Replacing Furnace Press relief valve (Help!)
 

About a week to go before my house is closing and my pressure relief
value went. I got a replacement value at Home Depot. I turned off the
water supply that seems to come in to the furnace near the value. I
started taking the old value off to replace it and I think the valve is
under pressure still (I guess from the gas furnace itself) since once I
almost all the way off water started coming out of the joint near the
value. Can some one lead me through what else I have to shut off to
replace the value? Thanks!

Jim,
Thanks. It's gas hot water. I am probably in over my head. What do you
think a reasonable price to pay someone to replace the value is?
Thanks.

"Speedy Jim" wrote in message
...
wrote:
About a week to go before my house is closing and my pressure relief
value went. I got a replacement value at Home Depot. I turned off the
water supply that seems to come in to the furnace near the value. I
started taking the old value off to replace it and I think the valve is
under pressure still (I guess from the gas furnace itself) since once I
almost all the way off water started coming out of the joint near the
value. Can some one lead me through what else I have to shut off to
replace the value? Thanks!


If this is a hot water (Hydronic) system, you'll probably
have to drain the entire system.

Good luck. I think you're biting off a lot.

Jim

Jim,
I also have a problem with my ho****er system. I went down to my basement
and water was spewing out of the bottom of my pressure reducing valve. I
notice that there seems to be a plug which is missing. Are these parts
readily available or do I need to replace the whole unit.I am not sure of
the model of the valve. Looks like 2 valves in tandem right after the water
inlet.

Mike wrote:

Jim,
I also have a problem with my ho****er system. I went down to my basement
and water was spewing out of the bottom of my pressure reducing valve. I
notice that there seems to be a plug which is missing. Are these parts
readily available or do I need to replace the whole unit.I am not sure of
the model of the valve. Looks like 2 valves in tandem right after the water
inlet.



That's a dual control. First, a pressure reducing valve
which is set to maintain a specific "height" of water
in the system.

Second is a pressure relief valve which opens when system
pressure exceeds (usually) 30 psi.

The relief valve has a discharge port and that may be where
water is escaping (as it should).

Typical style:
http://www.cashacme.com/genheating.html

See what the boiler pressure gauge reads. Normal is 12-15psi
(depending on building height, of course). If way over that,
the valve may be relieving for good reason. If normal range,
the relief valve may be defective.

Jim

wrote in message
oups.com...
About a week to go before my house is closing and my pressure relief
value went. I got a replacement value at Home Depot. I turned off the
water supply that seems to come in to the furnace near the value. I
started taking the old value off to replace it and I think the valve is
under pressure still (I guess from the gas furnace itself) since once I
almost all the way off water started coming out of the joint near the
value. Can some one lead me through what else I have to shut off to
replace the value? Thanks!


Furnaces heat air, boilers heat water.

Do you have a separate heater for hot water or is it integrated into one
unit? If the heater does both, there are two valves, one feeding the hot
water, the other feeding the heater portion. Close that valve. There will
be some internal pressure that has to be relieved. Put a bucket under the
pressure relief and pull up the handle. That takes care of most. When the
valve is removed, gravity will still allow some water to flow out.

Not seeing exactly what you have, you probably need some Teflon pipe tape
for the threads, a pipe wrench and a large adjustable wrench to open the
coupling. Undo the old, put in the new, snug, not overtightened. Slowly
open the valve to let water in.

The boiler and the hot water heater are separate gas powered units. I
shut off the inlet value that's in front of the water feed pressure
valve. I then put a bucket under the pressure relief valve and pulled
up on the handle, about 1/2 gallon of water came out fast which leads
me to believe the system is still under pressure, yes? That would
imply that Jim is right that the whole system needs to be drained?
Should I keep draining out the water till it slows, or should I just
give up :-)
Thanks guys for your help....

"Speedy Jim" wrote in message
...
wrote:
Jim,
Thanks. It's gas hot water. I am probably in over my head. What do you
think a reasonable price to pay someone to replace the value is?
Thanks.


Call around and ask. Prices vary all over the country.

Also.....it's possible the valve is opening because
the pressure in the system really *is* too high.
This can happen when the water feed valve sticks open.

That's not the only reason.....

wrote in message
oups.com...
The boiler and the hot water heater are separate gas powered units. I
shut off the inlet value that's in front of the water feed pressure
valve. I then put a bucket under the pressure relief valve and pulled
up on the handle, about 1/2 gallon of water came out fast which leads
me to believe the system is still under pressure, yes? That would
imply that Jim is right that the whole system needs to be drained?
Should I keep draining out the water till it slows, or should I just
give up :-)
Thanks guys for your help....


Half gallon is not much. You have the potential to drain all the water
sitting in pipes above the valve. If it was under pressure, it would be
leaking out rather hard as soon as you cracked the valve or fitting open.
Much like a faucet.

Thanks Edwin. Since it's in the basement all the water is above this.
Should I try draining some more? It is coming out like a faucet turned
on about 75%. _stupid_ question...should I turn the furnace off? The
pilot light should stay on, yes? If drain the water out could I damage
anything? Thanks again.

wrote in message
oups.com...
Thanks Edwin. Since it's in the basement all the water is above this.
Should I try draining some more? It is coming out like a faucet turned
on about 75%. _stupid_ question...should I turn the furnace off? The
pilot light should stay on, yes? If drain the water out could I damage
anything? Thanks again.

Close the feed to the boiler, then drain

No reason to turn the pilot light off. Thee will still be some water in the
boiler so it will not be harmed in any way.

One you refill the system, there will be air in the lines. Someplace there
will be a drain, probably in the return line, that you can open to remove
the air.

You should call a qualified service technician. Boilers can become dangerous
if you don't know what your doing.

"Phil Yarbrough" wrote in message
...
You should call a qualified service technician. Boilers can become
dangerous
if you don't know what your doing.

He is working on a water valve, not a boiler. Service technician may not
know any more about it that he does. If the OP is not qualified, a plumber
would be a better option. I'd agree if he was fooling with ignition systems
or flames and gas valves.

Retail on the valve plus $50 an hour for labor.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


wrote in message
oups.com...
Jim,
Thanks. It's gas hot water. I am probably in over my head. What do you
think a reasonable price to pay someone to replace the value is?
Thanks.

Hi , hope you are having a nice day

On 28-May-05 At About 17:00:21, wrote to All
Subject: Replacing Furnace Press relief valve (Help!)

t From:

t Thanks Edwin. Since it's in the basement all the water is above
t this. Should I try draining some more? It is coming out like a
t faucet turned on about 75%. _stupid_ question...should I turn the
t furnace off? The pilot light should stay on, yes? If drain the
t water out could I damage anything? Thanks again.

You really should have it checked by a pro first. there may be a reason that
water is coming from the relief valve and it may not be defective. also, if
you drain the water it will also need to be bled after you are done and this
can be tricky for someone who doesn't know how to bleed it properly.



-= HvacTech2 =-


... "I bought instant water but I don't know what to add..."- s.w.

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Hi Edwin, hope you are having a nice day

On 29-May-05 At About 09:13:30, Edwin Pawlowski wrote to All
Subject: Replacing Furnace Press relief valve (Help!)

EP From: "Edwin Pawlowski"

EP "Phil Yarbrough" wrote in message
EP ...
You should call a qualified service technician. Boilers can become
dangerous if you don't know what your doing.

EP He is working on a water valve, not a boiler. Service technician may
EP not know any more about it that he does. If the OP is not
EP qualified, a plumber would be a better option. I'd agree if he was
EP fooling with ignition systems or flames and gas valves.

Yes Ed But remember that a boiler is running at usually 180 degrees and you
just told him there is no reason to shut down the pilot which also means it
could possibly come on. also what if he doesn't get all of the pressure out
and pulls the valve and sprays hot water on himself?


-= HvacTech2 =-


... "A friend of mine is in jail for counterfeiting pennies..."- s.w.

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"HvacTech2" wrote in message

Yes Ed But remember that a boiler is running at usually 180 degrees and
you
just told him there is no reason to shut down the pilot which also means
it
could possibly come on. also what if he doesn't get all of the pressure
out
and pulls the valve and sprays hot water on himself?


-= HvacTech2 =-

True, I should have mentioned the simple step of turning the heater off at
the switch. I know to do that, but not everyone would. This time of year
most of us have no need for heat, but some places still get chilly.

You may have a waterlogged expansion tank or a diaphram tank with a
ruptured diaphram. If that is the case, replacing the relief valve
won't help. You may also have a bad water feeder. You may have a bad
relief valve. Those are the most likely problems.

Stretch

Hi , hope you are having a nice day

On 31-May-05 At About 03:52:04, wrote to All
Subject: Replacing Furnace Press relief valve (Help!)

t From:

t Beating a dead horse here. The gauge on the side of the furnace says
t 21 PSI with a temp of 100. SInce I have the water intake shut off
t and water isn't spewing out the pressure relief valve can I assume
t the pressure relief valve is OK?

It probably is but there is still a problem or it wouldn't have leaked
before. you should have a pro check it and repair the problem.



-= HvacTech2 =-


... "Hit him again, I saw his foot move." -- L.A COP

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Beating a dead horse here. The gauge on the side of the furnace says
21 PSI with a temp of 100. SInce I have the water intake shut off and
water isn't spewing out the pressure relief valve can I assume the
pressure relief valve is OK?

In that case, it sounds like a bad water feeder or waterlogged
expansion tank or ruptured diaphram in your expansion tank.

Stretch

I'm going to agree. I've had the same issue with two previous heating
systems and it was the expansion tank diaphram both times. Yes, the
first time it happened I replaced a perfectly good over-pressure valve.
The tank is cheap enough to replace and if you're lucky, there will be
a shutoff valve right at the tank so you don't have to drain anything
nor rebleed the air out after.

Bobby