Water heater pressure relief valve

[woliners]

So my old Bowen water heater works great. Haven't observed the problems seen in other posts. However, I noticed the pressure relief valve was leaking around the little handle thingy. I reached in and jiggled it a bit and the handle came right out. Pretty rotted. It really leaked then as one would expect. Well I got the valve system removed without any issues, but I noticed that there is another pressure relief valve at the pipe exit underneath the camper body.

What's that all about. Do I really need 2 valves in series like that or did someone have too many pressure relief valved laying around the garage??

next question: Are these "special" valves or can you get them anywhere?

Bill

[TomW]

Originally Posted by woliners

... I noticed that there is another pressure relief valve at the pipe exit underneath the camper body.

What's that all about. Do I really need 2 valves in series like that ... ?

next question: Are these "special" valves or can you get them anywhere? ...

The relief valve on the water heater is designed to pop open at a certain pressure OR a certain temperature. The settings are usually 150 psig or 210 degF. Plumbing code mandates that valve has to be there.

My '67 Overlander has a pressure relief valve on the cold water line (probably the other relief valve you noticed). At first, I considered it's presence the mark of superior design .i.e. one could do without it, but on occasion it might be useful.

But, I noticed that valve dribbles a little bit when water is heating (heating water raises the pressure in the line). So the valve serves a constantly useful purpose.

Airstream used a cold water relief valve rated to vent at (IIRC) 60 psig. Hardware store models are rated at 90 psig. InlandRV sells an Airstream-approved cold-water replacement.

I think you should keep both relief valves.

Tom

[woliners]

Hi Tom, Thanks for the reply. Actually, the second valve is attached to the end of the pipe coming out of the first valve. (they're in series) The exit pipe from the first water heater valve is routed out the bottom of the camper. Attached to the end of this pipe is another pressure relief valve.....sticking out the bottom of the camper and that's where it terminates. I don't have any attached to the cold water pipes....I should probably install one.

[Fyrzowt]

I had the same question a while back, the thread is below...
I have the same set-up as you - you'll see in my thread (IIRC) that there was some confusion about what valve I was talking about.
Replace the valve that broke, leave the other one.
Dave

http://www.airforums.com/forums/f445...lve-28019.html

[woliners]

Thanks Dave,

I think I'll do that....why tempt fate. By the way, both valves are shot. The little manual lever just popped out of both of them.....and they both ooooz a steady stream.

[Excella CM]

I can't see any justification for a second valve in series with the water heater safety valve. It's one more thing that can stick and over-pressure the heater. It can also mask a failure of the first valve. If you think AS put it there, ask them why.

[woliners]

Hey Everybody,

Thanks for the input. Lotsa good discussion. I've run the thing for a few days now and everything checks out. I probably won't max out the temp setting on the heater just to leave a little buffer there as well. I'll keep an eye on it. If anything big happens.....I'l let ya know.

Thanks,

Bill