[dstratto]

Can you replace aunitrol gas water heater valve with a robert shaw valve?

[massplumber2008]

Hi Dstratto

If this is a water heater with a closed combustion chamber then the gas valves may NOT swap out as the gaskets may not give a gas tight seal between manufacturers tubing or other similar kinds of issues. You would need to call one of the manufacturers to proceed here.

If you have an older, open combustion chamber water heater then as long as the thermocouple port, the pilot tube and the gas supply tubing all line up the same way (they should) I see no reason you can't swap out one for the other.

Just be sure that the replacement gas valve is rated for similar BTU input and that there are no extra ports/wiring connections, etc. and it should work fine... ;)

More questions just let me know, OK?

Mark

[Terry 99]

Swapped out a New Gas Valve for my brothers old Hot Water Heater.
The Pilot Light wouldn't stay on.
Changed the Thermocouple.
Still won't stay on
I'm thinking, is it because the new gas valve is set up for a Ignition Switch or do I have a new defective gas valve and thermocouple?

[todda1]

If I have two water heaters connected together and I need to replace the gas control valve, is there any issue of syphoning water from tank 2 when draining the water out of tank one?

[massplumber2008]

Hi Todda

Are the water heaters piped in parallel of in series?

If you have a vacuum relief valve (VRV) installed at each water heater then there should be no issue at all.

If you don't have a VRV then I suppose, theoretically, you could siphon off the other tank, so I would recommend opening a hot water faucet (on a two handle faucet) and I would also probably open the temperature and pressure relief valve (T&P valve) on both water heaters!

That will guarantee no siphoning. Be aware, however, that once you disturb the T&P valves they may not reseal and may need to be replaced! Rest assured that if this is necessary they are real cheap ($10.00 each) and easily replaced!

Good luck!

Mark