Repair leaky White Rodgers gas valve in Attwood water heater

[CaptainLarry]

I know I will bring upon me the wrath of some safety conscious fellows, but I’d like to share my experience repairing the gas valve on my water heater. Try this at home – only if you are a handy fellow.

I'd like to share some photos but I don't want to put them on youtube or whatever.

Last November my brother-in-law noticed the smell of gas outside my camper. We traced it to a small leak at the gas orifice of the water heater. It would burn like a pilot light. I disconnected the line and capped it for a year.

The Attwood GC6AA-10E water heater from 2007 production uses White Rodgers gas valve Attwood P/N 93870, which is now superseded by Attwood P/N 93844. Maybe the replacement part number 93844 is a better design worth buying for $100. I don’t know. See Attwood Brochure.

http://manuals.adventurerv.net/Atwood-Water-Heater-Service.pdf

The 93870 is single stage valve with redundant valves (two valves in series). The White Rodgers P/N is 25M19V-701 – 12 volt, RV applications, -40?-175? F, high sealing force, regulated LP, fixed regulator, encapsulated leads. See White Rodgers brochure.

http://www.emersonclimate.com/Documents/White-Rodgers/sell_sheets/r_4080.pdf

The valve comes apart with ease if you have a special T-15 Torx drive that has the open center. The screws on the unit have a pin that stands proud in the center of the Torx. So a standard Torx won’t do.

Remove the gas valve and cap off the gas line. Remove the orifice and protect from damage. Cap off the inlet/outlet of the valve and clean the outside with a wire brush. Remove the three types of screws holding the valve halves together – 3/8” nut, torx, philips. Remove the two solenoid coils. Carefully split the valve. Don’t bother with the regulator diaphragm but be careful not to get it dirty. Remove the solenoid shafts.

What I found was the valve seats were slightly corroded and the rubber plunger seals were not seating fully. A small layer of scale had built up on the rubber plungers. I scraped off the scale with my finger nail being careful not to damage that surface. Next seal off the gas port leading from the diaphragm with a small piece of masking tape. I then cut a small circle of 220 sandpaper and hot glued it onto a flat screw head. I gently scrubbed the valve seats where the rubber plungers mate. I would use a finer grit if you have it – maybe 400. I tipped the valve on its side and flushed out with rubbing alcohol. When I could see a shiny flat seat I rinsed again and gently blew out with air. Be careful to wash out the passageway between the two valves.

At this point I’d say it is good as new. But how did the corroding moisture get in? Looking at the outside of the valve, the casting is very corroded. I suspect that repeated dousing with hot water during winterizing of the tank may be damaging the valve. I applied a little sealant to the outside of the solenoid cylinders (the metal tubes that the coils fit over) where they pass through the valve body. Otherwise, maybe corrosion is inevitable due to contaminants in the LP.

After reassembly I tested it repeatedly. I only let the gas kick on for a second because there is no water in the tank. No leaks now, but I’ll keep a nose on it for a while to come.

Sincerely, CaptainLarry

[Ka_Ron]

No valve manufacturer in the world has a user serviceable valve.
Not recommended at all. Replace the valve.

[Old-Biscuit]

Having lapped in 100's of valve faces and seats I understand what you have done.

Only problem is although you have a shiny clean seat area it is not flat, properly angled or concentric because of your 'technique'.
The rubber plunger if flexible enough will mate with the valve seat area but may fail/leak due to age, loss of elasticity and imperfect seat area.

Keep close eye (nose) on it when in use........your quick check was too short to prove 'serviceability'.

Much safer to replace with new style gas valve.

[Gdetrailer]

CaptainLarry wrote:
I know I will bring upon me the wrath of some safety conscious fellows, but I’d like to share my experience repairing the gas valve on my water heater. Try this at home – only if you are a handy fellow.

I'd like to share some photos but I don't want to put them on youtube or whatever.


Sincerely, CaptainLarry

I don't blame you for not wanting to post photos, however YOU most likely should not have posted this info at all...

I would hate to see someone get hurt attempting to make same repairs using your post as a guideline...

Valves are replaceable, HUMAN lives are not.