottom of the heater, at the same time you another vac to suck the dust out the bottom.

If this works for you please let me know.

My pilot light has a crisp blue flame when I light it and stays that color, but it will not stay lit. I have no problem lighting it, and then it takes off, but then it will go out after an hour or so. So, is this the thermocoupler?

Did you ever find out for sure what was wrong with your water heater?