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Pitsch Plumbing
Pitsch Plumbing, State Certified Plumbing Contractor
Category: Plumbing
Satisfied Customers: 370
Experience:  25 years in the trade. new Construction, remodeling, repairs ect. Business owner. 2nd gen plumber
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replacing control valve on A.O. smith water heater FGR 50 236 existing

Resolved Question:

replacing control valve on A.O. smith water heater FGR 50 236
existing valve: part# XXXXX (new # XXXXX A= 2 1/2", 1/2" psi, nat reg 3.5"
can I install the following slightly different valve:
part # XXXXX (new # XXXXX A= 2 5/8", 1/2" psi, nat reg 4"
Thanks,
Eric
Submitted: 7 years ago.
Category: Plumbing
Expert:  Pitsch Plumbing replied 7 years ago.
Chat Conversation Started
Pitsch Plumbing :

Hello. Give me just a minute to look up you heater.

Pitsch Plumbing :

Actually that unit came stock with a 180193-4

Pitsch Plumbing :

Anyways, yes you can, you can even go with a unitrol that has adjustable pilot. But to answer your question. Yes, it will be fine.

Pitsch Plumbing :

The A measurement is the shaft length, so 2.5 to 2 5/8 is fine

Customer:

so the 'A' dimension being 1/8" longer and the reg setting of 4" rather than 3.5" is OK?

Pitsch Plumbing :

Yeah, the burner tray might sit 1/16 of an inch out, but you also have to understand, that length also depends on how tight the valve is scrweed in too.

Pitsch Plumbing :

The pilot tube and therocouple are soft tube

Pitsch Plumbing :

1/16 of an inch from where it previously was is what im meant to say

Pitsch Plumbing :

We are a warranty station for A.O Smith and have never had an issue replacing old gas valves with new ones

Customer:

does that make sense regarding it being the problem. that is, pilot stays on until temp setting is set to high?

Pitsch Plumbing :

Yes, if its not turing off at the set temp, the therostat has failed.

Pitsch Plumbing :

What the part is called is a combination gas valve ( its the valve and t-stat) in one unit.

Pitsch Plumbing :

or are you saying that when you turn up the temp instead of heating the pilot just goes out.

Customer:

when installing, can i use teflon tape or do i need plumber's paste?

Pitsch Plumbing :

teflon tape is fine, i believe they come with teflon tape already on them. I would also replace the thermocouple while you have it apart.

Customer:

No, when i set the temp to high, the pilot and burner stays on but once the water reaches temp, then when burner shuts down, so does pilot. Pilot works fine when i lower temp to about med high.

Pitsch Plumbing :

Yeah, sounds like the t-stat is failing. When the heater is set to high the water temp should be absolutely scalding hot. 150+ deg. after a while they can go out of range.

Pitsch Plumbing :

Soundslike its thinking its too hot and turning off

Customer:

i am using a valve from a friends relatively new water heater that had a tank problem leak. should i worry that the tank failed because the valve let the water get too hot/pressurized?

Pitsch Plumbing :

is the gas line flexible tube, like copper (supply connected to heater) or hard pipe. ? I wouldnt worry, if that water gets to hot, the T&P should open.

Pitsch Plumbing :

On your friends heater,

Pitsch Plumbing :

Generally, a bad gas valve wont cause a tank to fail

Customer:

flexible copper

Pitsch Plumbing :

ok, then you will be fine, the reason i asked is the new gas valve isnt as wide as the old one so the gas connection is about a 1/2" away from where the old one was, with flexible tube, thats nothing, but with hard pipe it can be a pain

Customer:

Oops, yah it is a hard pipe. Just measured, probably less than 1/4" difference.OK, thanks. XXXXX can get a few more years out of my unit. Can't afford new one now.

Pitsch Plumbing :

Good luck, you should be just fine

Pitsch Plumbing :

If you are satisfied with my answer, please hit accept. :)

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