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T&P Valve

I've replaced my T&P valve twice now and it still keeps blowing off. Can anyone tell me why this is happening? Is my water heater worn out? It's only eight years old. I've lowered my water temperature and am not sure that I have too much pressure. This is confounding me.

Re: T&P Valve

I just went thru the same thing a few months ago. My problem wasn't the temperture side of the pop off valve. It was the pressure side. You need to check the pressure going to the tank. My incoming pressure was 140psi and it was spiking over 150 that is when my would pop. I had to install a new presure regulator because my old one had quit working properly. That solved my problem.

Re: T&P Valve

Thanks Mike. I'll be sure and get that checked. I'll have my pressure checked at the meter and work from there.

Re: T&P Valve

You might also need an expansion tank. W/H's can build up astonishing heat and pressure when thing's aren't right, and many building codes now require expansion tanks to prevent this problem. I do recall seeing a TOH episode dealing with the same issue so you probably need to watch more television too!

FYI: Several years ago there was a recall of certain AO Smith manufactured T&P valves. They are one of the largest suppliers of T&P valves in the US so be sure your T&P valve(s) aren't one of these. They were also rebranded by some suppliers and sold under a different name. Smaller stores may still have some of these stocked on their shelves; the info you'll need to check is on the attached tag. The major outfits have long ago caught the suspect units and returned them.

Let me say here that AO Smith is one of the most respected names in the business and for good reason. Sometimes even the best of us has unwanted problems develop; we're only human!


Re: T&P Valve

Well, dang MC. Much to the chagrin of everyone else in the house, I watch Ask TOH every Saturday and Sunday morning on DIY.
I have a connection at the local water company and they are going to test my pressure first. Appearantly, this is a very common problem here in rural Mississippi.

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