Pressure relief valve?

[Don klassen]

Is this the pressure relief valve on this tank I circled it in yellow? I’ve only seen the prv in the centre of the tank or the side of the tank before . It’s also coming off the cold side. I don’t thing it is the Prv, but what is it and why does it have line running to the house drain?

 

[Reach4]

Recirculation line maybe?

 

[Sponsor]

 

[LLigetfa]

Hot Water tanks use a TPR, not a PRV. Since the TPR has a heat sensor that protrudes into the tank, it is mounted directly to the tank.

 

[Don klassen]

I’ve figured now It is definitely a shutoff valve with a drain with pex going to house drain but what is the cap at the end for?

 

[Master Plumber Mark]

It is just a fancy shut off valve with a thermal release valve built in.. It is supposed to take the place of
a thermal expansion tank....I dont think they work as well and are a cheap ass way to avoid the expense
of installing a thermal tank....

Your pop off valve looks to be in the dead center --middle of your heater on the top... it does not appear
to have a pipe directing the flow of water over the side of the heater to the floor....

 

[Reach4]

Yes! Zurn Combination Water Heater Shutoff and Thermal Expansion Relief Valve, at least I think it is Zurn, but could be Apollo.

Does the casting say Zurn? Apollo makes similar. https://www.zurn.com/products/water-control/relief-valves/bvecxl https://www.zurn.com/media-library/web_documents/pdfs/specsheets/bv-bvecxl-pdf

Releases water typically at about 125 psi. Down side is that it uses water, and thus it may not be allowed in some places. Upside is that it may last more decades than a thermal expansion tank, plus it is smaller. https://www.supplyhouse.com/sh/control/search/~SEARCH_STRING=BVECXL

 

[Fitter30]

No one should use a pressure relief for expansion devise. Dripping causes mineral build up on the seat and if the valve needs to relieve in honest just might not due to the build up.

 

[Jeff H Young]

just a drain valve .

 

[Don klassen]

It is just a fancy shut off valve with a thermal release valve built in.. It is supposed to take the place of
a thermal expansion tank....I dont think they work as well and are a cheap ass way to avoid the expense
of installing a thermal tank....

Your pop off valve looks to be in the dead center --middle of your heater on the top... it does not appear
to have a pipe directing the flow of water over the side of the heater to the floor....

It is just a fancy shut off valve with a thermal release valve built in.. It is supposed to take the place of
a thermal expansion tank....I dont think they work as well and are a cheap ass way to avoid the expense
of installing a thermal tank....

Your pop off valve looks to be in the dead center --middle of your heater on the top... it does not appear
to have a pipe directing the flow of water over the side of the heater to the floor....

The pop off valve you’re talking about is actually the vacuum relief valve. On further inspection I found the TPR valve on the side of the tank.

 

[Don klassen]

Yes! Zurn Combination Water Heater Shutoff and Thermal Expansion Relief Valve, at least I think it is Zurn, but could be Apollo.

Does the casting say Zurn? Apollo makes similar. https://www.zurn.com/products/water-control/relief-valves/bvecxl https://www.zurn.com/media-library/web_documents/pdfs/specsheets/bv-bvecxl-pdf

Releases water typically at about 125 psi. Down side is that it uses water, and thus it may not be allowed in some places. Upside is that it may last more decades than a thermal expansion tank, plus it is smaller. https://www.supplyhouse.com/sh/control/search/~SEARCH_STRING=BVECXL

Thanks for letting me what this valve is. But now I’m wondering why do you need a thermal expansion relief valve in addition to the Thermal pressure relief valve?

 

[Reach4]

You don't want regular flow out of the T&PR valve. The T&PR releases water at about 150 psi. So having the 125 psi relief protects the T&P relief valve, so it is more likely to function in an actual WH failure.

 

[Master Plumber Mark]

Yes! Zurn Combination Water Heater Shutoff and Thermal Expansion Relief Valve, at least I think it is Zurn, but could be Apollo.

Does the casting say Zurn? Apollo makes similar. https://www.zurn.com/products/water-control/relief-valves/bvecxl https://www.zurn.com/media-library/web_documents/pdfs/specsheets/bv-bvecxl-pdf

Releases water typically at about 125 psi. Down side is that it uses water, and thus it may not be allowed in some places. Upside is that it may last more decades than a thermal expansion tank, plus it is smaller. https://www.supplyhouse.com/sh/control/search/~SEARCH_STRING=BVECXL

They have a tendency to piss a lot of water down the drain and not stop...

I dont care for them at all

 

[Jeff H Young]

looks like Im probebly incorrect the valve appears to be a relief I can think of a use for it but generaly I would have no use.

 

[Reach4]

looks like Im probebly incorrect the valve appears to be a relief I can think of a use for it but generaly I would have no use.

California inspectors, and those from other water-shortage areas, would be horrified if you used that method.

 

[Jeff H Young]

California inspectors, and those from other water-shortage areas, would be horrified if you used that method.

Im not horrified but puzzled . The W/h has a t and p this extra relief valve was a method to do what?

 

[Reach4]

Im not horrified but puzzled . The W/h has a t and p this extra relief valve was a method to do what?

Keep the T&P from continually opening up, and perhaps locking up in the process. You are not supposed to use the T&P valve as the way to handle thermal expansion.

 

[Jeff H Young]

we use expansion tanks never seen that instead of a tank