Water heater expansion tank busted

[nisryus]

So this morning the expansion tank for the water heater ruptured and gushing water all over the garage.

What is weird is that the expansion tank is not directly attached to a pipe that leads into the water heater, but is to a pipe from the wall.

I shut off the main water valve, got up and shut off the cold water into the water heater, and turn the heating dial to pilot.

Already unscrewed the expansion tank. But since we have a snow storm here in Texas, road condition is terrible and dangerous. I checked HomeDepot and Lowes, none have it in stock. Ace Hardware also doesn't has it. Other plumbing supply stores not picking up their phones. Called several plumbers and no one answered or ave voic email saying business closed for the day due to weather.

Is it ok to just cap it and get a replacement later?

Is it better to hook up a hose (will need to check if a hose will fit) and run it outside, and turn on the main water?

 

[herm0016]

looks like it may have froze. it may have not been working properly also, because the water should have been contained in a rubber bladder inside the metal tank. even if it froze it would expand the bladder and not blow up the tank. you will be fine capping it and replacing when you get a chance.

 

[nisryus]

Thanks herm.

Problem is due to icy road, everywhere is close and not safe to drive. So can't go to home depot or any hardware store to get a cap. Forecast another snow storm tomorrow.

Wife is in an extremly foul mood.

 

[Torn Mind]

Interesting feature. Never seen it before where I am. Reading up on it, this seems like an insurance device so the water heater itself doesn't go boom.

Temporarily, you probably can just by with capping it off. Maybe reduce water temps if you are the wary type.


I have experience with one house with well water. Pressure tanks operate similarly to this kind of tank.

Pipes of CPVC had exploded due to 2 or 3 years of neglect and cold temps BUT the crappy Flotec pressure tank only had the rubber bag fail at the time, no explosion. Of course, that meant rusty brown water inside of it.

Tried the time-consuming task of putting the bag back in only to have a leak and the bolts fail due to the rust damage.

 

[herm0016]

the expansion tanks on HW I think are code now, but I have never had one in a house i have lived in. perfectly fine to cap and deal with it later.

 

[MtnMan]

the expansion tanks on HW I think are code now, but I have never had one in a house i have lived in. perfectly fine to cap and deal with it later.

My house was build in 1965, and I still have the original electric water heater. The pressure relief valve kept going off and dripping, so got a plumber in. He couldn't believe it was the original water heater, but the manufactures plate says it was made in 1965. He added an expansion tank, now code, which it never had, replaced the relief valve, and took a picture of the plate to show back at the shop. His comment was "they don't make like this any more".

It is a Rheem 40 gal heater.

One of the challenges we have here is the water pressure provided by the city water system. Pressure at the meter varies between 250 PSI and 360 PSI depending on the time of day. Have two Pressure reducing valves in a box at the meter, and another one in the house. When water is heated it expands, and can't push back against the incoming pressure, thus the expansion tank.

 

[lxskllr]

That's impressive. My tank failed a couple years ago, and it was last inspected in 1977. It was older than that, but probably installed in ~1975. I thought that was exceptionally old, but you blew that away. No tank on the original of course, but the new tank got one.

 

[Micrornd]

Pressure at the meter varies between 250 PSI and 360 PSI depending on the time of day.

I'm sorry, but that can't be right. Municipal piping is not rated for those type of pressures and neither are the water meters.
Where are you located and what type of piping is being used for those pressures?

 

[nisryus]

I finally located a plumbing store that has it in stock. Got it replaced over the weekend. All is good.

 

[MtnMan]

I'm sorry, but that can't be right. Municipal piping is not rated for those type of pressures and neither are the water meters.
Where are you located and what type of piping is being used for those pressures?

In the mountains that life. Water meter is just fine with that, water heaters not so much. The pressure relief valve on them is 150 PSI. This is not my "guess", plumbers and the city have checked it with pressure gauges. Watched a plumber connect his 0 - 300 gauge and it pegged it. That's when he asked me to have the city water dept check it, and their report showed 360 PSI at its max. 100' of elevation adds 43 PSI.

When the original iron pipe from meter to the house failed, it was replaced with PVC. That lasted about 3 years, and the next plumber said the problem was with the pressure and it requires schedule 80 PVC pipe.

So yea, it is right, and it is a PIA and a pain in the wallet.