Pressure valve flooding house

[Runs with bison]

This is an Aprilaire 360 Humidifier and it uses water mixed through a regulator, to come out no more than 140 degrees. Good unit. Saves hauling water to tabletop units every day and the cleaning mess.

Okay, I see now. This is not connected to a furnace and uses hot water as the heat source. So you can't go with cold water for the the feed.

Link I found online says it uses up to 6 gallons of water/hour so I could see it causing a lot of short cycles.

The online version of the manual says that the feed water should be 140 F maximum. It doesn't say anything about mixing it with cold water.

[MACPLUMB 777]

Just to correct one point, the T&P valve will open at 210 degrees
212 degrees is the boiling point of water at sea level, these type of safety devices are to open at least 2 degrees
below that point, but with your house water pressure at 60 to 90 psi the boiling pressure is much higher then that
If the water temperature ever got that high over 210 degrees when you open a faucet and the pressure drops
the super heated water at the top of tank will instantly flash to steam and 2 micro seconds later you have
Space Shuttle CHALLENGER and then your house follows into the street

PS a note water heater and boiler safety devices are all designed to work or fail at the lowest set point to save
lives and or property

[jadnashua]

Normally, a WH has a decent convection current that keeps all of the water in the tank relatively consistent with no use. But, if you get certain special conditions, it might stratify. This effect is often used with salt water and fresh water to produce very hot water in one layer to store energy.

Just like your car's radiator doesn't boil at maybe as much as 240-250-degrees because it is under pressure, the water in the WH won't, at least until it is released to a low enough pressure. If it ever did get that hot (it shouldn't if the safety valve is working and the discharge pipe is not blocked), it would be very dangerous to both life, limb, and property.

[Runs with bison]

but with your house water pressure at 60 to 90 psi the boiling pressure is much higher then that
If the water temperature ever got that high over 210 degrees when you open a faucet and the pressure drops
the super heated water at the top of tank will instantly flash to steam and 2 micro seconds later you have
Space Shuttle CHALLENGER and then your house follows into the street.

Well, not quite...when you open the valve the pressure in the tank would still be about the same, but it would begin flashing in the line on the way to the fixture as the pressure dropped through the line. You would get water first until the hot water reached the faucet, then it would start sputtering water and steam and then blow wet steam pretty hard. At 90 psig the saturated water temp would be close to 330 F. That would provide enough enthalpy to boil something like 10-15% of the water coming out of the tap. Volume wise that is tremendous so it would be a noisy nasty jet of steam and boiling water! But the tank itself would still be liquid full or nearly so other than some steam bubbles forming at the hot water tap.

Fixtures are restrictive enough that most of the pressure drop is taken there. There would be an hellacious amount of energy in that tank though, so that if it ruptured a large volume of steam would flash off and cook anyone in its path. If my back of the envelope numbers are correct a 50 gallon tank of saturated water at 90 psig would liberate something over 1500 cu. ft. of steam at Denver's altitude.

[master plumber mark]

none of these other astute fellows has asked how old the heater was ,
or how long ago it was installed.....or who installed it for you
or how much damage was done to your home.....??

if you have high water pressure you probably should have
a thermal expansion tank at the very least on your heater
and you should change out the T+p valve....

if you have a FLOOR DRAIN the pressure relief valve pipe
should be piped and inserted directly into the drain... as long
as it does not stop up , it will prevent flooding in the future..
or pipe it to the laundry drain

I just left a job that sears did with no pan, no drain, no nothing
with the t+p pipe just going down to the slab floor....

if something has just recently been installed like this and it was
done by a plumber, and they did not offer you these options,
their insurance company should be on the hook for the damages....


if you had a hack from Sears or Lowes
install the heater recently, then its on you..

[Hackney plumbing]

none of these other astute fellows has asked how old the heater was ,
or how long ago it was installed.....or who installed it for you
or how much damage was done to your home.....??

if you have high water pressure you probably should have
a thermal expansion tank at the very least on your heater
and you should change out the T+p valve....

if you have a FLOOR DRAIN the pressure relief valve pipe
should be piped and inserted directly into the drain... as long
as it does not stop up , it will prevent flooding in the future..
or pipe it to the laundry drain

I just left a job that sears did with no pan, no drain, no nothing
with the t+p pipe just going down to the slab floor....

if something has just recently been installed like this and it was
done by a plumber, and they did not offer you these options,
their insurance company should be on the hook for the damages....


if you had a hack from Sears or Lowes
install the heater recently, then its on you..

I personally would never insert a relief line INTO a floor drain. The floor drain could back up and clogg the relief pipe. Not likely to clogg it but possible depending on what backed up from the drain.

If a hack from sears or lowes installed the heater she would be golden as far as liability coverage......wouldn't you think MASTER Mark? Those guys are licensed and bonded,they are just plumbers subcontracting through the store.

[master plumber mark]

I personally would never insert a relief line INTO a floor drain. The floor drain could back up and clogg the relief pipe. Not likely to clogg it but possible depending on what backed up from the drain.

If a hack from sears or lowes installed the heater she would be golden as far as liability coverage......wouldn't you think MASTER Mark? Those guys are licensed and bonded,they are just plumbers subcontracting through the store.

anything you can do to keep a flood from happenning is very wise.....

if you can insert the t+p down slightly into a floor drain,
I would suggest you do it.. I am not talking about cramming it down into
the bottom of the trap here....

the odds of a floor drain backing up and stopping up the t+p pipe is
close to impossible, or you can always give it an air gap of an inch above
the drain ....... whatever you feel is best....

this is a common practice and it should be done over just putting the t+p
into the water heater pan and pipeing it over to a drain... the pan can be
over-whelmed by the sheer volume from the t+p ...
I know this from one I was involved in just last week
My own personal experience with a flooded pan


I dont know when or whom did the work, or how long ago it was done either
so everyone will be heading for the hills looking for a rock to hide under if
she trys to turn it into her insurance.....that you can depend on....

here is one we tore out from Sears just on tuesday...this unit is about two weeks old...basically brand new..

there is no pan, no floor drain, no thermal expansion tank, the shut off valve cannot be gotten to behind the heater... this Sears unit also had the crapppy honeywell valve on it.

this was installed by a SEARS sub-contractor....
so would Sears have to pay the bill if the t+p valve
flooded this home ??? yes or no??

do you think would it have been wiser to pipe the t+p
over to the laundry drain about 5 feet over ?????

so what would you do to think
would make this a better install.????.

click to enlarge.
.. aint this something to be proud of??

[jadnashua]

From what I hear, the rules on terminating the T&P valve's outlet have changed in the recent code books, so check carefully when installing a new WH. I gather from comments here that people don't think much of the Taco WAGS valve, but personally, I think it is a good idea - if water builds up to about 1/2" in the drain pan, it shuts both the WH and the water supply off...unless the tank has a catastrophic split, no floods. It's totally mechanical, no power (except the built-in switch to control the WH firing), and uses the same tech as the autoinflaters on a lifevest used in airplanes - a disk disolves when wet and a SS spring closes the water valve.

[master plumber mark]

From what I hear, the rules on terminating the T&P valve's outlet have changed in the recent code books, so check carefully when installing a new WH. I gather from comments here that people don't think much of the Taco WAGS valve, but personally, I think it is a good idea - if water builds up to about 1/2" in the drain pan, it shuts both the WH and the water supply off...unless the tank has a catastrophic split, no floods. It's totally mechanical, no power (except the built-in switch to control the WH firing), and uses the same tech as the autoinflaters on a lifevest used in airplanes - a disk disolves when wet and a SS spring closes the water valve.

the Wags is a one shot wonder,
once it gets wet, its over and you have to intsall a new one
I dont even know what they are worth, but they are not too popular

the t+p valve could barely weep a small stream and
trip this mechanism to go off.....

as far as the code goes, pipeing the t+p to the floor drain
is ok as long as their is an air gap...or it is laying on top the drain..

at least a dozen times we have gone out to homes where the water
heater was on the second floor and the t+p pipe was hanging in
mid air 5 inches above a 3 inch pvc cup that was used as a floor drain.
Normally, they are sunk and flush at the floor level so the pan could go into it also...
..
the t+p blew and half the water hit the drain
and the other half sprayed everywhere and flooded the home.
I feel its best to err on the side of caution and have that pipe
inserted into the drain and zipped tied off so it cant move.

I do whatever I think is best for the situation
that is presented to me to protect the property
from serious damage.
..

[jadnashua]

It takes about 1/2" of standing water to trigger a WAGS, but as far as I know, yes, once triggered, it must be replaced. In theory, it could be reset, but I've not looked into it. A little weeping into a pan should not be enough to trigger it unless the drain is plugged and it accumulates. What's worse, replacing it or maybe thousands of dollars of damage if it leaks all over. Plus, if the tank leaks faster than the fill, the burner could create other problems...but, if it is disabled, all's better. Think of it as an insurance policy.

[Hackney plumbing]

I use 1.5" sch 40 pvc for my pan drains with a combination wye&1/8 bend near the outlet of the pan with a 2' stub of pipe vertical. I pipe the relief line indirect no more than 6" into this vertical riser off the pan drain.

The thermocouple adapter that the wags valve uses is useful for trouble shooting water heaters under load.

[ST1300Rider]

I am very sorry to hear of your flood.

I had one w/a washer that kept filling.

The thing going forward is how to prevent these super unknowns.

I use FloodStop valves(electric ball solenoid) on all my critical interior needs(fridge; eBidet and whole whouse water filter in my closet) and I don't worry about those...

FWIW...here is the link.


http://www.safehomeproducts.com/shp2...9&menupage=975


It uses a sensor plate and when a drop of H20 hits it...it closes the water supply to "x"...ending the flood.

Hope it helps and again; sorry to hear about your dilemma.

[master plumber mark]

those look pretty nice.... for 150 bucks that is not too bad
just put the sensor plate down in the bottom of the pan.
and it has an alarm and shut off...

this is much, much better than a wags valve...

[jadnashua]

this is much, much better than a wags valve...

And what happens if this occurs while the power is off? Nothing...the water still flows. WAGS, it stops. Do you have any personal experience with a WAGS valve that jaded your thought? I've not used either, so am only looking at the 'features'. I'd really like to know.

[Hackney plumbing]

And what happens if this occurs while the power is off? Nothing...the water still flows. WAGS, it stops. Do you have any personal experience with a WAGS valve that jaded your thought? I've not used either, so am only looking at the 'features'. I'd really like to know.

I agree the wags valve is the most reliable way to stop the water flowing to a water heater incase of a leak.