Water only, some rads piping hot
 

I have scoured this board to see if I can work out what's wrong with my
system, and while there are some posts that almost describe the problem
I thought i'd try my own query before calling in a heating engineer.

The basic problem is that some of the upstairs rads heat up when we are
running the CH on "water only" - from what I know of CH we have a pump
driven system, tanks in attic etc etc. Had new boiler and cylinder
installed about 18 months ago. I'm pretty sure we don't have a
non-return valve anywhere in the system, we have standard three port
valve near boiler and this is working fine.

I can understand the logic about an incorrectly plumbed tee from the
hot water return causing hot water to find its way into the rads....
but what worries me is that I would have expected to find the return
pipe from the rads was the one that heated up...instead it's the feed
pipe. This is a feature of the upstairs rads - particularly the two
bathrooms and the main bedroom.... and I don't think the bathroom rads
are plumbed into the hot water circuit if you see what I mean. They get
really hot....not just "trickle" of heat

Just can't work out what this is happening. If I thought it was only a
bit of poor plumbing I'd live with it by turning off the appropriate
rads, but it worries me that the heat is coming into the rads via the
return rather than the main how feed. I'm concerned there may be a
blockage somewhere and the radiator loop is acting as the escape route,
but that said, surely the hw thermostat would switch off the main
system?

Any ideas...??

J

Water only, some rads piping hot
 

wrote in message
oups.com...

I have scoured this board to see if I can work out what's wrong with my
system, and while there are some posts that almost describe the problem
I thought i'd try my own query before calling in a heating engineer.

The basic problem is that some of the upstairs rads heat up when we are
running the CH on "water only" - from what I know of CH we have a pump
driven system, tanks in attic etc etc. Had new boiler and cylinder
installed about 18 months ago. I'm pretty sure we don't have a
non-return valve anywhere in the system, we have standard three port
valve near boiler and this is working fine.

I can understand the logic about an incorrectly plumbed tee from the
hot water return causing hot water to find its way into the rads....
but what worries me is that I would have expected to find the return
pipe from the rads was the one that heated up...instead it's the feed
pipe. This is a feature of the upstairs rads - particularly the two
bathrooms and the main bedroom.... and I don't think the bathroom rads
are plumbed into the hot water circuit if you see what I mean. They get
really hot....not just "trickle" of heat

Just can't work out what this is happening. If I thought it was only a
bit of poor plumbing I'd live with it by turning off the appropriate
rads, but it worries me that the heat is coming into the rads via the
return rather than the main how feed. I'm concerned there may be a
blockage somewhere and the radiator loop is acting as the escape route,
but that said, surely the hw thermostat would switch off the main
system?

Any ideas...??

J


I had a similar problem a few years ago which took three British Gas
engineers to work out, It turned out to be a small neoprene valve buried
deep inside the boiler that had coroded and was allowing a bit of "feedback"
into the CH system.

Water only, some rads piping hot
 

Relatively new boiler (Dec 04) but can ask BG to look at that option.

Just checking around again and it might - repeat "might"! - be that the
main bathroom radiator's return pipe is warmer than I'd have expected
(it's almost completely covered by a box so not easy to grasp). If
that's where the hot water is entering the heating loop then I still
can't see why the other rads appear to be warming via the feed pipe.

I accept that my knowledge of CH is substantially lower than many of
the posters, so apologies if this all sounds stuoid!

J

wrote:
I have scoured this board to see if I can work out what's wrong with my
system, and while there are some posts that almost describe the problem
I thought i'd try my own query before calling in a heating engineer.

The basic problem is that some of the upstairs rads heat up when we are
running the CH on "water only" - from what I know of CH we have a pump
driven system, tanks in attic etc etc. Had new boiler and cylinder
installed about 18 months ago. I'm pretty sure we don't have a
non-return valve anywhere in the system, we have standard three port
valve near boiler and this is working fine.

I can understand the logic about an incorrectly plumbed tee from the
hot water return causing hot water to find its way into the rads....
but what worries me is that I would have expected to find the return
pipe from the rads was the one that heated up...instead it's the feed
pipe. This is a feature of the upstairs rads - particularly the two
bathrooms and the main bedroom.... and I don't think the bathroom rads
are plumbed into the hot water circuit if you see what I mean. They get
really hot....not just "trickle" of heat

Just can't work out what this is happening. If I thought it was only a
bit of poor plumbing I'd live with it by turning off the appropriate
rads, but it worries me that the heat is coming into the rads via the
return rather than the main how feed. I'm concerned there may be a
blockage somewhere and the radiator loop is acting as the escape route,
but that said, surely the hw thermostat would switch off the main
system?

Any ideas...??

J

Water only, some rads piping hot
 

In an earlier contribution to this discussion,
wrote:


The basic problem is that some of the upstairs rads heat up when we
are running the CH on "water only" - from what I know of CH we have a
pump driven system, tanks in attic etc etc. Had new boiler and
cylinder installed about 18 months ago. I'm pretty sure we don't have
a non-return valve anywhere in the system, we have standard three port
valve near boiler and this is working fine.


Do you have any evidence to substantiate your statement that the 3-port
valve is working fine? This is often the culprit in cases like this -
although this would usually result in *all* radiators getting hot - not just
those upstairs.
--
Cheers,
Roger
______
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Water only, some rads piping hot
 

Yes, it seems to be OK....reasons for such confidence a

- No real heat flow along the pipe that feeds the rads, just a small
bit of conduction

- Like you say all the rads would proabbly heat up

- And the man from BG tested it - with me watching!

J


Roger Mills wrote:
In an earlier contribution to this discussion,
wrote:


The basic problem is that some of the upstairs rads heat up when we
are running the CH on "water only" - from what I know of CH we have a
pump driven system, tanks in attic etc etc. Had new boiler and
cylinder installed about 18 months ago. I'm pretty sure we don't have
a non-return valve anywhere in the system, we have standard three port
valve near boiler and this is working fine.


Do you have any evidence to substantiate your statement that the 3-port
valve is working fine? This is often the culprit in cases like this -
although this would usually result in *all* radiators getting hot - not just
those upstairs.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Water only, some rads piping hot
 

Roger Mills wrote:
In an earlier contribution to this discussion,
wrote:

The basic problem is that some of the upstairs rads heat up when we
are running the CH on "water only" - from what I know of CH we have a
pump driven system, tanks in attic etc etc. Had new boiler and
cylinder installed about 18 months ago. I'm pretty sure we don't have
a non-return valve anywhere in the system, we have standard three port
valve near boiler and this is working fine.


Do you have any evidence to substantiate your statement that the 3-port
valve is working fine? This is often the culprit in cases like this -
although this would usually result in *all* radiators getting hot - not just
those upstairs.

If its leaky rather than jammed open, you tend to get a trickle of hot
into the rad system, and then gravity feed does the rest.

I had similar in my old installation..one or two rads would get warm to
hot under HW. Since one was the bathroom one, I never bothered to fix it.

Water only, some rads piping hot
 

In an earlier contribution to this discussion,
wrote:

Yes, it seems to be OK....reasons for such confidence a

- No real heat flow along the pipe that feeds the rads, just a small
bit of conduction

- Like you say all the rads would proabbly heat up

- And the man from BG tested it - with me watching!


It's gotta be right then, if BG tested it! g

If the valve *is* ok, it suggests that there's some sort of reverse - or one
pipe - circulation going on.

Looks like a floor-boards-up job, to identify exactly where all the pipes go
and thus to find where it's been plumbed wrongly.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Water only, some rads piping hot
 

Roger Mills wrote:

It's gotta be right then, if BG tested it! g

Yep! I know what you mean...! Note I put that third in my list!


If the valve *is* ok, it suggests that there's some sort of reverse - or one
pipe - circulation going on.

Looks like a floor-boards-up job, to identify exactly where all the pipes go
and thus to find where it's been plumbed wrongly.
Yes, coming to that conclusion.... but switching off all rads looks cheaper and less hassle!

Thanks, j
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!