Recently I've found that in the morning my second floor bathroom sink will
produce warm, almost hot water from the cold tap for about 15 sec. in the
morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! - this
will sure help with my New England winter heating bills!". then I woke up...


It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a temp
regulating mixing valve which seems to be function properly - is that the
likely culprit? Would hot water run back into teh cold line and come out the
cold side 5 feet away? - WHy? the pressure is the same in the hot and cold
lines, isn't it?
I've never heard of this symptom - any one else??

Many TIA

Martin

In article , "mf" wrote:
Recently I've found that in the morning my second floor bathroom sink will
produce warm, almost hot water from the cold tap for about 15 sec. in the
morning.

"Recently" as in "since you turned the furnace on for the season", I'll bet...

It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a temp
regulating mixing valve which seems to be function properly - is that the
likely culprit? Would hot water run back into teh cold line and come out the
cold side 5 feet away? - WHy? the pressure is the same in the hot and cold
lines, isn't it?
I've never heard of this symptom - any one else??

My guess is that the supply lines to that sink pass close to a heat source.
Does your house by any chance have hot water or steam heat? If so, ten-to-one
IMO that your supply lines (or the cold one, at least) run right next to a
radiator in the next room.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

mf wrote:
Recently I've found that in the morning my second floor bathroom sink
will produce warm, almost hot water from the cold tap for about 15
sec. in the morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! -
this will sure help with my New England winter heating bills!". then
I woke up...

It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has
a temp regulating mixing valve which seems to be function properly -
is that the likely culprit? Would hot water run back into teh cold
line and come out the cold side 5 feet away? - WHy? the pressure is
the same in the hot and cold lines, isn't it?
I've never heard of this symptom - any one else??

Many TIA

Martin

I agree with Dough. It is likely picking up heat from a nearby heat
source like a hot water pipe, heating duct or pipe, etc.


--
Joseph Meehan

Dia duit

On Sat, 5 Nov 2005 09:51:42 -0500, "mf" wrote:

Recently I've found that in the morning my second floor bathroom sink will
produce warm, almost hot water from the cold tap for about 15 sec. in the
morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! - this
will sure help with my New England winter heating bills!". then I woke up...


It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a temp
regulating mixing valve which seems to be function properly - is that the
likely culprit? Would hot water run back into teh cold line and come out the
cold side 5 feet away? - WHy? the pressure is the same in the hot and cold
lines, isn't it?
I've never heard of this symptom - any one else??

I have, first hand, a little bit for a little while. I got stuck on
the same question you had. Isn't the hot water pressure no more,
maybe even less, that the cold water pressure?

Many TIA

Martin



Remove NOPSAM to email me. Please let
me know if you have posted also.

"mm" wrote in message
It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a
temp
regulating mixing valve which seems to be function properly - is that the
likely culprit? Would hot water run back into teh cold line and come out
the
cold side 5 feet away? - WHy? the pressure is the same in the hot and cold
lines, isn't it?
I've never heard of this symptom - any one else??

I have, first hand, a little bit for a little while. I got stuck on
the same question you had. Isn't the hot water pressure no more,
maybe even less, that the cold water pressure?

It is not a pressure thing, but a temperature thing. We all know hot air
rises. So does hot water. It can circulate on its own as long as there is
a temperature differential and equal pressure.

When no water is being drawn, the hot water pressure can rise above the
supply pressure due to expansion in the heater along with a no-return check
valve in the supply line. Expansion can back up the hot water into the cold
lines if you have a regulator on the water supply and no functional
expansion chamber. This can sometimes open the relief valve on the water
heater. Thermo-syphoning can also occur between hot and cold water lines,
particularly with mixing valves which can develop internal leaks between the
hot and cold supplies without noticeable leaking out the spout. Not real
common but also not real rare.
Don Young

"mm" wrote in message
...
On Sat, 5 Nov 2005 09:51:42 -0500, "mf" wrote:

Recently I've found that in the morning my second floor bathroom sink will
produce warm, almost hot water from the cold tap for about 15 sec. in the
morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! - this
will sure help with my New England winter heating bills!". then I woke
up...


It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a
temp
regulating mixing valve which seems to be function properly - is that the
likely culprit? Would hot water run back into teh cold line and come out
the
cold side 5 feet away? - WHy? the pressure is the same in the hot and cold
lines, isn't it?
I've never heard of this symptom - any one else??

I have, first hand, a little bit for a little while. I got stuck on
the same question you had. Isn't the hot water pressure no more,
maybe even less, that the cold water pressure?

Many TIA

Martin



Remove NOPSAM to email me. Please let
me know if you have posted also.

Mixing valve??? There is no such thing in that setup. It is simply a tee
joint.

There is no back-flow, since the other tap is closed, and even if open is
operating at the same pressure...


"mf" wrote in message
...
Recently I've found that in the morning my second floor bathroom sink will
produce warm, almost hot water from the cold tap for about 15 sec. in the
morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! - this
will sure help with my New England winter heating bills!". then I woke
up...

It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a
temp regulating mixing valve which seems to be function properly - is that
the likely culprit? Would hot water run back into teh cold line and come
out the cold side 5 feet away? - WHy? the pressure is the same in the hot
and cold lines, isn't it?
I've never heard of this symptom - any one else??

Many TIA

Martin

glenn P wrote:
Mixing valve??? There is no such thing in that setup. It is simply a tee
joint.

There is no back-flow, since the other tap is closed, and even if open is
operating at the same pressure...


"mf" wrote in message
...

Recently I've found that in the morning my second floor bathroom sink will
produce warm, almost hot water from the cold tap for about 15 sec. in the
morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! - this
will sure help with my New England winter heating bills!". then I woke
up...

It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a
temp regulating mixing valve which seems to be function properly - is that
the likely culprit? Would hot water run back into teh cold line and come
out the cold side 5 feet away? - WHy? the pressure is the same in the hot
and cold lines, isn't it?
I've never heard of this symptom - any one else??

Many TIA

Martin




You probably have some hot and cold water pipes running alongside and in
contact with each other causing the hot water pipe to transfer heat to
the cold water pipe, heating the water inside.

-The Plumbinator

This is quite commonly caused by internal leakage in any one of many kinds
of single handle faucets. It can be aggravated by expansion of hot water in
the heater where there is a check valve or regulator to prevent backup of
expanding hot water into the supply. Sometimes hot water will back up into
the cold water line feeding the heater, past where the cold water feeds
somewhere else. It is often possible to find the source of the problem by
careful feeling of the cold water lines.
Don Young

"glenn P" wrote in message
...
Mixing valve??? There is no such thing in that setup. It is simply a tee
joint.

There is no back-flow, since the other tap is closed, and even if open is
operating at the same pressure...


"mf" wrote in message
...
Recently I've found that in the morning my second floor bathroom sink
will produce warm, almost hot water from the cold tap for about 15 sec.
in the morning.

I'm thinking - "this is GREAT, the city is piping us out hot water! -
this will sure help with my New England winter heating bills!". then I
woke up...

It's an old sink with separate taps, no mixing valve.
Is this an indication of another mixing valve failing? My shower has a
temp regulating mixing valve which seems to be function properly - is
that the likely culprit? Would hot water run back into teh cold line and
come out the cold side 5 feet away? - WHy? the pressure is the same in
the hot and cold lines, isn't it?
I've never heard of this symptom - any one else??

Many TIA

Martin