Need HELP w/ high water pressure!!

[PATRO]

Quick history, about 2.5yrs ago we noticed that after running hot water for a while (taking showers mainly) the water pressure would be very strong for a few seconds the next time we turned the water on (hot or cold). Got so bad that the water line to fridge blew off several times. Water Co. checked line pressure which was ok. Water heater crapped out couple months later and a new one was installed.

Problem seemed to be fixed until lately. Been noticing the same problem after using a lot of hot water. Tonight the line blew off the fridge again from the building pressure.
I had a POS Whirlpool water heater the first time and had to go with Whirlpool again when it was replaced last summer.

Why is my hot water heater building pressure like this after running for a while or is something else going on?

Please help!!

[RoadrashPaul]

Let me start by saying I am no plumber. What temp is the water heater set on? Is there any water leaking out of your pressure release valve? Might have to install a pressure control valve.

[dward51]

Sounds like a bad pressure relief valve on the heater tank.

As the water heats up, it expands. If there is nowhere for the pressure to release back to "normal" levels if all the faucets are now turned off. It will also put pressure on the cold side of the system through where the water comes into the tank if you don't have a check valve installed.

I would first try pulling the lever on the pressure relief valve up and letting water flush out for about 30 seconds. It may just have some mineral deposits on it. Then see if it keeps doing what you described. If so, replace the valve.

Than again, I'm no plumber either.....

[PATRO]

Thanks David.

I just went out and looked at the heater and it appears that it has had some water come out of the relief valve. This heater is only 1.5yrs old but I will try to flush it some and see what happens. Might take this heater back to Lowe's and get another one if it doesn't get better.

[dward51]

I don't think it is supposed to need to use the pressure relief valve after every use like you described. There may be something else going on in your plumbing system also. I think we have found a symptom but not the root cause.

I know they replaced the meters in our area this summer. The water company sent out letters ahead of time saying the new meters had a new backflow preventor and homeowners may need to install one of those air bladder or thermal expansion tanks in their lines. They said the new backflow preventor may cause pressure buildup like you described if you don't have one of these relief tanks.

You may want to ask the water company if they have changed out their equipment and if this may have something to do with the increased pressure from the heating of the water.

Either way if you don't have one, you want to look into putting one of those tanks in as well. Should be able to find it at home depot or lowes.

Here is the letter the water company sent to us describing the issue. Sounds just like what you are seeing to me.

http://www.hcwsa.com/customerc...r.pdf

Here is a link to a company who makes tanks and has a good illustration of the problem and how the tank solves it.

http://www.watts.com/pages/lea...Id=64

[tmbullet]

I am plumber and sounds like you have your water heater turned up to much you water on the hot side of any water supply should not exceed 119 degrees by code.....

[pete 1]

i had to have a water pressure regulater installed after it busted 2 hotwater heaters. that cured all my water pressure problems. need to check that pressure incoming don't know why mine was so high every one elese was ok here in the subdivision but there was a lot of hot water hearters replace at the 5 year mark.
you need to check that a place to start.

[Jim285pro]

As Bill Dance says, wait a minute wait a minute. First off how much pressure do you have? The water company said ok but how much PSI? You need to check this first. Go to hardware store and buy a guage that screws on a hose bibb. Preferably check the back bibb at your house. It should be on the regulator if you have one. The city main fluctuates on pressure based off usage. Ex. At 2 am no ones using water so the main will have more pressure as will you.

The temperature and pressure valve on your water heater shouldnt discharge unless something is wrong. Read that again, its a safety valve not a normal use valve.

Code isnt 119 degrees but it is law that I as a licensed plumber cannot set it higher than that but you are welcome too but should be advised especially if there is children in the home. Temperatures over 125 can burn in seconds.

Lastly, water expands as its heated, therefore a 50 gallon water heater after heated will expand approx. 2.5 gallons of water(water expands 1/26th its volume). In the past (before 9/11) the gov. was pretty chill about water in a dwelling flowing back. In the past as your water was heated it would push back on the cold side and actually flow back into the cities main. It cant push out of the hot because that side is closed. Now that new meters all prevent backflow you need a thermal expansion tank to give a space for the water to flow back to. Its a steel tank with a rubber bladder inside. Air pressure is on the back side of the bladder. The tank must be precharged approx. 5 psi above your home psi other wise its effectiveness is nullified. recommend calling your local plumber.

Now on the other hand whirlpool heaters are shit so the heater failing could just be a coincidence and the pipe busting could be installed incorrectly. Judging from your symptoms you described I doubt it.

Also your line to the fridge shouldnt be installed on the hot side. Its cold only. Most likely is cold and your having some pressure problems.

[snowblind]

Adding a Thermal Expansion Tank to the water line above your hot water heater more then likely will solve your problem

[MasterCASTER!]

+1 on the expansion tank if you're having the TP valve go off everytime you use hot water.


One question I have though - how in the world is his hot water tank causing his fridge water line to blow? Wouldn't that have something to do with the pressure valve on the main coming into his hous?

We had the opposite when we moved into our house - our water pressure sucked big time. I went into the basement - where the main comes into the house, and there is a valve you screw one way or the other to increase/decrease your pressure throughout your house - this fixed my problem.........

[PATRO]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Jim285pro &raquo;</td></tr><tr><td class="quote">Also your line to the fridge shouldnt be installed on the hot side. Its cold only. Most likely is cold and your having some pressure problems.</td></tr></table>

It is on the cold side.

After hot water is run for a length of time is when pressure builds up on the system. You can turn on hot or cold water and get the burst of pressure but only after hot water has been on, no other time will it do it. My heater was set at 125 and I turned it down a little but it still does it.

Not sure of the water pressure reading but it was in spec. with the water company. The water system my house is on has a reputation for having low pressure.

[Jim285pro]

Do you have a pressure regulator?

Take your hot water temperature to see the exact reading.

I still recommend testing your PSI yourself.

Its the water companies job to get you water not regulate or keep it at whats code for your water system.
Sometimes these things are hard to diagnose without seeing everything but we can solve it if we have all the info.

[Jim285pro]

If you have a history of low water pressure and the water company has tried to resolve it they may have installed a booster pump somewhere in the main thus causing you the fluctuation in pressure after using water for a long period of time. The fact that your saying its hot is coincidence. You will be using both hot and cold in the shower but the showers are the longest period of running water. What you need to try is running cold water only for the time you normally see the problem after a shower and see if it still shows up.

If this is the case you need a pressure regulator followed by a 5 gallon expansion tank installed where the water enters your home. You may have a pressure regulator already but if its 7 years old replace it.

[PATRO]

Thanks for all your help Jim. It's not just my house but everyone on this water system complains of low pressure. There is not a booster pump nor a regulator on my house.

I haven't seen it do this after running a lot of cold water like when I wash the cars or water the lawn, just after hot water use. I wish I could of bought a different brand of hot water heater but my old quit on a Friday evening. Everything that was Whirlpool in my house was junk.

I will try to get a gauge to take a reading.

[Jim285pro]

Let me know. The purpose of the expansion tank at your regulator would be to give you a 5 gallon cushion of water and keep your pressure more consistent. The more inconsistent the pressure the bigger expansion tank you need. It works by the air pressure pushing the water out consistently and the water from the main just refilling the bladder. Worst case would be a 20 gallon tank, which is standard size if your on a well pump system. When a expansion tank fails on a well system the pressure fluctuates like your describing.

As far as a booster pump, it may not be close to your home but its pumped from somewhere regardless if they added it or not.

Question) Is your house on a hill?

[PATRO]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Jim285pro &raquo;</td></tr><tr><td class="quote">Question) Is your house on a hill?

</td></tr></table>

No, it's flat land.

I've had several other people tell me to install an expansion tank. Do you know roughly what the cost would be to install one?

[Jim285pro]

Depends on your current plumbing and how accessible it is. Ballpark figure for the 20 gallon with labor 450-750

[Garfish]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by PATRO &raquo;</td></tr><tr><td class="quote">Thanks for all your help Jim. It's not just my house but everyone on this water system complains of low pressure. There is not a booster pump nor a regulator on my house.

I haven't seen it do this after running a lot of cold water like when I wash the cars or water the lawn, just after hot water use. I wish I could of bought a different brand of hot water heater but my old quit on a Friday evening. Everything that was Whirlpool in my house was junk.

I will try to get a gauge to take a reading.

</td></tr></table>

If you know you don't have a pressure regulator, that's the second thing you should buy and install after you get the test gauge.

[akadewey]

I live in a townhouse community and have this very same problem, after hi hot water usage, there's pressure build up and the T&P valve usually blows. Actually replaced a h2o heater, just because it was 20yrs old and the T&Pvalve seemed to be leaking. I've replaced press reg, had a time of it to get it stop whistling, I believe water co does have some very serious pressure available, due to demand. Could it be I need a press reg. to handle 600psi instead of the standard 400psi? Or should I just get one of these thermal expansion tanks? And I see some conflicting info on these, install in the main line just after press reg or in the hot water line above water heater?

[Jim285pro]

Welcome to BBC. You need a thermal expansion tank. There is several different applications for these so dont let that confuse you. Water expands as its heated so it needs somewhere to go rather than out your T & P valve. depending on the size of your heater you prob need a 2.5 gallon installed on the cold side of your water heater but within 5 feet of it preferably. The tank MUST be precharged 2-5 PSI above your water pressure otherwise its effectiveness is nullified.

Your water pressure in your home shouldnt exceed 75 P.S.I.