I’ve got a 1 1/2 year old Sears gas water heater that is leaking from the pressure relief valve down tube. It appears to leak its worst when the tank is heating the water. I’ve replaced the pressure relief valve twice. (thinking the first one might have been defective) It’s leaking about 1 gallon/day.
The manual says it might be due to water pressure fluctuations, but if that was the case, wouldn’t it be leaking all the time, and not just when it is heating water?
If it’s due to pressure changes, is there some kind of valve I can put on to moderate the changes? Does it go on the water supply line for the water heater, or on the main line? By the way, I’m on rural water.
Thanks in advance.
Tracy
Replies
Sounds like you need an expansion tank.
Man,
How hot is your water set at? It is really a tempature/pressure relief valve. If the tempature is set above 135 or so combined with higher than average pressure it will cause the valve to fail early. Hot water is not supposed to be set above 125 degrees to avoid scaulding. DanT
DanT,
I believe you have your temperatures wrong, but you're heading in the right direction. A working T&P valve would drip if the temp's too high, so I wouldn't necessarily believe that two in a row were faulty. Anyone check the water temp at a tap?
I don't think I have a thermostat that will read high enough to take the tap temperature. I have it set on "A", which is higher than the normal indicator arrow, but lower than "B" and "C" and "Very Hot." The pressure relief valve gives its rating for temp and pressure, but it seems like I remember it being higher than 120 degrees. I bought it at a real plumbing supply store, so it's not junk.
Sounds like you're town might have very high line presssure -call your water dept.
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I'd start of by replacing the popoff valve. It's the cheapest and easiest fix. And it might be the problem. Could be defective or have some rust stuck in it.
If that's not it, I suspect you have a backlfow preventer in your water line, and need an expansion tank as WIVELL suggested.
The high water pressure idea is also possible. (Got any way to check the pressure?) But if you're on a rural water system I kinda doubt it. Around here rural water means LOW pressure.Let him who is without aim cast the first stone.
Thanks guys. We used to be on a private well, with a pressure tank. Due to water quality in our area, a small town ran rural water in the area and we had the option of hooking on to their supply. I now have a meter with the main supply line through my yard to just outside of the well house and they tied into the house supply line there. I'm sure I have a back flow preventer somewhere on the line. I thought this change of water supply might be the problem, but it didn't start leaking just as soon as we hooked up to the rural water. It was after by about 6 months.
If the solution is a pressure/expansion tank, where would it go? Next to the water heater in the garage? ( I don't really care for having the hot water heater in the garage, but it's been kind of handy since it's been leaking) I for sure don't think I have room for it in the garage. Can I tie into the supply line just past where my rural water meets my house supply line, then run a new line back to my old pressure tank in the well house?
Thanks for all of your help thus far.
Tracy
Yes the expansion tank can be any place in the system as long as there is no check valve between it and the hot water tank.
But you really don't need a tank that big, most of them are very small.
Here is a link that describes the problem.
http://www.wattsreg.com/default.htm?/thermalexpansion/
And here are some tanks, the 2 gallon size would work for you.
http://www.wattsreg.com/default.htm?/es/pet.htm
And here is one built into some "fat pipe"
http://www.wattsreg.com/default.htm?/es/ilt.htm
And here is an alternte options. It bleeds the excess pressure off into the toliet tank.
http://www.wattsreg.com/default.htm?/es/gov80.htm
All standard disclaimers.
Given that situation, I'd say the pressure tank is likely your answer. Especially if the problem happened when you hooked onto the new water system and it has the back flow preventer.
The expansion tanks I've seen have been mounted directly above the water heater. There can't be any valves between the water heater and the expansion tank, I believe. Maybe one of the plumbers will jump in here with some more specifics. And be sure to check your local codes if you have any.
Please let us know how it turns out.I doubt, therefore I might be.
I'd recommend a small bladder tank, like the kind used for well systems. A bladder tank won't waterlog like an expansion tank would. The smallest tank you can find is good.
If your water lines are copper, be sure to use a dielectric union between the steel fittings on the tank and your copper lines, to minimize rusting of the steel.
It can be installed anywhere in the cold water system of the house, so long as there is no check valve between it and the water heater. I would not put it in the garage, in fact, I would never put any water piping in a garage because it could freeze. Even putting water lines within the outside wall of a house is a bad idea.
" But if you're on a rural water system I kinda doubt it. Around here rural water means LOW pressure."
Not nessecarrily. One of the districts that I have done work for the max pressure readings where near 1000 psi and they had to use stainless steel piping.
Now it went through a couple of stages of pressure reducers before it got to the customer unless they where on the other side of the mountain where it would be low again.
Almost all water deliver is gravity feed. If you are at a high spot you have low pressure, if you are at a low spot high pressure.
The exceptions to gravity feed skyscrapers (that does not include the 1 3 story building in your town <G>) which has to have booster pumps and some of the extreme cold places. In those they use varriable speed pumps and multiple pumps that are staged. In one control scheme the flow rate and pressure is monitored at the high service pumps and using system curves as the flow increase the pressure is increased so that the pressure at the far end of the system will remain within specs.
Edited 2/17/2004 11:28:02 AM ET by Bill Hartmann
"Almost all water deliver is gravity feed. If you are at a high spot you have high pressure, if you are at a low spot low pressure."
You got that backwards...
High spot=low pressure
Low spot=high pressure
Never heard of a 1,000 PSI system. Must be one heck of a pump, or a whoppin' heck of a long vertical drop.If you don’t think every day is a good day, just try missing one.
Thanks guys. I'm going to call the city water district first to see if there's anything they can do for me and the next call will be to my plumber.
Thanks, I went back and edited. That is what get for trying to do 2 things at once, typing and thinking <G>.
Yes, that was a big downhigh run. Lookout Point, TN.
Worked in a plant where the water pressure was 2250 psi. Course, it was radioactive...
The pumps Bill refers to would have to be multistage centrifugal to achieve that kind of pressure without a high suction head. (Positive displacement pumps - gear or piston type- will pump as high as you want, until something breaks, like a pipe or casing, but they aren't good for high volume, unless you have a number of them in parallel.)
Worked with some humongous pumps in my day, pumps that were over 3 storys tall, used 6.9 kv, and rated at 12,000 hp. Talk about NOISY. What? I can't hear a thing!
I never met a tool I didn't like!
If your water is trapped in the heater and piping, and you heat it, the expansion of the water will build pressure and pop the valve. The water can't go out the hot water outlet because all the hot water faucets are shut. Normally the pressure relieves back out the inlet into the water supply. But, if you are on a well there is a check valve in the well or at the pump so the water can't go back there. The only other place it can go is into the pressure tank that stores the water from your well.
I think you either don't have a pressure tank, or if you do and it is the old fashioned air kind, it's waterlogged, or if it's a bladder tank the bladder is broken or there is no air charge.
When you say "rural water" if you mean piped water from a municipal source, you should not have a check valve installed which would prevent water from flowing back to the supply.
"When you say "rural water" if you mean piped water from a municipal source, you should not have a check valve installed which would prevent water from flowing back to the supply."
A lot of cities are installing check valves or backflow preventers.
I had the same problem in two different homes. The first time water was discovered on the floor, the dogs were thought to be the the source of the problem. Once they were eliminated as the culprits, an expansion tank for potable water solved the problem 100%
good luck
I will bet that you have a check valve between your water heater and your street supply. That being the case, when the water is heated and expands, it has no place to go. Consequently, the pressure is increased and the T&P valve releases. You clearly need to install and expansion tank so you are not submitting your entire plumbing system to such high pressure cycles.
All this talk of elevations and water pressure made me think of The Old Mill at my Alma Mater, Berry College, in north Georgia. It's one of the largest overshot water wheels in the world, on what is reputed to be the largest college campus in the world, about 28,000 acres. An absolute paradise.
http://www.berry.edu/oakhill/oldmill.asp
The Old Mill is at the lower elevation of Lavendar Mountain and the school's reservoir is on top of the mountain. Maybe a 60 acre lake. There's a closed pipe that brings water down the mountain, several hundred feet of drop in elevation. When you first see the mill, you find yourself looking for a flume to bring the water to it for the overshot, but it's simply a stone tower with the closed pipe inside. The water rushes up the pipe and over the wheel in great volume and with great force.
If you're ever in Northwest Georgia, near Rome, Georgia - don't miss it.
Greg
Edited 2/17/2004 4:11:12 PM ET by Greg Gibson
Edited 2/17/2004 4:12:00 PM ET by Greg Gibson