I'm moving into a new home that has an old boiler, the label on it
says "Thorn EMI Heating Limited M56/76 & M80/100 gas boilers". There
is a cylinder above it in the bedroom and in the attic there is a cold-
water cistern and a feed-and-expansion cistern. I'm after some general
advice (be gentle on my I am totally ignorant re central heating/water
systems!):

1. The timer on the system is not working - could I fit a modern
thermostat and timer to the boiler?
2. Alternatively, if the boiler is replaced would I need to replace
all the radiators as well? Is there a difference between modern
pipework and older (possibly over 20 years old) pipework diameter?
3. Can the cylinder be moved into the attic? What affect would this
have on the water cisterns already in the attic?
4. If I replace the boiler, what should I replace it with? I think a
combi would be out of the question as the house is a large 5-
bedroomed, with a couple of bathrooms.

Thanks very much

In an earlier contribution to this discussion,
tvmo wrote:

I'm moving into a new home that has an old boiler, the label on it
says "Thorn EMI Heating Limited M56/76 & M80/100 gas boilers". There
is a cylinder above it in the bedroom and in the attic there is a
cold- water cistern and a feed-and-expansion cistern. I'm after some
general advice (be gentle on my I am totally ignorant re central
heating/water systems!):

1. The timer on the system is not working - could I fit a modern
thermostat and timer to the boiler?

Probably, but we'd need to know a lot more about the pipework layout before
being able to recommend the best solution. How many water pipes connect to
the boiler, and what is their diameter? Are there any motorised valves? If
so, how many and what type (2-port or 3 port)?

2. Alternatively, if the boiler is replaced would I need to replace
all the radiators as well? Is there a difference between modern
pipework and older (possibly over 20 years old) pipework diameter?

Not unless the current radiators are shot - which they *may* be if the
system has been run for years without inhibitor, so that they have rusted
inside. In this case, fitting a new boiler - which will almost certainly use
a non-vented (pressurised) system - the extra pressure may just be the last
straw which may cause them to start leaking. On the other hand, they may be
perfectly ok.

Another consideration is that a new condensing boiler needs to run at a
lower flow temperature than your existing boiler in order to maximise its
efficiency. So if your existing radiators are only just adequate in terms of
heat output, you may need bigger ones (or probably the same physical size
but with fins on the back) to get the same heat output at a lower water
temperature. On the other hand, the standard of insulation of the walls,
windows and attic may well have been improved since the system was
installed, making the existing rads more than adequate.

Don't worry about pipe sizes. The original system may use imperial pipe
sizes - 1", 3/4", 1/2" (though probably not if it's only 20 years old) - but
it's easy enough to join up to the equivalent metric sizes of 28mm, 22mm and
15mm. [1]

3. Can the cylinder be moved into the attic? What affect would this
have on the water cisterns already in the attic?

It *could* but you'd have to make sure that you had an adequate structure to
support the weight. You'd also need to raise the cold header hank to be
higher than the cylinder - for which you may or may not not have enough
headroom.

4. If I replace the boiler, what should I replace it with? I think a
combi would be out of the question as the house is a large 5-
bedroomed, with a couple of bathrooms.


There are plenty of non-combi boilers around which will suit your purpose,
and give you central heating plus lashings of stored hot water. To satisfy
current building regs it will have to be a high efficiency (which
effectively means condensing) boiler, and you'll have to update the controls
and room and cylinder thermostats to provide boiler interlock. In other
words, the boiler must shut down completely and not keep keep firing to keep
itself warm once both the CH and HW demands are satisfied. It also makes
sense (not sure if it's mandatory?) to fit TRVs to most of the radiators.

[1] These sizes may not *look* equivalent (based on 1" = 25.4mm) but they
are actually much closer than that because imperial pipes are measured on
the *inside* and metric on the *outside*.
--
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!

tvmo wrote:

I'm moving into a new home that has an old boiler, the label on it
says "Thorn EMI Heating Limited M56/76 & M80/100 gas boilers". There
is a cylinder above it in the bedroom and in the attic there is a cold-
water cistern and a feed-and-expansion cistern. I'm after some general
advice (be gentle on my I am totally ignorant re central heating/water
systems!):

This will give you the background info:

http://wiki.diyfaq.org.uk/index.php?...entral_Heating
http://wiki.diyfaq.org.uk/index.php?..._Water_Systems

In general terms:

1. The timer on the system is not working - could I fit a modern
thermostat and timer to the boiler?

More than likely.

2. Alternatively, if the boiler is replaced would I need to replace
all the radiators as well? Is there a difference between modern
pipework and older (possibly over 20 years old) pipework diameter?

Unless you have a particularly unusual design then chances are what you
have will be fine if not too badly corroded. Modern systems are usually
designed to run slightly cooler than older ones, so you may need to swap
some rads about if you find some rooms are on the cool side and
balancing alone does not fix it.

3. Can the cylinder be moved into the attic? What affect would this
have on the water cisterns already in the attic?

It can, but the cold water cistern would need to be raised up above it
on a suitable platform.

4. If I replace the boiler, what should I replace it with? I think a
combi would be out of the question as the house is a large 5-
bedroomed, with a couple of bathrooms.

This is a deep question. Have a read of the links above to get familiar
with the options.

--
Cheers,

John.

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On Mon, 24 Mar 2008 02:43:24 -0700, tvmo wrote:

I'm moving into a new home that has an old boiler, the label on it says
"Thorn EMI Heating Limited M56/76 & M80/100 gas boilers". There is a
cylinder above it in the bedroom and in the attic there is a cold- water
cistern and a feed-and-expansion cistern. I'm after some general advice
(be gentle on my I am totally ignorant re central heating/water
systems!):

1. The timer on the system is not working - could I fit a modern
thermostat and timer to the boiler?
2. Alternatively, if the boiler is replaced would I need to replace all
the radiators as well? Is there a difference between modern pipework and
older (possibly over 20 years old) pipework diameter? 3. Can the
cylinder be moved into the attic? What affect would this have on the
water cisterns already in the attic? 4. If I replace the boiler, what
should I replace it with? I think a combi would be out of the question
as the house is a large 5- bedroomed, with a couple of bathrooms.

Thanks very much

Try the BoilerChoice FAQ below. The wiki pages are good too.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

Thanks very much for taking the time to reply.

"Not unless the current radiators are shot - which they *may* be if
the
system has been run for years without inhibitor, so that they have
rusted
inside. In this case, fitting a new boiler - which will almost
certainly use
a non-vented (pressurised) system - the extra pressure may just be the
last
straw which may cause them to start leaking. On the other hand, they
may be
perfectly ok. " - Is there a test that can be performed to check for
the integrity of the radiators/pipework?

Any recommendations on brands of boilers?

Thanks again

In an earlier contribution to this discussion,
tvmo wrote:

Thanks very much for taking the time to reply.

"Not unless the current radiators are shot - which they *may* be if
the
system has been run for years without inhibitor, so that they have
rusted
inside. In this case, fitting a new boiler - which will almost
certainly use
a non-vented (pressurised) system - the extra pressure may just be the
last
straw which may cause them to start leaking. On the other hand, they
may be
perfectly ok. " - Is there a test that can be performed to check for
the integrity of the radiators/pipework?

You can pressure test the whole system with air, using something like
http://tinyurl.com/3aqgox

You would, of course, have to put temporary caps on the feed and vent pipes.

If you're removing all the radiators to give them a good flush out with a
hosepipe (very worthwhile if you're upgrading your system) it woudn't be too
difficult to devise some connections [1] which would enable you to apply
mains pressure (4 bar or so) to each rad in turn. This is well within the
design spec of the rads - but higher than the running pressure of a
non-vented system - and will quickly show up any weak spots.

[1] e.g. http://tinyurl.com/2upouw + http://tinyurl.com/2qejqo +
http://tinyurl.com/2tlc87
--
Cheers,
Roger
______
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monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

In an earlier contribution to this discussion,
tvmo wrote:

Thanks for the reply.

So in a nutshell:

1. I can replace the boiler for a modern one without changing the
pipework [1]
2. I can replace the radiators for modern ones without changing the
pipework [1]
3. I can have the cylinder in the attic as long as the water cistern
is above it and the supporting structure is adequate

That's about it. But you may not *need* to change either - you can increase
the efficiency quite a lot just by updating the controls.

Is a system where you can heat up particular zones quite easy (and
affordable) to achieve, e.g. where you can heat up the downstairs
during the day, whereas the upstairs remains cool?


Zoning is easy (and relatively cheap) to achieve in *principle* - simply by
adding motorised zone valves, each controlled by a timer/thermostat - and
tied together to operate the boiler and pump whenever one or more zones are
demanding heat.

In practice, the ease or otherwise depends on how the system is currently
configured. If there are already separate upstairs and downstairs circuits,
it's dead easy. If (as often happens when the downstairs floors are solid)
there is only one circuit running between the floors, with pipes going up to
the upstairs rads and down to the downstairs rads (like my house!) it's much
more difficult to achieve zoning. The only realistic choice then is between
no zoning, and one zone per *room* - which gets pretty messy and expensive.
--
Cheers,
Roger
______
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monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

That's brilliant, thanks very much for the advice.

Now the hard bit, does anyone know a good plumber in the Bridgend
area, South Wales?!?!!!!!

"Owain" wrote in message
...
tvmo wrote:
1. I can replace the boiler for a modern one without changing the
pipework [1]
[1] This is on the provision that the pipework is pressure tested and
found to be sound

And that the existing pipework has sufficient controls eg radiator valves
to meet Part L of the building regs.

Rad valves only in the sleeping areas to meet Part L.

Thanks guys.

Any advice on what brand/type of boiler I should go for?

Is there any type of radiator that is better than another, i.e. high-
efficiency, low ongoing costs?

I've got 13 rooms in the house, can anyone give me a rough estimation
on how much this is likely to cost?

Any advice on how to get the best price and advice out of a plumber?

Cheers

tvmo wrote:
Thanks guys.

Any advice on what brand/type of boiler I should go for?


Not from me ..gas? oil? nucleasr fission :-)?
Is there any type of radiator that is better than another, i.e. high-
efficiency, low ongoing costs?

No. All the heat that goes in comes out. Soemwhere. That's the odd
things about radiators. All one can say is that of your CH pipes go
OUTSIDE teh insulation - i.e. through a cold roof - the bigger teh
radiator the lower the tempearture they need to run at and the less
losses you will get.

If your boiler works better at low temperatures alos, thenuse larger
rads also.

I've got 13 rooms in the house, can anyone give me a rough estimation
on how much this is likely to cost?

A fair bit. Id say between 5 and 7k but thats a guess only.

Any advice on how to get the best price and advice out of a plumber?

Ignore the advice, and get him to sign a written contract. ;-)




Cheers

In an earlier contribution to this discussion,
tvmo wrote:

Thanks guys.

Any advice on what brand/type of boiler I should go for?

Is there any type of radiator that is better than another, i.e. high-
efficiency, low ongoing costs?

I've got 13 rooms in the house, can anyone give me a rough estimation
on how much this is likely to cost?

Any advice on how to get the best price and advice out of a plumber?

Cheers

Can we just recap a little? What is your rationale for convincing yourself
that you need to spend *anything*? How old is the existing boiler? Is it
reliable? Can spare parts be obtained when necessary?

Is there anything wrong with the existing radiators? Are they adequate? [In
other words, have you calculated the heat losses for each room, and compared
them with the rated outputs of the relevant radiators?]

Why employ a plumber - this is a D-I-Y ng!? If you want to employ someone to
do whatever needs doing, at least educate yourself sufficiently to be able
to do it yourself - then you can discuss things on equal terms and not be
confounded with BS.
--
Cheers,
Roger
______
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monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

The boiler is at least 24 years old. Not sure if it reliable (I
haven't moved in yet), but I know it is very expensive to run. Parts
are not available, I've tried.

"Is there anything wrong with the existing radiators?" - I don't know
I haven't moved in yet
"Are they adequate? [In other words, have you calculated the heat
losses for each room, and compared them with the rated outputs of the
relevant radiators?]" - I don't know I haven't moved in yet, plus I
wouldn't have a clue on what to do anyway

"Why employ a plumber - this is a D-I-Y ng!?" - Is changing a boiler a
DIY-thing, I wouldn't have thought so? Good idea if you have enough
time as well.

"If you want to employ someone to do whatever needs doing, at least
educate yourself sufficiently to be able to do it yourself - then you
can discuss things on equal terms and not be confounded with BS" - why
do you think I've subscribed to this group? I'm open to suggestions,
are there any good books about installing a central heating system?

Thanks

In an earlier contribution to this discussion,
tvmo wrote:


"If you want to employ someone to do whatever needs doing, at least
educate yourself sufficiently to be able to do it yourself - then you
can discuss things on equal terms and not be confounded with BS"

- why do you think I've subscribed to this group?

Fair comment!

I'm open to suggestions,
are there any good books about installing a central heating system?


Have you looked at the FAQs suggested by Ed the other day? They are a good
starting place - namely:

The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
--
Cheers,
Roger
______
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monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

I did look over the articles but, and I may be being a bit thick here,
I didn't see the practical issues discussed re installing a complete
central heating system. Bar the pipework (hopefully!), that is the
task I will be undertaking.

Thanks.

On Fri, 28 Mar 2008 10:34:09 -0700, tvmo wrote:

I did look over the articles but, and I may be being a bit thick here, I
didn't see the practical issues discussed re installing a complete
central heating system. Bar the pipework (hopefully!), that is the task
I will be undertaking.

Thanks.

The boiler choice FAQ is specifically written to answer some of the
questions you are raising.

The wiki.diyfaq.org.uk has a few pages such as
http://wiki.diyfaq.org.uk/index.php?...Heating_Design



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

Are sealed systems better than open systems?

On 2008-04-01 12:52:39 +0100, tvmo said:

Are sealed systems better than open systems?

Yes.

In an earlier contribution to this discussion,
tvmo wrote:

Are sealed systems better than open systems?


Better at what? Are apples better than bananas?

Sealed and vented systems each have pros and cons.
--
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!

On Tue, 1 Apr 2008 04:52:39 -0700 (PDT) someone who may be tvmo
wrote this:-

Are sealed systems better than open systems?

It depends.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

tvmo wrote:

Are sealed systems better than open systems?

In most cases yes. See Ed'd sealed system FAQ for a list of reasons why.

--
Cheers,

John.

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\================================================= ================/

Thanks for the replies.

Roger: you seem a little uptight. It was a general question aimed at
getting personal experiences and knowledge. If you have nothing
further to contribute, don't.

Cheers

In an earlier contribution to this discussion,
tvmo wrote:

Thanks for the replies.

Roger: you seem a little uptight. It was a general question aimed at
getting personal experiences and knowledge. If you have nothing
further to contribute, don't.

Cheers

I was simply making the point (as have others) that, like a lot of things in
life, there isn't a simple yes or no answer - and a lot depends on the
criteria you are using to make an assessment. I hope I'm not uptight!
--
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!

On Tue, 1 Apr 2008 06:42:04 -0700 (PDT) someone who may be tvmo
wrote this:-

Roger: you seem a little uptight.

Yawn.

It was a general question aimed at
getting personal experiences and knowledge.

And in response Roger asked you a very sensible question. A question
which I note you have failed to answer so far.

Were you to answer that question you would probably get some more
information, though given the aggressive attitude perhaps not now.

Getting answers to general questions is what search engines are for.
Having used those one can ask more specific questions.

If you have nothing further to contribute, don't.

Yawn.

Roger has almost certainly got plenty more to contribute to the
group, unlike some.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Tue, 01 Apr 2008 14:02:26 +0100, Roger Mills wrote:

In an earlier contribution to this discussion, tvmo
wrote:

Are sealed systems better than open systems?


Better at what? Are apples better than bananas?

Sealed and vented systems each have pros and cons.

In domestic systems I'd have to say that sealed is almost always better.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

On Tue, 01 Apr 2008 14:10:31 +0100, David Hansen wrote:

On Tue, 1 Apr 2008 04:52:39 -0700 (PDT) someone who may be tvmo
wrote this:-

Are sealed systems better than open systems?

It depends.

To a certain extent. There are only a few reasons I can think of a

1) The existing system is correctly working and setup correctly and the
new boiler would require additional expenditure to add the sealed
components.

2) The existing system has radiators which are so old the designs can't
take the pressure.

3) The existing system has massive 'period' radiators which have such a
huge volume of primary water that a seal system would be impractical.
In this case I'd recommend that the technology levels are so different
that the new boiler is coupled to the old radiators via a heat exchanger
and athe primary is pressurized whilst the secondary circuit is open
vented.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

"Ed Sirett" wrote in message
...
On Tue, 01 Apr 2008 14:10:31 +0100, David Hansen wrote:

On Tue, 1 Apr 2008 04:52:39 -0700 (PDT) someone who may be tvmo
wrote this:-

Are sealed systems better than open systems?

It depends.

To a certain extent. There are only a few reasons I can think of a

1) The existing system is correctly working and setup correctly and the
new boiler would require additional expenditure to add the sealed
components.

2) The existing system has radiators which are so old the designs can't
take the pressure.

3) The existing system has massive 'period' radiators which have such a
huge volume of primary water that a seal system would be impractical.
In this case I'd recommend that the technology levels are so different
that the new boiler is coupled to the old radiators via a heat exchanger
and athe primary is pressurized whilst the secondary circuit is open
vented.

The problem with sealed system is that the filling loops are left
permanently connected by installers - not supposed to be. Some are a part
of the boiler too. When the expansion vessel deflates, or a leak, the user
just tops it up by turning the tap. This leads to water gushing out of the
discharge pipe, sometime onto public walkways. And the users will do this
for months and years, especially those in rented property. It also
introduces fresh water into the system and accelerates corrosion. Sealed
system expansion vessels fail eventually - usually sooner than later. Sealed
systems are intolerable of minute leaks too. I know of some systems where a
small leak was never found after extensive searching. The pressure
eventually drops and a service call.

A one pipe system with a close fitting lid F&E tank is generally the better
option in reality. Sealed systems are great when installed properly and
don't go wrong. The expansion vessel prevents pump cavitation too and
quietens pump operation too.

Doctor Drivel wrote:

The problem with sealed system is that the filling loops are left
permanently connected by installers - not supposed to be. Some are a

That is not a problem with sealed systems. It might be a problem with
some installers.

part of the boiler too. When the expansion vessel deflates, or a leak,
the user just tops it up by turning the tap. This leads to water gushing
out of the discharge pipe, sometime onto public walkways. And the users

Clueless people can cause problems with any installation. They are just
as likely to leave a header tank system pumping over for years.

corrosion. Sealed system expansion vessels fail eventually - usually
sooner than later.

Plenty of people seem to mange for twenty years or more without any
problem...

Sealed systems are intolerable of minute leaks too.

Which is another advantage of the sealed system.

I know of some systems where a small leak was never found after
extensive searching. The pressure eventually drops and a service call.

I know of a vented system where a small leak was never found until
several years later when a substantial dry infestation was discovered. I
know which I would rather have.

A one pipe system with a close fitting lid F&E tank is generally the
better option in reality.

For some versions of reality perhaps...

Sealed systems are great when installed
properly and don't go wrong. The expansion vessel prevents pump
cavitation too and quietens pump operation too.

Plus no problems with air locks, or difficulties refilling the system etc.


--
Cheers,

John.

/================================================== ===============\
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|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In an earlier contribution to this discussion,
Ed Sirett wrote:

On Tue, 01 Apr 2008 14:02:26 +0100, Roger Mills wrote:

In an earlier contribution to this discussion, tvmo
wrote:

Are sealed systems better than open systems?


Better at what? Are apples better than bananas?

Sealed and vented systems each have pros and cons.

In domestic systems I'd have to say that sealed is almost always
better.

I would have to agree that sealed systems provide a better techical solution
in preventing pumping over and air locks - but there is rather more to go
wrong. They are less tolerant of slight leaks, and failure of the expansion
vessel causes a whole raft of problems.

It would be interesting (but I ain't going to do it! g) to see an analysis
of all the posts here which report problems with CH systems, and showing
what proportion are sealed vs vented.
--
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!

"John Rumm" wrote in message
news:9L2dnU7DtO8yE27anZ2dneKdnZydnZ2d@plusnet...
Doctor Drivel wrote:

The problem with sealed system is that the filling loops are left
permanently connected by installers - not supposed to be. Some are a

That is not a problem with sealed systems. It might be a problem with some
installers.

It is a big prblems with sealed system.

part of the boiler too. When the expansion vessel deflates, or a leak,
the user just tops it up by turning the tap. This leads to water gushing
out of the discharge pipe, sometime onto public walkways. And the users

Clueless people can cause problems with any installation.

A sealed systems happen to be one in big way.

They are just as likely to leave a header tank system pumping over for
years.

Very rare.

corrosion. Sealed system expansion vessels fail eventually - usually
sooner than later.

Plenty of people seem to mange for twenty years or more without any
problem...

Most do not.

snip drivel

Doctor Drivel wrote:

Doctor Drivel wrote:

The problem with sealed system is that the filling loops are left
permanently connected by installers - not supposed to be. Some are a

That is not a problem with sealed systems. It might be a problem with
some installers.

It is a big prblems with sealed system.

The system works perfectly with the filling loop connected. Its only if
some muppet starts filling it to mask some other problem that it is an
issue. That's not a problem with sealed systems. In the same way that
someone setting the pump speed too high on a vented system and causing
pump over is not an inherent problem with the vented system, but a
problem with its installation.

part of the boiler too. When the expansion vessel deflates, or a
leak, the user just tops it up by turning the tap. This leads to
water gushing out of the discharge pipe, sometime onto public
walkways. And the users

Clueless people can cause problems with any installation.

A sealed systems happen to be one in big way.

Again in English?

They are just as likely to leave a header tank system pumping over for
years.

Very rare.

So someone that is clueless enough to not spot water pouring out of the
PRV every time the system gets hot, and topping up twice a day is
however going to correctly identify, diagnose and rectify a pumping over
problem?

If you believe that you are barking.

corrosion. Sealed system expansion vessels fail eventually - usually
sooner than later.

Plenty of people seem to mange for twenty years or more without any
problem...

Most do not.

Most systems work fine most of the time. Its only a small proportion of
systems of any type that go wrong, so you comment (as usual) make little
sense.


--
Cheers,

John.

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Whether I was aggresive or not (apologies if I was) or Roger's comment
about apples/bananas were flippant/uptight or not (sorry if I read it
wrong), the thread seems to continue.

David Hansen: I won't labour on your points....yawn.

I read with interest the different point of views and I'm learning
lots that you don't pick up by just reading articles.

Thanks all.

tvmo wrote:

Whether I was aggresive or not (apologies if I was) or Roger's comment
about apples/bananas were flippant/uptight or not (sorry if I read it
wrong), the thread seems to continue.

Don't think you were aggressive - there are worse culprits here! ;-)

Roger can be relied on to give considered and useful advice, I think you
may have just read it the wrong way.

I read with interest the different point of views and I'm learning
lots that you don't pick up by just reading articles.

Yup, much to be said for a bit of disagreement since it can take the
thread into new and interesting areas that otherwise would remain
uncharted.


--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
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"John Rumm" wrote in message
news:1oSdncBDHeMGs2nanZ2dnUVZ8vydnZ2d@plusnet...
Doctor Drivel wrote:

Doctor Drivel wrote:

The problem with sealed system is that the filling loops are left
permanently connected by installers - not supposed to be. Some are a

That is not a problem with sealed systems. It might be a problem with
some installers.

It is a big prblems with sealed system.

The system works perfectly with the filling loop connected.

If the check valve fails it spurts contaminated water into the drinking
water mains.

Its only if some muppet starts filling it to mask some other problem that
it is an issue.

Which is common.

That's not a problem with sealed systems.

It is, if the system were not sealed and configured as they are it would not
happen.

In the same way that someone setting the pump speed too high on a vented
system and causing pump over is not an inherent problem with the vented
system, but a problem with its installation.

A rare problem.

Doctor Drivel wrote:

The system works perfectly with the filling loop connected.

If the check valve fails it spurts contaminated water into the drinking
water mains.

if... if... if...

if the tap is also left open, and the mains also suffers a drop in
pressure so that it is lower than that stored in the system.

Tap off, double check valve in place, loop connected. Common occurrence,
no risk to system or water main.

Its only if some muppet starts filling it to mask some other problem
that it is an issue.

Which is common.

That's not a problem with sealed systems.

It is, if the system were not sealed and configured as they are it would
not happen.

you're repeating yourself dribble...

In the same way that someone setting the pump speed too high on a
vented system and causing pump over is not an inherent problem with
the vented system, but a problem with its installation.

A rare problem.

lol!



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
news:ifWdnRIoz5c962vanZ2dneKdnZydnZ2d@plusnet...
Doctor Drivel wrote:

The system works perfectly with the filling loop connected.

If the check valve fails it spurts contaminated water into the drinking
water mains.

if... if... if...

Yes, if. Murphy's law says.....

It is, if the system were not sealed and configured as they are it would
not happen.

you're repeating yourself dribble...

It is, if the system were not sealed and configured as they are it would not
happen.

You know sweet FA about heating systems in the real world.