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jcb
Hot Water Heater Emergency Temperature/Pressure Valve replacement

I watched ask this old house and they said you have to test your emergency t/p valve once a year. I never knew that before. When I tried it, it was hard to open and then after it let it close, it started to leak just as Tom said on the show. Luckily, it is only about a $15 part that is pretty easy to replace though there is more water in the top of the tank than I thought and I made a bit of a mess. Even though I've never had a water tank explode, I feel better knowing that this relief valve is working properly.

Thanks!

dj1
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

Your concern is justified.

Have you successfully replaced your temp & pressure valve?

johnjh2o
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

I have been around for a long time and I don't understand just what this test is trying to prove. In over 50 years I have never seen a relief valve that didn't open when lifting the lever but I have seen many that once opened they don't reseat. Just how would this test prove it's not in working order? I wish I had a nickel for every relief valve I have changed because someone decided to opened it.

HoustonRemodeler
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

What John said plus;

1- I have seen ancient and new T&P valves blow when needed. I have never seen an exploded water tank. The valves do their jobs well.

2- Is your T&P valve piped to a safe location so when the valve releases it doesn't flood the house or burn anyone?

junkout
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

it is not really a test. the idea is to open it every so often to make sure it doesn't seize up. also if you open it regularly it wont leak after you close it. there was a water heater that blew near us about 8 years ago and it blew the from wall of the two story house off the foundation. it doesn't happen often but when it does it is bad.. the reason is that both the high limit switch and the relief valve both have to fail which rarely happens but it can so why not just open the valve occasionally to be on the safe side

JLMCDANIEL
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

Periodic opening lets water get up in the T&P valve, evaporate, and leave deposits. Those deposits is what can cause a valve failure.

Jack

dj1
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

A true horror story:

A "plumber" replaced a large water heater in an apartment building in Santa Monica a few years ago. The new water heater came without a T&P valve, so he plugged the hole tight. Subsequently, the water heater blew up very shortly after that, killing 10 tenants.

Moral of the story: don't tamper with the valve and make sure it works properly.

Mastercarpentry
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

I've seen the results of a water heater explosion and it ain't pretty. Then again that is just one instance in millions of homes which I've seen so.......should you worry about it? That's up to you. I do test mine annually to be sure it's not seized and I replace older ones as a matter of habit as some years ago there was a huge recall of these by the major manufacturer of US T&P valves as they would not open properly. Most of those will be gone in another ten years so it's up to you whether you want to worry or not. Of the T&P valves I test, maybe 1 in 10 leaks afterward. As cheap and easy as replacing one is I go ahead and test, I'd rather have one I know I can trust than a maybe, especially knowing how my luck (or more appropriately the lack of it) goes!

Phil

johnjh2o
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

Lifting the lever and opening the valve doesn't tell you that it's working. All you are doing is opening the valve manually. That doesn't tell you that it will open with excessive temperature or pressure. If your concerned that it may not be working then replace it.

dj1
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

T&P valves go for less than $10. Changing a suspected valve should be a non-issue.

HoustonRemodeler
Re: Hot Water Heater Emergency Temperature/Pressure Valve replacement

I did a google image search for exploded HWH's and found only one. If this were a more common occurence, there would be many many more.

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