I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

Does the flow increase again if you open the faced further? Mine does that
and I figure it is just a thermal thing.

R

On Sun, 19 Feb 2012 17:50:45 +0000 (UTC), DerbyDad03
wrote:

I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

What kind of piping?
You didn't mention the cold water side of the faucet.
Does the pressure drop when that's opened?

--Vic

"Roanin" wrote in
:


"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure but
as the water heats up, the pressure drops significantly, probably by
half within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture
in a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW
it's nothing new, I don't even recall when it first started...it's
been years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in
pressure is never noticed since they are maxed out at all times
anyway?

Thanks.

Does the flow increase again if you open the faced further? Mine does
that and I figure it is just a thermal thing.

R




Yes, I have to open the faucet much farther than the cold to get enough
hot water to make the water warm.

Vic Smith wrote in
news
On Sun, 19 Feb 2012 17:50:45 +0000 (UTC), DerbyDad03
wrote:

I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic
home-center utility sink fixture, the kind you can attach a garden
hose
to.

When I first turn on the hot water faucet I get a lot of pressure but
as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture
in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW
it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in
pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

What kind of piping?
You didn't mention the cold water side of the faucet.
Does the pressure drop when that's opened?

--Vic


1/2" copper.

The problem is only on the hot side at this one fixture.

On Sun, 19 Feb 2012 18:01:39 +0000 (UTC), DerbyDad03
wrote:



The problem is only on the hot side at this one fixture.

If it bothered me, I'd pull the stem and see if there's
debris/sediment in there.

--Vic

Vic Smith wrote in
:

On Sun, 19 Feb 2012 18:01:39 +0000 (UTC), DerbyDad03
wrote:



The problem is only on the hot side at this one fixture.

If it bothered me, I'd pull the stem and see if there's
debris/sediment in there.

--Vic



Already been done.

I had a worn washer and seat on the cold side, so I replaced the entire
stems on both sides a few months ago.

The problem was there before that and it's still there now. Replacing
the stems had no effect.

On Sun, 19 Feb 2012 18:24:03 +0000 (UTC), DerbyDad03
wrote:



Already been done.

I had a worn washer and seat on the cold side, so I replaced the entire
stems on both sides a few months ago.

The problem was there before that and it's still there now. Replacing
the stems had no effect.

Then what's left is an obstruction in the hot water piping before the
faucet.
Your hot water and cold water pressure should be the same, except for
a minor bit more on hot water when first opened due to expansion.
And that's insignificant.
Since the other faucets are low flow, they might have the same issue,
but it's not noticeable,
Depends on how the piping is branched and sized, but "normally" the
basement has slightly more pressure than upper floors due to head
pressure.
Barring sizing and branching, the only other place to look is the
inlet valve to the HW tank, or other valves unique to the hot water
side.

--Vic

On 2/19/2012 12:49 PM, Vic Smith wrote:
....

Then what's left is an obstruction in the hot water piping before the
faucet.
Your hot water and cold water pressure should be the same, except for
a minor bit more on hot water when first opened due to expansion.
And that's insignificant.
Since the other faucets are low flow, they might have the same issue,
but it's not noticeable,
Depends on how the piping is branched and sized, but "normally" the
basement has slightly more pressure than upper floors due to head
pressure.
Barring sizing and branching, the only other place to look is the
inlet valve to the HW tank, or other valves unique to the hot water
side.

You've asked indirectly, I was going to ask if by chance the hot water
side at this fixture is plumbed small for some reason.

What about the cutoff valve at the fixture--restriction there by any chance?

--

dpb wrote in :

On 2/19/2012 12:49 PM, Vic Smith wrote:
...

Then what's left is an obstruction in the hot water piping before the
faucet.
Your hot water and cold water pressure should be the same, except for
a minor bit more on hot water when first opened due to expansion.
And that's insignificant.
Since the other faucets are low flow, they might have the same issue,
but it's not noticeable,
Depends on how the piping is branched and sized, but "normally" the
basement has slightly more pressure than upper floors due to head
pressure.
Barring sizing and branching, the only other place to look is the
inlet valve to the HW tank, or other valves unique to the hot water
side.

You've asked indirectly, I was going to ask if by chance the hot water
side at this fixture is plumbed small for some reason.

What about the cutoff valve at the fixture--restriction there by any
chance?

--



All plumbing in the house is 1/2" copper. There's no down-sizing to this
fixture.

The shutoff for hot side of this faucet is a fully open ball valve.

How would a restriction in the plumbing to that side of the fixture
cause 20 seconds of high flow and then a descreasing amount as the water
gets hot?

Wouldn't the restriction be there at all times, always restricting the
flow?

On 2/19/2012 2:18 PM, DerbyDad03 wrote:
....

Wouldn't the restriction be there at all times, always restricting the
flow?

If it were a loose impediment, not necessarily...

--

On Sun, 19 Feb 2012 20:18:08 +0000 (UTC), DerbyDad03
wrote:


Wouldn't the restriction be there at all times, always restricting the
flow?

There's pressure, and flow (volume.)
When the faucet is off, all water in the piping gets pressurized.
But once the pressure has reduced by ejecting water from the faucet,
it takes sufficient flow to maintain the pressure

The timing doesn't seem right for that from what you said - 20
seconds?
But if you have an expansion tank, it may take that long to
depressurize. Then the flow restriction shows itself.
Since you have copper, a valve is the most likely suspect.
Another WAG is the HW tank is scaled up enough to restrict flow.
If you've pulled all the associated valve stems and verified the
valves are unrestricted, the only thing left is to take apart the
lines before and after the tank to pin it down.
I think you'll live with it as it is, but maybe I'm wrong.

--Vic

On 2/19/2012 2:34 PM, dpb wrote:
On 2/19/2012 2:18 PM, DerbyDad03 wrote:
....

Wouldn't the restriction be there at all times, always restricting the
flow?

If it were a loose impediment, not necessarily...

OBTW, you can eliminate/confirm the idea of the other faucets by
removing the aerator from one and testing. If it's flow-limiting so
don't notice the symptom, removing the restrictor will uncover that...

--

Vic Smith wrote in
:

On Sun, 19 Feb 2012 20:18:08 +0000 (UTC), DerbyDad03
wrote:


Wouldn't the restriction be there at all times, always restricting the
flow?

There's pressure, and flow (volume.)
When the faucet is off, all water in the piping gets pressurized.
But once the pressure has reduced by ejecting water from the faucet,
it takes sufficient flow to maintain the pressure

The timing doesn't seem right for that from what you said - 20
seconds?
But if you have an expansion tank, it may take that long to
depressurize. Then the flow restriction shows itself.
Since you have copper, a valve is the most likely suspect.
Another WAG is the HW tank is scaled up enough to restrict flow.
If you've pulled all the associated valve stems and verified the
valves are unrestricted, the only thing left is to take apart the
lines before and after the tank to pin it down.
I think you'll live with it as it is, but maybe I'm wrong.

--Vic

Well, I don’t have an expansion tank, so we can eliminate that as part
of the situation.

As far as eliminating the ball valve shut off as a possible cause, that
could easily be done with a couple of Sharkbites and some Pex as a
bypass.

In fact, I could flush the line by the tapping in before the shutoff and
letting the Pex hang in the sink as I turn the main back on. Then I
could tap in before the faucet (creating the bypass) then let the system
pressurize and open the faucet to see what happens.

I’m not sure what you mean by "take apart the lines before and after the
tank to pin it down."

On Sun, 19 Feb 2012 21:48:29 +0000 (UTC), DerbyDad03
wrote:


As far as eliminating the ball valve shut off as a possible cause, that
could easily be done with a couple of Sharkbites and some Pex as a
bypass.

In fact, I could flush the line by the tapping in before the shutoff and
letting the Pex hang in the sink as I turn the main back on. Then I
could tap in before the faucet (creating the bypass) then let the system
pressurize and open the faucet to see what happens.

Im not sure what you mean by "take apart the lines before and after the
tank to pin it down."


Your bypass idea is breaking into (I used "take apart".) the line
after the tank.
If you have the same flow problem, the next step would be to check
flow going into the tank,
If that's good it's the tank restricting the flow.
Don't know how your valves are set up.
My tanks have always had a valve only on the outlet side.
But some have both.
Also have no stop valves on my laundry tub.
And I never worked with copper, just galvanized.
Sounds like you know the process.

--Vic

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.


I have seen hot water faucets that reduce the flow as the water gets hot. I
have always blamed a design flaw that allows the stem to expand in length
with the increase in heat so that the flow slows down as the stem slowly
moves closer to the seat. It also could be the washer expanding as well,
compounding the problem. Newer faucets that don't use a stem in the water
flow don't seem to have the same problems.

First, try with the aerator off. (OK, laundry sink not likely to have
aerator).

Second, might be a faucet washer that is expanding when warm. Or loose, and
blocking the water passage.

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

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

Sounds like a faucet washer expanding when heated, or maybe loose and needs
to be tightned down. I'd think to replace both faucet washers while you have
the water off.

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

"DerbyDad03" wrote in message
. 90...

1/2" copper.

The problem is only on the hot side at this one fixture.

Might be problems with a shut off faucet, upstream?

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

"DerbyDad03" wrote in message
. 90...

Already been done.

I had a worn washer and seat on the cold side, so I replaced the entire
stems on both sides a few months ago.

The problem was there before that and it's still there now. Replacing
the stems had no effect.

And impediment that expands when it gets hot.

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

"dpb" wrote in message ...
On 2/19/2012 2:18 PM, DerbyDad03 wrote:
....

Wouldn't the restriction be there at all times, always restricting the
flow?

If it were a loose impediment, not necessarily...

--

On 2/19/2012 6:24 PM, EXT wrote:

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.


I have seen hot water faucets that reduce the flow as the water gets
hot. I have always blamed a design flaw that allows the stem to expand
in length with the increase in heat so that the flow slows down as the
stem slowly moves closer to the seat. It also could be the washer
expanding as well, compounding the problem. Newer faucets that don't use
a stem in the water flow don't seem to have the same problems.

Some water heaters have a sensor that adds cold water to the hot water
if it too hot. Mine has that feature. I also experience the hot water
flow slowing down as a few seconds after I turn on the hot water.
I had this situation on my previous faucet and I just put in a new
faucet, different brand, and it does the same thing. This only happens
in the kitchen.

Chuck wrote in :

On 2/19/2012 6:24 PM, EXT wrote:

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure
but as the water heats up, the pressure drops significantly,
probably by half within 20 seconds.

I don't experience any pressure drop at any other fixture, not at
the single handle sinks or showers fixtures nor at the two-handle
fixture in a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW
it's nothing new, I don't even recall when it first started...it's
been years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow
so that they never allow as much water to flow so that the drop in
pressure is never noticed since they are maxed out at all times
anyway?

Thanks.


I have seen hot water faucets that reduce the flow as the water gets
hot. I have always blamed a design flaw that allows the stem to
expand in length with the increase in heat so that the flow slows
down as the stem slowly moves closer to the seat. It also could be
the washer expanding as well, compounding the problem. Newer faucets
that don't use a stem in the water flow don't seem to have the same
problems.

Some water heaters have a sensor that adds cold water to the hot water
if it too hot. Mine has that feature. I also experience the hot water
flow slowing down as a few seconds after I turn on the hot water.
I had this situation on my previous faucet and I just put in a new
faucet, different brand, and it does the same thing. This only happens
in the kitchen.


My hot water heater has no such sensor, so that’s not the cause of my
problem.

"Robert Green" wrote in
:

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure but
as the water heats up, the pressure drops significantly, probably by
half within 20 seconds.

I have exactly the same issue. I believe it's just the valve
components heating and expanding and then restricting the flow. The
test is this: Open the valve all the way to start. Does the flow
restrict when it warms up? I would guess not. It only happens to me
if I open the valve partially. As soon as the partially opened valve
body becomes warm, it expands and impedes the flow. My problem
started when I replaced the conical washer inside the valve stem with
one from a cheap kit of a few dozen washers or so. I assume the
washer's made of material that expands a bit when it's warm.

Try the "wide open" test and see if there's any drop in the flow rate
as hot water hits the valve. I find it only happens if I open the
valve a quarter turn or so, not when wide open.

--
Bobby G.




The flow does not seem to decrease with the valve fully open, but that’s
just as much a PITA. I rarely need the hot on full blast, so it’s either
turn it on more when the flow decreases or turn it down once the hot
water reaches the faucet.

Since full-on wastes water, I think I’ll opt for turning it up until I
decide to investigate further.

On Feb 20, 7:43*pm, DerbyDad03 wrote:
Chuck wrote :





On 2/19/2012 6:24 PM, EXT wrote:

"DerbyDad03" wrote in message
4.90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure
but as the water heats up, the pressure drops significantly,
probably by half within 20 seconds.

I don't experience any pressure drop at any other fixture, not at
the single handle sinks or showers fixtures nor at the two-handle
fixture in a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW
it's nothing new, I don't even recall when it first started...it's
been years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow
so that they never allow as much water to flow so that the drop in
pressure is never noticed since they are maxed out at all times
anyway?

Thanks.

I have seen hot water faucets that reduce the flow as the water gets
hot. I have always blamed a design flaw that allows the stem to
expand in length with the increase in heat so that the flow slows
down as the stem slowly moves closer to the seat. It also could be
the washer expanding as well, compounding the problem. Newer faucets
that don't use a stem in the water flow don't seem to have the same
problems.

Some water heaters have a sensor that adds cold water to the hot water
if it too hot. Mine has that feature. I also experience the hot water
flow slowing down as a few seconds after I turn on the hot water.
I had this situation on my previous faucet and I just put in a new
faucet, different brand, and it does the same thing. This only happens
in the kitchen.

My hot water heater has no such sensor, so that’s not the cause of my
problem.- Hide quoted text -

- Show quoted text -

I would turn the water off. Then I would disconnect the water at the
input to the faucet, then have someone turn the water back on and see
if I had a good flow of hot water. I bet there is some sort of
obstruction in the hot water line.

"DerbyDad03" wrote in message
0...
"Robert Green" wrote in
:

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure but
as the water heats up, the pressure drops significantly, probably by
half within 20 seconds.

I have exactly the same issue. I believe it's just the valve
components heating and expanding and then restricting the flow. The
test is this: Open the valve all the way to start. Does the flow
restrict when it warms up? I would guess not. It only happens to me
if I open the valve partially. As soon as the partially opened valve
body becomes warm, it expands and impedes the flow. My problem
started when I replaced the conical washer inside the valve stem with
one from a cheap kit of a few dozen washers or so. I assume the
washer's made of material that expands a bit when it's warm.

Try the "wide open" test and see if there's any drop in the flow rate
as hot water hits the valve. I find it only happens if I open the
valve a quarter turn or so, not when wide open.

--
Bobby G.




The flow does not seem to decrease with the valve fully open, but that's
just as much a PITA.

But I think it's an important clue as to what's happening, PITA or not.

I rarely need the hot on full blast, so it's either
turn it on more when the flow decreases or turn it down once the hot
water reaches the faucet.

I've opted for resetting the flow rate once the valve has warmed up. Since
that works, I don't really see how it could be an impediment in the line or
anything but a bad valve or washer.

Since full-on wastes water, I think I'll opt for turning it up until I
decide to investigate further.

I would pull it and replace the washer, which is on my list of things to do.
My issues started after I replaced an old washer. It's also possible that
there's an impediment in the pipe that expands when warm. I once extracted
an acorn(!) from behind the kitchen faucet aerator after I noticed an
intermittent rise and fall of the flow rate. As it rotated around in the
faucet arm, it varied the flow (it was not perfectly round). FWIW, I
installed a water filter right after that incident. (-: But I don't think
that's your problem.

Since the slop sink valves are usually located at one of the lowest points
in the whole piping system, garbage in the lines could easily find its way
down there. I'm still of the mind that it's the faucet washer. Was it flat
or conical?

Since it doesn't exhibit the problem at maximum flow, it does seem to me to
be the valve washer. Although the initial valve setting allows a slow flow,
once the washer and seat heat up, that small gap narrows and the flow slows.
On my sink, the flow will go from perhaps a half gallon per minute to a very
slow trickle - just a few drops.

Good luck. I haven't fixed it because it keeps me from wasting the hot
water accidentally. (-: It's like having a faucet ghost saying "you didn't
mean to leave the hot water running full blast, did you?" Of course, I have
managed to leave it trickling hot water when I though the valve was closed.

--
Bobby G.

"Robert Green" wrote in
:

"DerbyDad03" wrote in message
0...
"Robert Green" wrote in
:

"DerbyDad03" wrote in message
. 90...
I've got a hot water pressure problem but only at one fixtu the
2 handle non-low flow fixture at my basement utility sink. It's
your basic home-center utility sink fixture, the kind you can
attach a garden hose to.

When I first turn on the hot water faucet I get a lot of pressure
but as the water heats up, the pressure drops significantly,
probably by half within 20 seconds.

I have exactly the same issue. I believe it's just the valve
components heating and expanding and then restricting the flow.
The test is this: Open the valve all the way to start. Does the
flow restrict when it warms up? I would guess not. It only
happens to me if I open the valve partially. As soon as the
partially opened valve body becomes warm, it expands and impedes
the flow. My problem started when I replaced the conical washer
inside the valve stem with one from a cheap kit of a few dozen
washers or so. I assume the washer's made of material that expands
a bit when it's warm.

Try the "wide open" test and see if there's any drop in the flow
rate as hot water hits the valve. I find it only happens if I open
the valve a quarter turn or so, not when wide open.

--
Bobby G.




The flow does not seem to decrease with the valve fully open, but
that's just as much a PITA.

But I think it's an important clue as to what's happening, PITA or
not.

I rarely need the hot on full blast, so it's either
turn it on more when the flow decreases or turn it down once the hot
water reaches the faucet.

I've opted for resetting the flow rate once the valve has warmed up.
Since that works, I don't really see how it could be an impediment in
the line or anything but a bad valve or washer.

Since full-on wastes water, I think I'll opt for turning it up until
I decide to investigate further.

I would pull it and replace the washer, which is on my list of things
to do. My issues started after I replaced an old washer. It's also
possible that there's an impediment in the pipe that expands when
warm. I once extracted an acorn(!) from behind the kitchen faucet
aerator after I noticed an intermittent rise and fall of the flow
rate. As it rotated around in the faucet arm, it varied the flow (it
was not perfectly round). FWIW, I installed a water filter right
after that incident. (-: But I don't think that's your problem.

Since the slop sink valves are usually located at one of the lowest
points in the whole piping system, garbage in the lines could easily
find its way down there. I'm still of the mind that it's the faucet
washer. Was it flat or conical?

Since it doesn't exhibit the problem at maximum flow, it does seem to
me to be the valve washer. Although the initial valve setting allows
a slow flow, once the washer and seat heat up, that small gap narrows
and the flow slows. On my sink, the flow will go from perhaps a half
gallon per minute to a very slow trickle - just a few drops.

Good luck. I haven't fixed it because it keeps me from wasting the
hot water accidentally. (-: It's like having a faucet ghost saying
"you didn't mean to leave the hot water running full blast, did you?"
Of course, I have managed to leave it trickling hot water when I
though the valve was closed.

--
Bobby G.




As I said in an earlier post, I've replaced the entire stem, including
the washer and seat. The cold side needed a new seat so I rebuilt the
entire faucet.

The problem was there before I replaced the stem and it's still there
now.

I guess I can try another washer anyway.

"hr(bob) " wrote in
:

On Feb 20, 7:43*pm, DerbyDad03 wrote:
Chuck wrote :





On 2/19/2012 6:24 PM, EXT wrote:

"DerbyDad03" wrote in message
4.90...
I've got a hot water pressure problem but only at one fixtu
the 2 handle non-low flow fixture at my basement utility sink.
It's your basic home-center utility sink fixture, the kind you
can attach a garden hose to.

When I first turn on the hot water faucet I get a lot of pressure
but as the water heats up, the pressure drops significantly,
probably by half within 20 seconds.

I don't experience any pressure drop at any other fixture, not at
the single handle sinks or showers fixtures nor at the two-handle
fixture in a 2nd floor bathroom.

It's only at the utility sink where I experience this problem.
BTW it's nothing new, I don't even recall when it first
started...it's been years. I'm just finally getting around to
asking about it.

Any ideas? Could it be that all of the other fixtures are low
flow so that they never allow as much water to flow so that the
drop in pressure is never noticed since they are maxed out at all
times anyway?

Thanks.

I have seen hot water faucets that reduce the flow as the water
gets hot. I have always blamed a design flaw that allows the stem
to expand in length with the increase in heat so that the flow
slows down as the stem slowly moves closer to the seat. It also
could be the washer expanding as well, compounding the problem.
Newer faucets that don't use a stem in the water flow don't seem
to have the same problems.

Some water heaters have a sensor that adds cold water to the hot
water if it too hot. Mine has that feature. I also experience the
hot water flow slowing down as a few seconds after I turn on the
hot water. I had this situation on my previous faucet and I just
put in a new faucet, different brand, and it does the same thing.
This only happens in the kitchen.

My hot water heater has no such sensor, so that’s not the cause of my
problem.- Hide quoted text -

- Show quoted text -

I would turn the water off. Then I would disconnect the water at the
input to the faucet, then have someone turn the water back on and see
if I had a good flow of hot water. I bet there is some sort of
obstruction in the hot water line.

That was suggested earlier in the thread.

Unfortunately, it's all sweated - and from underneath - so it's going to
involve cutting pipes, extra fittings to run the water into the sink,
etc.

Doable, but a major PITA.

"DerbyDad03" wrote in message

stuff snipped

As I said in an earlier post, I've replaced the entire stem, including
the washer and seat. The cold side needed a new seat so I rebuilt the
entire faucet.

I'm sorry I missed it. You somehow managed to fix your newsreader so that
it automatically inserts the symbols again. That's worth something. (-"

The problem was there before I replaced the stem and it's still there
now.

I thought this had just started. I still don't see how it could be much
*other* than the valve if the full open flow isn't impeded. If there was
something like the acorn in the line that I had, it would create a problem
no matter what the flow rate, IMHO.

I guess I can try another washer anyway.

If it really bothered me, I'd probably replace the whole valve. I just live
with it.

Let me pose this question. After the valve's been running wide open for a
minute and the entire valve body has heated up, can you then adjust it to a
low flow and have it stay at the selected flow rate? That would tend to
support the theory that something's expanding inside the valve. There's
probably one factory in China making all the valve washers in the world
nowadays so it replacing it might not have any benefit. Maybe they're using
melamine to make them . . . (-:

--
Bobby G.

DerbyDad03 wrote:
Vic Smith wrote in
news
On Sun, 19 Feb 2012 17:50:45 +0000 (UTC), DerbyDad03
wrote:

I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure
but as the water heats up, the pressure drops significantly,
probably by half within 20 seconds.

I don't experience any pressure drop at any other fixture, not at
the single handle sinks or showers fixtures nor at the two-handle
fixture in a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW
it's nothing new, I don't even recall when it first started...it's
been years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow
so that they never allow as much water to flow so that the drop in
pressure is never noticed since they are maxed out at all times
anyway?

Thanks.

What kind of piping?
You didn't mention the cold water side of the faucet.
Does the pressure drop when that's opened?

--Vic


1/2" copper.

The problem is only on the hot side at this one fixture.

Is the supply hose on the hot side either very long or very small inside
diameter?

On Feb 19, 12:55*pm, "Roanin" wrote:
"DerbyDad03" wrote in message

. 90...



I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

Does the flow increase again if you open the faced further? Mine does that
and I figure it is just a thermal thing.

R- Hide quoted text -

- Show quoted text -

I've seen other faucets do that too. My guess would
be that the washer in the faucet expands with the
temp increase, causing the flow to decrease.

As long as you can get a high flow rate with the
faucet wide open, you can pretty much rule out
kinked pipes somewhere, obstructions, etc.
I'd try changing the washer and see what happens.

On Feb 23, 11:15*am, "Bob F" wrote:
DerbyDad03 wrote:
Vic Smith wrote in
news

On Sun, 19 Feb 2012 17:50:45 +0000 (UTC), DerbyDad03
wrote:

I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your
basic home-center utility sink fixture, the kind you can attach a
garden hose to.

When I first turn on the hot water faucet I get a lot of pressure
but as the water heats up, the pressure drops significantly,
probably by half within 20 seconds.

I don't experience any pressure drop at any other fixture, not at
the single handle sinks or showers fixtures nor at the two-handle
fixture in a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW
it's nothing new, I don't even recall when it first started...it's
been years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow
so that they never allow as much water to flow so that the drop in
pressure is never noticed since they are maxed out at all times
anyway?

Thanks.

What kind of piping?
You didn't mention the cold water side of the faucet.
Does the pressure drop when that's opened?

--Vic

1/2" copper.

The problem is only on the hot side at this one fixture.

Is the supply hose on the hot side either very long or very small inside
diameter?- Hide quoted text -

- Show quoted text -

What supply hose?

As I said earlier, it's all plumbed with 1/2 copper.

On Feb 23, 11:40*am, "
wrote:
On Feb 19, 12:55*pm, "Roanin" wrote:





"DerbyDad03" wrote in message

.90...

I've got a hot water pressure problem but only at one fixtu the 2
handle non-low flow fixture at my basement utility sink. It's your basic
home-center utility sink fixture, the kind you can attach a garden hose
to.

When I first turn on the hot water faucet I get a lot of pressure but as
the water heats up, the pressure drops significantly, probably by half
within 20 seconds.

I don't experience any pressure drop at any other fixture, not at the
single handle sinks or showers fixtures nor at the two-handle fixture in
a 2nd floor bathroom.

It's only at the utility sink where I experience this problem. BTW it's
nothing new, I don't even recall when it first started...it's been
years. I'm just finally getting around to asking about it.

Any ideas? Could it be that all of the other fixtures are low flow so
that they never allow as much water to flow so that the drop in pressure
is never noticed since they are maxed out at all times anyway?

Thanks.

Does the flow increase again if you open the faced further? Mine does that
and I figure it is just a thermal thing.

R- Hide quoted text -

- Show quoted text -

I've seen other faucets do that too. *My guess would
be that the washer in the faucet expands with the
temp increase, causing the flow to decrease.

As long as you can get a high flow rate with the
faucet wide open, you can pretty much rule out
kinked pipes somewhere, obstructions, etc.
I'd try changing the washer and see what happens.- Hide quoted text -

- Show quoted text -

I know that everyone is trying to help, but I've already posted a
couple of times that the stems, washers and seats were already
changed.

The problem existed before the rebuild and remains afterwards.

I guess it's possible that the washer expansion problem "followed" the
stem change i.e. faulty washers before and after. If that's the case,
I guess I should buy washers from a different store and hope that they
use a different brand/manufacturer.

I guess it's worth a try.

On 2/23/2012 12:48 PM, DerbyDad03 wrote:
....

As I said earlier, it's all plumbed with 1/2 copper.

Did you ever do the experiment about removing flow restrictor in another
faucet to see if apparent full-flow there is an aberration of the
restriction in them as opposed to this one?

--

"DerbyDad03" wrote in message
. 90...
dpb wrote in :

stuff snipped

You've asked indirectly, I was going to ask if by chance the hot water
side at this fixture is plumbed small for some reason.

What about the cutoff valve at the fixture--restriction there by any
chance?

All plumbing in the house is 1/2" copper. There's no down-sizing to this
fixture.

The shutoff for hot side of this faucet is a fully open ball valve.

How would a restriction in the plumbing to that side of the fixture
cause 20 seconds of high flow and then a descreasing amount as the water
gets hot?

Wouldn't the restriction be there at all times, always restricting the
flow?

That's what I would think. I think you've proved that it's the damn valve.
Either the stem or the washer or both are expanding when then get warm,
changing the very small opening that allows water to pass. I'm not sure how
you prove that conclusively beyond what you've already done. Your changeout
having no effect implies either there's a problem elsewhere (which I tend to
doubt) or that there's a flaw in slop sink faucet design or washer
manufacture. Does anyone make a ball valve for a faucet? It seems that
would be the only type of valve that would be immune to thermal issues like
this. You could test that by leaving the sink valve wide open so you can
try controlling it with the ball shutoff valve. If the ball valve can
maintain a low, constant flow, I think it would tend to validate the thermal
theory about the washer/stem expanding when warmed up.

What happens if the sink's hot side has been running (warmed up) for a
minute or two? Can you shut it off and then reopen it to a low flow rate
without seeing any reduction? I would think that test would confirm the
thermal theory. Of course, that doesn't actually *solve* the problem, but
isolating and ID'ing it is the first step.

--
Bobby G.

"DerbyDad03" wrote in message

stuff snipped

The flow does not seem to decrease with the valve fully open, but that's
just as much a PITA. I rarely need the hot on full blast, so it's either
turn it on more when the flow decreases or turn it down once the hot
water reaches the faucet.

Since full-on wastes water, I think I'll opt for turning it up until I
decide to investigate further.

I've been down in the basement running hot water flow tests on the slop
sink. I made note of the position of the handle at the "end flow rate" -
the one I want once the valve has warmed up. That turns out to be
consistently at the 11 O'clock position of the handle. If I open it up to
start at that position, the cold water flushes out quickly and when the hot
water begins to flow the valve goes from fast flowing to exactly the flow
rate I wanted in the first place. It turns out to be a good thing because I
end up getting hot water faster. The cold flows quickly, the valve heats up
and then the water flow becomes something like a quart a minute. You've
solved my problem.

(-: It's a feature, not a bug!

--
Bobby G.

dpb wrote in :

On 2/23/2012 12:48 PM, DerbyDad03 wrote:
...

As I said earlier, it's all plumbed with 1/2 copper.

Did you ever do the experiment about removing flow restrictor in another
faucet to see if apparent full-flow there is an aberration of the
restriction in them as opposed to this one?

--



Yes I did. Well, I removed the aerator on a 2 handled bathroom fixture.

If that removed the flow restrictor, then yes, I did.

Full flow right from the start.