Originally Posted By: rray
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Shutoff valve on the hot water line on a gas-fired tankless water heater.
Yea or nay?
Shutoff valve on the hot water line on a gas-fired tankless water heater.
Yea or nay?
Originally Posted By: rmoore
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I can’t see why it should be any different so my guess would be the same as a regular heater. That is…not needed but no harm if one is present.
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Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com
Originally Posted By: rray
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No harm if one is present on a regular heater? A big no-no if one is present on the hot water line of a regular tank water heater. Imagine the hot water valve being shut off, thermostat goes crazy, and TPR fails to work when the temperature gets too high or the pressure gets too high. Result? Boom! Just like the old steam engines.
Originally Posted By: afernbaugh
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Russel,
Although I don’t remember seeing an isolation valve down stream of a water heater, I don’t understand why it wouldn’t be allowed for the occasional service use. The hot water valves at the faucets are closed most of the time anyway during normal homeowner use. If the thermostat and TPR fail simultaneously it is going to explode with or without an isolation valve.
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Alan Fernbaugh
Five Star Inspection Services
Baton Rouge, La.
Originally Posted By: Guest
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Ray,
No harm in the hot side having a valve, it's no different than turning off the kitchen sink.
Originally Posted By: rray
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This is interesting.
I've only found a valve on the hot pipe a couple of times. Both times I've called it out, and both times the plumber agreed.
We did not allow it in Kingsville, Bryan/College Station, or Houston, Texas, when I lived in those places, and we don't allow it here in San Diego.
Even though only 50 water heaters explode each year in America, safety is still safety, I think.
I'll reserve judgment until we get some more answers in. I can be convinced to change my mind, but it's going to take a lot to do that here, I think.
Originally Posted By: rmoore
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| Chad Fabry wrote: |
| Ray,
No harm in the hot side having a valve, it's no different than turning off the kitchen sink. |
My thoughts exactly. I don't see why it would be a safety issue.
--
Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com
Originally Posted By: jpeck
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I also do not follow where it is, or can be (short of the fact that ‘anything’ CAN BE) a problem or safety concern.
The T&P safety relief valve IS the failsafe safety device.
There is also a bi-metal button at the thermostat for electric water heaters which is a primary safety device which shuts off power to the heating elements. The T&P is the back up in case this fails to operate.
Take this installation: Water heater is in the master closet. This water heater feeds the master bathroom only. There is little (did not want to say 'no', because anything 'can' help) if any thermal expansion absorbing ability of an extra 10 feet of hot water pipe over placing a shut off valve right at the water heater.
Again, if you want to start on saying 'but what it' the T&P fails, then NOT having a shut off valve at the water heater is not what you want, you want a secondary back-up T&P relief valve, and then another back-up T&P in case that one fails, and better install another one in case that one fails, then, in case THAT one fails ...
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Jerry Peck
South Florida
Originally Posted By: rmoore
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| rray wrote: |
|
We did not allow it in Kingsville, Bryan/College Station, or Houston, Texas, when I lived in those places, and we don't allow it here in San Diego. |
Russel...
I'd be interested in seeing the "code" that doesn't allow it. Are you sure that it's not just... no shut-off between the water heater and a remote pressure only relief valve such as you might find on a watts-valve equipped heater (or possibly a tankless heater with a thermal cut-out)? That would, of course, be a problem everywhere.
Once you're "downstream" of the safety devices...well...shut-offs, isolation valves, faucets, dishwasher solenoids, etc...all much the same.
--
Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com
Originally Posted By: wrobedeau
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Check the manufacturers recommendations. Some show valves on both pipes. Here is a site to try.
http://www.tanklesswater.com/
Bill Robedeau