Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?

Water meter pit is 175 feet from house. Pressure regulator is in
ground next to meter pit. City water pressure in meter put
approximately 100 PSI (according to city). Regulator is adjusted so
that incoming house water pressure is about 40 PSI as measured on
gauge in house. Pressure gauge in house is located on the house
piping as it enters basement from the outside. Downstream of this
gauge is check valve followed by thermal expansion tank. Also have
pressure gauge screwed into hot water tank drain valve. Note that
pressure readings on both gauges are approximately the same (within
the accuracies of the gauges).

During the day when we are home and using the water, pressure is
relatively constant from 38-42 PSI (within the accuracy of the gauge).
However in the morning before we use the water, the pressure has
risen overnight to 65-70 PSI.

Prior to leaving on a recent vacation, I shut valves in basement and
released pressure on house piping. The pressure on the incoming water
piping pressure gauge was 40 PSI and the pressure on the hot water
tank gauge was about 0 PSI. When I returned from vacation, the
pressure on the incoming water piping pressure gauge had risen to 70
PSI and the pressure on the hot water tank gauge was still at about 0
PSI.

Does this indicate a problem with the pressure regulator? If so, what
is going wrong with the regulator mechanism? Should I replace the
regulator?

David wrote:

Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?

SNIP

Yes. Even the tiniest of leakage past the regulator will slowly
increase downstream pressure. The valves are quite rugged and the
leakage could simply be due to dirt accumulation. But, hey, if you
have to remove the thing to clean it you might as well replace it.

Plan "B": Leave some faucet open to drip just enough to compensate.

Jim

According to Speedy Jim :
David wrote:

Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?

Yes. Even the tiniest of leakage past the regulator will slowly
increase downstream pressure. The valves are quite rugged and the
leakage could simply be due to dirt accumulation. But, hey, if you
have to remove the thing to clean it you might as well replace it.

Plan "B": Leave some faucet open to drip just enough to compensate.

Plan "C": ignore it. Unless you're worried about your plumbing rupturing
from 70PSI, it's not a problem. It'll instantly drop to 40PSI the moment
you start using it.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

"David" wrote in message
om...
Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?

Water meter pit is 175 feet from house. Pressure regulator is in
ground next to meter pit. City water pressure in meter put
approximately 100 PSI (according to city). Regulator is adjusted so
that incoming house water pressure is about 40 PSI as measured on
gauge in house. Pressure gauge in house is located on the house
piping as it enters basement from the outside. Downstream of this
gauge is check valve followed by thermal expansion tank. Also have
pressure gauge screwed into hot water tank drain valve. Note that
pressure readings on both gauges are approximately the same (within
the accuracies of the gauges).

During the day when we are home and using the water, pressure is
relatively constant from 38-42 PSI (within the accuracy of the gauge).
However in the morning before we use the water, the pressure has
risen overnight to 65-70 PSI.

Prior to leaving on a recent vacation, I shut valves in basement and
released pressure on house piping. The pressure on the incoming water
piping pressure gauge was 40 PSI and the pressure on the hot water
tank gauge was about 0 PSI. When I returned from vacation, the
pressure on the incoming water piping pressure gauge had risen to 70
PSI and the pressure on the hot water tank gauge was still at about 0
PSI.

Does this indicate a problem with the pressure regulator? If so, what
is going wrong with the regulator mechanism? Should I replace the
regulator?

Not necessarily. A lot of places pump at night into storage containers cause
it is cheaper.
You need a gauge on the line side to make the determination.

My pressure regulator is set at 40 psi at the main incoming line.


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thNot necessarily. A lot of places pump at night into storage containers cause
it is cheaper.

that wouldn't matter. that's the whole ppurpose of the regulator. No matter
what they (water co.) do on the other side of the meter, his pressure won't
rise above the 40p.s.i Of course it can drop though.

(Playintennis5274) wrote in message ...
thNot necessarily. A lot of places pump at night into storage containers cause
it is cheaper.

that wouldn't matter. that's the whole ppurpose of the regulator. No matter
what they (water co.) do on the other side of the meter, his pressure won't
rise above the 40p.s.i Of course it can drop though.

Unless the regulator is leaking slightly which is what it sounds like is happening.

Harry K

i know that. . . i was commenting on the guy who said some crap about pumps.

David wrote:
Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?



Based on the OP's thorough description I'd say it HAS to be an imperfect
presure reducing valve.

My mind started running off in the direction of the pressure reducing
valve being "perfect" but the incoming water was real cold, and the
house warmer, which could cause a pressure increase as the water warmed
up and expanded during the night. Then I went back and read that he had
a thermal expansion tank in the system, which killed that bright idea.

The pressure reducing valve must be weeping more than just a tiny bit,
because that thermal expansion tank (assuming it IS in proper shape)
would have to accept quite a bit of water before it'd "bottom out" and
permit the full line pressure.

Chances are a new valve, or a rebuild of the present one would reduce
the weepage to the point where the expansion tank could easily handle
it, certainly during an overnight idle period.

Jeff


--
My name is Jeff Wisnia and I approved this message....

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

Jeff Wisnia wrote in message ...
David wrote:
Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?



Based on the OP's thorough description I'd say it HAS to be an imperfect
presure reducing valve.

My mind started running off in the direction of the pressure reducing
valve being "perfect" but the incoming water was real cold, and the
house warmer, which could cause a pressure increase as the water warmed
up and expanded during the night. Then I went back and read that he had
a thermal expansion tank in the system, which killed that bright idea.

The pressure reducing valve must be weeping more than just a tiny bit,
because that thermal expansion tank (assuming it IS in proper shape)
would have to accept quite a bit of water before it'd "bottom out" and
permit the full line pressure.

Chances are a new valve, or a rebuild of the present one would reduce
the weepage to the point where the expansion tank could easily handle
it, certainly during an overnight idle period.

Jeff

Some more data. I tried the following. Open house faucet. Pressue
drops below 40 PSI, an expected result when using water. Then close
whole house shut off valve. Pressure should rise within several
seconds to line pressure comping out of regulator, right? Instead, I
have to wait several MINUTES for pressure to rise. Does this further
add to the evidence that the regulator shoudl be replaced?

"David" wrote in message
m...
Jeff Wisnia wrote in message
...
David wrote:
Problem: House pressure rises during the night from 40 PSI to 70 PSI.
Is incoming pressure regulator failing?



Based on the OP's thorough description I'd say it HAS to be an imperfect
presure reducing valve.

My mind started running off in the direction of the pressure reducing
valve being "perfect" but the incoming water was real cold, and the
house warmer, which could cause a pressure increase as the water warmed
up and expanded during the night. Then I went back and read that he had
a thermal expansion tank in the system, which killed that bright idea.

The pressure reducing valve must be weeping more than just a tiny bit,
because that thermal expansion tank (assuming it IS in proper shape)
would have to accept quite a bit of water before it'd "bottom out" and
permit the full line pressure.

Chances are a new valve, or a rebuild of the present one would reduce
the weepage to the point where the expansion tank could easily handle
it, certainly during an overnight idle period.

Jeff

Some more data. I tried the following. Open house faucet. Pressue
drops below 40 PSI, an expected result when using water. Then close
whole house shut off valve. Pressure should rise within several
seconds to line pressure comping out of regulator, right? Instead, I
have to wait several MINUTES for pressure to rise. Does this further
add to the evidence that the regulator shoudl be replaced?

A pressure regulator is meant to hold (regulate) the downstream pressure
when there is flow. When the system is shut down (faucet closed) the
regulator shuts down also. If the system pressure rises to the upstream
level it would mean (in my opinion) that there is some leakage past the
shutoff seals. To be sure, one would need a schematic of the regulating
valve to understand just how it works. Most regulators have a differential
area so that the forces acting on the valves are such that if the downstream
pressure rises above the controlled, or regulated pressure, the valve will
close.
MLD

MLD

A pressure regulator is meant to hold (regulate) the downstream pressure
when there is flow. When the system is shut down (faucet closed) the
regulator shuts down also. If the system pressure rises to the upstream
level it would mean (in my opinion) that there is some leakage past the
shutoff seals. To be sure, one would need a schematic of the regulating
valve to understand just how it works. Most regulators have a differential

flow or no flow a regulator maintains the it's set for. go to home depot & in
the sprinkler area they have little pressure guages for 10.00 BEFORE the
pressure regulator take a reading (at your meter u should have some little
threaded openings w/ little valve lever on the anti syphon valve) take a
reading, then AFTER the regulator find a spot and take a reading. But i can
guarentee you the regulator is slowly bypassing water. they're made of brass
and soft the seat or the seal surface has cecome imperfect and is leaking.