My 8 year old water heater decided that it does not want to produce hot water anymore late last night.

No leaks (knock on wood), but I am getting a 7 blink flash out of the status light on the gas control valve which according to the decoder means Gas Control or Valve Failure.

Pilot will turn on and light but will not stay lit once pressure is removed from the pilot valve.

I disconnected the pilot, burner feed, ignitor wire and thermopile and cleaned off a few rust flakes from off the top of the burner and blew everything off with some compressed air and reassembled. No improvement.

Before I replace this water heater, does anyone know how to reset this control? Figure I'd try that before I throw in the towel.

Relevant model numbers off the side of the gas control unit:

WV8840C1604

AP16613B-1

Anyone have any bright ideas?

Thanks

If the unit sets without a pilot, no voltage will be available for the GV. Therefore, normally resetting it. They want you to turn it to the off position. But, simply put, no power is no power regardless of where the manual valve is placed.

First thing you want to do is check the over temp sensor. Making sure its NOT open. Should be fine since the control will power up and give a fault code.

Then you want to measure the thermocouple's output.
Unscrew it from the valve. Connect a multimeter to the outside copper tubing and the center conductor. Light the pilot, while holding down the button and see what it's generating. Up to 30 MV is normal. Anything under say 15, replace it.

I imagine the output will be fine. If so, the gas control is bad. There has been issues with this exact valve.
More than likely, the circuit board inside the control is bad.

It's simple to replace, without the need to drain the tank.
And is what I'd do before replacing the whole water heater.

If you'd like further instructions, email your phone number.

Make, model and serial of the water heater will also help.

quote:

Originally posted by Excam_Man:
If the unit sets without a pilot, no voltage will be available for the GV. Therefore, normally resetting it. They want you to turn it to the off position. But, simply put, no power is no power regardless of where the manual valve is placed.

First thing you want to do is check the over temp sensor. Making sure its NOT open. Should be fine since the control will power up and give a fault code.

Then you want to measure the thermocouple's output.
Unscrew it from the valve. Connect a multimeter to the outside copper tubing and the center conductor. Light the pilot, while holding down the button and see what it's generating. Up to 30 MV is normal. Anything under say 15, replace it.

I imagine the output will be fine. If so, the gas control is bad. There has been issues with this exact valve.
More than likely, the circuit board inside the control is bad.

It's simple to replace, without the need to drain the tank.
And is what I'd do before replacing the whole water heater.

If you'd like further instructions, email your phone number.

Make, model and serial of the water heater will also help.

Thanks. This unit is a Rheem XG50T09HE40U0, which may be a Home Depot only P/N. Nothing comes up when searching that model number on the Rheem website. It's a 50 gallon natural gas unit.

Watched lots of YouTube videos on this issue today and didn't see anything that look sane, relevant or worth trying. I've left it off and tried after a couple hours to no avail. Tried max hot for 10-15 seconds, hot for 10-15 seconds and pilot for 10-15 seconds per something I found online that said it may help with this issue and didn't. Saw something else about actuating the valves with a 9V battery, another about rubbing the circuit board down with a piece of aluminum foil to ESD it into some kind of resent supposedly.

This unit does not have a traditional thermocouple, it has a two wire thermopile.

Like you, I presume the thermopile works as I do generate enough voltage to get the status light to turn on.

The other issue is that even if I can prove the control unit is bad (likely), or the thermopile is bad (seems unlikely) I can't get either one local until Monday-Tuesday at the earliest and the control valves are 1/2 the price of a cheap water heater.

Have not been able to turn up a P/N for the control board yet. Looks like lots of P/N supersessions on these and can't find a chart to decode them. Also looks like the OEM P/N and field service P/N's might not be the same either.

This was the best I could find to poke around on: https://customer.resideo.com/e...0&catpath=1.2.7.6.16

Bonus info, I don't plan to live in this house more than another 12 months or so but we do use quite a bit of hot water, so a fast, long-lasting fix is becoming paramount over cost. A new water heater might be a selling point too.

Awe, a fucking Rheem.. can you tell I like them?

It has a 2 yr full warranty, plus 7 additional yrs for the tank and controls. So a call to Rheem might benefit you.

Yes, the C valve (unlike the A) is a thermopile version. 350 MV minimum to 850 max.

Rheem has TRD, a safety system which will close off combustion air. Instead of a normal TCO device (again A valve)

You won't find a number for the board, as it doesn't exist as a replacement part. Honeywell considers the whole gas control to be a non-serviceable item. Therefore, replacement of the complete control is standard procedure.

However, you can replace parts of the Honeywell ICON valve, if you have a correct replacement valve handy.

***
The WV8840C1406 was discontinued June 23, 2020
Its replacement is # SP20832E
https://www.supplyhouse.com/Rh...s-Control-Thermostat

Make sure to test the thermopile first, before ordering a new control.

Serial numbers also help.
I know of a model which has 24 different pilot assemblies, depending on serial number.

***striked due to switched numbers

This message has been edited. Last edited by: Excam_Man,

quote:

Originally posted by Excam_Man:
Awe, a fucking Rheem.. can you tell I like them?

It has a 2 yr full warranty, plus 7 additional yrs for the tank and controls. So a call to Rheem might benefit you.

Yes, the C valve (unlike the A) is a thermopile version. 350 MV minimum to 850 max.

Rheem has TRD, a safety system which will close off combustion air. Instead of a normal TCO device (again A valve)

You won't find a number for the board, as it doesn't exist as a replacement part. Honeywell considers the whole gas control to be a non-serviceable item. Therefore, replacement of the complete control is standard procedure.

However, you can replace parts of the Honeywell ICON valve, if you have a correct replacement valve handy.

The WV8840C1406 was discontinued June 23, 2020
Its replacement is # SP20832E
https://www.supplyhouse.com/Rh...s-Control-Thermostat

Make sure to test the thermopile first, before ordering a new control.

I wasn't real thrilled when I put it in back in 2014. However, it was what I could get "right now" that fit in my existing spot with a minimum of pipe reconfiguration required.

Can you confirm the P/N? I have a 1604 not a 1406.

I'll be sure to dig out my Fluke and check the thermopile before I pull the trigger on anything.

Draining the tank down now.

Thanks.

quote:

Originally posted by M1Garandy:
Can you confirm the P/N? I have a 1604 not a 1406.

I'll be sure to dig out my Fluke and check the thermopile before I pull the trigger on anything.

Draining the tank down now.

Ooops.. my bad.
What's your serial number?

BTW, You don't want an empty tank, when you light the pilot to check the thermopile.

RHLNQ351442973.

I figured the pilot on an empty tank would not hurt anything in the minute or two it took to check the thermopile, but I can add a little water back to the tank before I do if that is a better option.

quote:

Originally posted by M1Garandy:
RHLNQ351442973

There we go, that makes life easier...

Rheem's original part number for the valve was AP16613B-1
Replacement is # SP20832B

https://www.supplyhouse.com/Rh...s-Control-Thermostat

quote:

Originally posted by Excam_Man:

quote:

Originally posted by M1Garandy:
RHLNQ351442973

There we go, that makes life easier...

Rheem's original part number for the valve was AP16613B-1
Replacement is # SP20832B

https://www.supplyhouse.com/Rh...s-Control-Thermostat

Thanks. Out if curiosity, where are you finding this info? Rheem would not find me anything for my model or S/N on their website and could not turn up a parts list either.

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