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 > Check pressure Relief valve ??

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sunline1

Northeastern Pa

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Posted: 09/17/08 12:54pm Link  |  Quote  |  Print  |  Notify Moderator
Is there a way to check the pressure relief valve on your hot water heater ? It's and Atwood hot water heater if it makes a difference. I don't know the manufature of the pressure relief valve.

Is there a way to test it to see if it will release at the correct pressure and or temp if that's the case. Any info appreciated. Thanks

Sunline1

MAJESTYPOINTERS

MONROE, MI.

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Posted: 09/17/08 01:11pm Link  |  Quote  |  Print  |  Notify Moderator
The only way I can think to test one....If it is truly heat operated..... would be to take it out and put it in water on a stove. Use a temp gague and see if it comes open at the right temp similar to testing a thermostat.
I am not shure but some may be presure activated. Those would be harder to test. Would require compresser and plumming and fittings.
If I am right they don't cost that much. If you have a question about one maybe it would just be best to change it out. JMO

Bonefish

Midland, TX

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Posted: 09/17/08 01:20pm Link  |  Quote  |  Print  |  Notify Moderator
The only instructions on them is to flip the lever to make sure it moves freely and water comes or they are not stuck. With water pressure on be careful if it has been on and is full of hot water. I usually belch mine when filling up the hot water heater.
Bonefish




mike4947

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Posted: 09/17/08 02:15pm Link  |  Quote  |  Print  |  Notify Moderator
These are generic and basically idiot proof. They are designed so if they do ever go bad they leak/open.
BUT, leaking in most cases does not mean the valve is bad. RV systems are sealed so any increase in temperature such as the water heater provides create pressure and expansion of the water. Unlike home water heaters, RV water heaters are designed with an air pocket that can compress when the water heats/expands. This air can be absorbed over time and the valve will weep when the water heats up as it senses the expansion/increase in pressure. The cure is to partially or fully drain the water heater and refill this will create a new air pocket.
Areas with extremely hard water may over time if you use the relief valve in draining the water heater may build up calcium deposits on the sealing surface and cause weeping as well. In that case rather than trying to clean them off we replace the valve.
Believe it or not it's the same valve used on home hot water heaters. That's how generic they are.

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wa8yxm

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Posted: 09/17/08 02:43pm Link  |  Quote  |  Print  |  Notify Moderator
I agree with Mike.. Far as I know the things have only one or two fail modes and in either case (Slow or fast leak) you will know it and not need to test

The only way to test pressure release is to increase pressure. put a gauge in the line and start increasing the pressure.. Sooner or later one of 3 things will happen

1: The TPR starts to pass water (Note the pressure)
2: The seals in your toilet give way and flood the bathroom
3: A fitting elsewhere gives way and floods your rig

I do not suggest using this method of testing

Nothin adds excitment like something that is none of your business
Kenwood TS-2000 housed in a 2005 Damon Intruder 377


ozman

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Posted: 09/17/08 03:16pm Link  |  Quote  |  Print  |  Notify Moderator
mike4947 wrote:

These are generic and basically idiot proof. They are designed so if they do ever go bad they leak/open.
BUT, leaking in most cases does not mean the valve is bad. RV systems are sealed so any increase in temperature such as the water heater provides create pressure and expansion of the water. Unlike home water heaters, RV water heaters are designed with an air pocket that can compress when the water heats/expands. This air can be absorbed over time and the valve will weep when the water heats up as it senses the expansion/increase in pressure. The cure is to partially or fully drain the water heater and refill this will create a new air pocket.
Areas with extremely hard water may over time if you use the relief valve in draining the water heater may build up calcium deposits on the sealing surface and cause weeping as well. In that case rather than trying to clean them off we replace the valve.
Believe it or not it's the same valve used on home hot water heaters. That's how generic they are.


Thats it. Couldnt have said it better.

nbounder

Arizona mountains

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Posted: 09/17/08 08:41pm Link  |  Quote  |  Print  |  Notify Moderator
One small addition - when you test it manually, close it while water is flowing. The rinse action will tend to clean off any embedded debris on the shut-off seal.

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