A client wants me to install a 40 gal Bradford White water heater with the above mentioned valve. I had recommended an A. O. Smith but these people are highly educated and research everything on the web. They decided that the Bradford White is superior and found the shutoff valve on the web also. I've not installed one before. I've not even heard of a water heater exploding though I gather it does happen if the thermostat and regular ol' pressure/temp release valve go bad at the same time.

The Watts valve looks like it about doubles the installation complexity (hoop jumping with the gas line and a normal pressure/temp relief valve needs to be installed in a T fitting on the hot water exit port on top) but it does add a third layer of protection. However, I found these remarks from a plumber on the Rigid site regarding the Watts valve:

let me know when you need some. i have a whole case of them and they're not legal anymore in l.a. (frowny face)

and, when asked why:

water getting into gas lines (eek!)

Anybody know about this?

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Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

I could win the NY State lottery tomorrow, as well.

The odds are about the same.

Overkill.

Charge the fools a fortune if you're going to bother with it.

Isnt there a redundant electrical safety on the honeywell gas valve that already comes with the water heater? If you havent seen the options already have a look at all the stuff those new gas valves can do. Programamble thermostat. Automatic water shut off in the event of a leak. Pretty cool stuff.

Not sure. There's a lot I don't know I hate to admit. I like these people, they give me a lot of work and feed me half the time (IT profs, work at home half the time), and it's good food to boot, so I'm not sure how I'm going to tell them that their idea on this is whacked. Maybe I should just do it and charge them more steeply. I don't want to tempt fate but I have NEVER heard of a water heater blowing up. There are a lot of them in the world, you'd think you'd hear about it now and then if it was a problem.

This site has some good diagrams about attaching the Watts valve:

http://media.wattswater.com/es-210-5.pdf

Can't figure out how to lift them off the site and post them direct here - pdf file and all. They have the T&P in a T fitting on top of the hot (or cold) port on top. I have to wonder if the little probe thingy might cut down on flow a bit. Will definitely cut down on the square inches in the opening.

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Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

My advice would be to utilize the direct side tapping as shown in figure 1. If you don't have a 3/4" extra port on the side, I definitely wouldn't bother with the unit. Installing it in a T at the outlet will not allow a trip on safety unless you have water flow at the time of the event. It's a completely worthless installation.

When I bought one of my properties it had an old hot water heater with no TP valve and no port to install one. The water heater sat about 5 ft from the kitchen sink. Being moderately safety conscious I thought it prudent to have a TP valve. I T'd into the outlet at the top and install a TP valve. Worked fine that way until the heater finally started leaking about 40 yrs after its installation.

If they're good customers I'd do exactly what they wanted unless they're asking for something dangerous. Wouldn't you want the same?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Actually, we'll never know if it would have worked fine in such an installation because it never tripped.

I agree. Just charge them for the privilege of being stupid.

I meant work fine in terms of water flow since that is what he was concerned about. I assumed the pressure in the tank would transfer to the lines immediately adjacent to the tank. No?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I thought the device measured temperature............and the temperature at the outlet would be lower than the tank temperature at any given point in time unless water was flowing from the tank.

Hmmm? Not pressure?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

They specify using the side port normally used for the standard T&P valve instead for the Watts thingy. I agree with you on this but I think you're wrong on the T fitting on top not allowing a trip unless the hot water is on. There will always be pressure in the hot water exit port - the tee fitting allows the standard T&P fitting to dangle it's probe into the top of the tank and it has a normal overflow pipe leading downwards.

That doesn't mean I like this thing - the probe will always be in the way of water outflow (or inflow if placed on the cold side) and hot water is usually slightly lower pressure than cold water (at the sink) so this is likely to exacerbate that difference.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

That is more or less my thinking, my difficulty stems from the possibility that this thing could be more of a problem than a benefit. If the Watts valve blows up, you get 60 psi (or whatever) water in the gas line and as gas is considerably less pressure than that, you could have a really lousy problem on your hands. These guys at the Rigid forum alluded to that:

https://www.ridgidforum.com/forum/t37337/

However, I can find no other mention of water leaking into the valve anywhere else, and the second plumber's assertion that they are banned in LA owing to said leakage likewise. You'd think if they'd been banned in LA, no small burg, that there'd be more news about it.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

They only blew up back in the day when they where still hooked up to galvanized plumbing. The strength of the pipe, coupled with no pressure relief valve, and a failing valve in the open position, caused them to blow.

And that was a long shot....

Even with NO pressure relief valve, the copper would burst before the tank would rupture. If the house has PVC, pex, or any other plastic, The risk would be none.

__________________
Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

That's good to know, there is copper in this house, some galvy still as well (older house). I just did a search and numerous reports of water heaters actually blowing up and doing much damage are out there. No mention of copper or otherwise. Mythbusters rigged one for worst case scenario and the explosion was spectacular:

MythBusters - Exploding Water Heater - YouTube

But there was only galvy pipes hooked to it, the T&P was disabled, of course.

It's a tough one, if this becomes more common, tanks are going to need two pressure relief ports threaded in.

Not to be an ass, but if the copper ruptured somewhere, you'd have no house blowing up but you would have hot water (really hot) gushing full bore through some sheetrock somewhere, that is if it didn't rupture right in the utility room.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

Holy crap. My decision to put a TP valve in seems wise.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13