pressure relief valve

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  #1  
Old 11-21-02, 08:07 AM
m_spart
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Question problem with pressure relief valve

Hi All!
I have problem with my water heater (gas). We replays some part in the bathroom and I shutdown cold and hot water for the second floor for the some period of time.
Next -day water comes from pressure relief valve. After some time its stops. I decide to flush water heater. I drain some water and now pressure relief valve is leaking consistently.
Itís a problem with the pressure relief valve or maybe my water heater creates more pressure inside and makes water coming out from my relief valve? Where I can check the pressure inside boiler? The only detector I have is in the conner where water comes to the house.

Thanks.
 
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  #2  
Old 11-21-02, 10:53 AM
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Replace the PSV. It's cheap enough, and they do go bad.
 
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Old 11-21-02, 11:41 AM
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m_spart:
You may have a pressure/temperature relief. If the water temp is too high it may be close to the trip point.
Check the water temperature, 140 deg F is usually ok.
 
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Old 11-21-02, 02:02 PM
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Cool pressure relief is a trip...

Trying to diagnose the problem without test instruments is slipshod at best. There are several things that would cause this. The most obvious thing you need to ask yourself is...Is it doing what it was designed to do???
I think it is tripping because the pressure in the hot water heater has nowhere to go. As the water heats up its volume increases. When it hits the relief pressure rating as indicated on the valve, it releases or seeps till the thermostat is satisfied, and then resets unless someone uses water.
Why? you may ask!,,, because the expansion tank is full of water and has no air in it!If its a convensional air tank it needs to be recharge. If its an air bladder type, it needs to be re-inflated OR replaced. Most steel conventional tanks have a gauge glass, the air bladder type, tap with a screw driver on the side and if it is a soild sound top to bottom, full of water, you'll know it.

 
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Old 11-21-02, 06:20 PM
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m_spart:
Did you get a chance to check the water temperature. You can check it at a tap by running hot water over a cooking thermometer.
Also did you drain it at the bottom tap or through the pressure relief?
 
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Old 11-22-02, 06:04 AM
m_spart
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Thanks everybody for help.
I think I have convensional air tank. My system 8 y.o. York. I decrease water temperature yesterday and it's still licking. Also I drain water through pressure relive valve and drain too. Should I just go head and replace valve?
Thanks.
 
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Old 11-22-02, 06:30 AM
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m_spart:
It is possible that there is some dirt under the seat of the relief valve. You can try opening and closing it a couple of times to see if that flushes it out. Make sure you open it fully and let a fair bit of water come out. If this doesn't work you will have to replace the valve.
What is the temperature of the water?
 
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Old 11-22-02, 06:37 AM
m_spart
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I did not check temperature, but on the boiler it's stay little ower "warm". I usually keep it "hot". And I open and close valve for a couple times - not help. The only thing that worry me , if I replace valve and it's not help. So next step will be to replace whole things (boiler)?
 
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Old 11-22-02, 06:52 AM
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m_spart:
It may not seem important to you, but you have to help us help you.
Again I'll ask you to check the temperature of the water. You can get a digital cooking thermometer for about ten bucks that will do the job.
But maybe it would be easier for you to have someone replace the boiler.
 
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Old 11-23-02, 11:03 AM
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Hold on...

Theres nothing wrong with the boiler. Lets first see whats going on. Is this a tankless water heater. In other words, does the hot water get heated through the boiler, go through a mixing valve and then to your hot water outlet?( No 40 gallon storage tank and circulator) If you run the hot water only, can you keep your hand in the water withour getting scalded? If not , it's too hot.
Does your conventional compression tank have a gauge glass, if so can you clearly see a water level in it? Look at the boiler gauge. It shows temp and pressure. While its leaking, what are the readings indicating?
 
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Old 11-23-02, 11:15 AM
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A check tool

A good check for the pressure, Go to home Depot and get a pressure gauge for 0-150 PSI and an adapter for a hose connection. screw this onto your drain connection and open the valve. Does the reading exceed the pressure relief? If not, the pressure relief is defective, If it is too high, lower the pressure reglating valve (PRV) outlet setting, or replace the PRV..this should be way below the tank setting. The pressure relief releases for two conditions, too hot or too high pressure.Have some patience...
 
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Old 11-25-02, 06:37 AM
m_spart
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I will measure pressure inside boiler and water temperature today (need to buy equipment in Home Deport) and I'll post it tonight.
I donít have gauge glass on my tank. If water temperature is too hot Ė this is why valve may leak?
In mean time, I replace pressure relive valve yesterday and it's still leaking.
Thanks everybody for help.

Greg.
 
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Old 11-25-02, 10:20 AM
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Question off hand.....

What was the pressure rating of the relief?
 
  #14  
Old 11-27-02, 06:14 AM
m_spart
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Water pressure was to high 80 pa. I make it around 25 and sound like it's stop leaking.
Thanks everybody for help.
 
  #15  
Old 11-27-02, 08:17 AM
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Hold on....

Is this pressure relief on the Boiler or a holding tank for hot water?
Also you still didn't say what the rating was for the pressure relief valve. Its stated on the tag of the valve. For a hot water storage tank...the pressure rating is most likely 150 PSI. For the boiler its only 30 PSI. and the PRV should be set to 12PSI for a 2 level house and 18PSI for a three level house. Your not done yet if this is the boiler cause there are certain steps that must be taken to set the pressure correctly.
Lets first find out about the relief. Do you know what a tankless water heater is? Also if you have the old relief did it have a tag, what did it say? It should have a BTU rating and setting.
RSVP
 
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