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Frank W
 
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Default Automatic water pressure maintainer for combi boiler system?

On Tue, 19 Aug 2003 21:20:15 +0100, "IMM" wrote:


What do you mean?


Well, on my own combi-fed central heating system, I have to keep
checking the pressure occasionally by looking at a dial on the front
of the combi. Every time the pressure drops below the recommended
minimum, you have to manually top up the pressure using a removeable
link to the mains water supply. What I'm thinking of is a device that
will keep doing that for you whenever the pressure drops (say due to
small leakage at pipe joins or whatever). My own system often needs
its pressure topping up manually.

Frank
  #2   Report Post  
IMM
 
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Default Automatic water pressure maintainer for combi boiler system?


"Frank W" wrote in message
...
On Tue, 19 Aug 2003 21:20:15 +0100, "IMM" wrote:


What do you mean?


Well, on my own combi-fed central heating system, I have to keep
checking the pressure occasionally by looking at a dial on the front
of the combi. Every time the pressure drops below the recommended
minimum, you have to manually top up the pressure using a removeable
link to the mains water supply. What I'm thinking of is a device that
will keep doing that for you whenever the pressure drops (say due to
small leakage at pipe joins or whatever). My own system often needs
its pressure topping up manually.


It has to be topped up manually. If it keeps dropping you have a problem,
such as: water leak, the pressure in the pressure vessel needs topping up,
the diaphragm in the pressure vessel is holed, hole in the plate
heat-exchanger, etc.


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  #3   Report Post  
Frank W
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

On Wed, 20 Aug 2003 08:29:05 +0100, Andy Hall
wrote:

On Wed, 20 Aug 2003 06:02:15 GMT, (Frank W) wrote:

On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.

Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.


This would be really difficult to find, especially if it's a smallish
system, because the amount of water involved is small.



There are such things, but they are relatively expensive for what they
are in order to comply with water regulations.

Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...

Thanks...

Frank


I remember seeing these illustrated on one of the large plumbing
suppliers and/or manufacturer's sites a few months ago. I'm thinking
that it was BES or RWC but can't see them on either - possibly they
have stopped them. I'll look again a bit later.

At any rate, they consisted of a small open tank rather like on an
open vented system, a pump to produce the pressure, a non return valve
and a pressure sensor switch. I seem to remember them costing in the
hundreds of pounds which seemed outrageous for what they were. I
would have thought that they were more intended for commercial systems
of much greater capacity, where for similar reasons to your situation,
you don't want people dinking with the system.

Take a look at Ed Sirett's Sealed System FAQ for some ideas because
this should be fixable.

One thing to look at is whether the non-return valve is allowing a
tiny amount of backflow. Try disconnecting the filling loop (which
you are supposed to do anyway) and see if there is any sign of
seepage.

Another thing that you could try for this level of leakage is a leak
sealer treatment which is introduced into the system via a radiator.
Reports of this approach in situations such as yours have been good.


Andy - That's all very helpful advice; thank you! I will certainly
follow your suggestions.

BTW, re the water-pressure maintaining device... seems like a good
project for an inventor with plumbing knowledge. I suspect there may
be an alternative solution to the one you saw with the header tank and
electric pump. If anyone knows of one - or invents one, that is cheap
and effective, please post a description of it here...

Frank

  #4   Report Post  
BillR
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

Frank W wrote:
Is thee such a thing as an automatic water pressure maintainer for a
combi-boiler-poweed HWCH system?

It seems to me that such a device would be perfectly feasable - but
does anyone sell them? If so, who, and how much?

Thanks
Frank


Very bad idea. If you've got a leak it should be fixed
1) you don't know where the water is going and rotting it may cause.
2) constantly changing the water in the sealed system will hasten its demise
due to corrosion.

Small leaks that cause you to top your system say once a month can be cured
with the Fernox stuff in a standard cartridge that can be injected into
radiator bleed valve. Has worked 100% for me on 2 different systems.
Mind you its not cheap RRP £20 I found mine on special offer at a plumbers
merchant.


  #5   Report Post  
IMM
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?


"Frank W" wrote in message
...
On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.


Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.

There are such things, but they are relatively expensive for what they
are in order to comply with water regulations.


Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...


If you rent it out you need a CORGI landlords certificate. He will fail the
combi. Get it fixed.


---
--

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  #6   Report Post  
IMM
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?


"Frank W" wrote in message
...
On Wed, 20 Aug 2003 08:29:05 +0100, Andy Hall
wrote:

On Wed, 20 Aug 2003 06:02:15 GMT, (Frank W) wrote:

On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.

Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.

This would be really difficult to find, especially if it's a smallish
system, because the amount of water involved is small.



There are such things, but they are relatively expensive for what

they
are in order to comply with water regulations.

Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...

Thanks...

Frank

I remember seeing these illustrated on one of the large plumbing
suppliers and/or manufacturer's sites a few months ago. I'm thinking
that it was BES or RWC but can't see them on either - possibly they
have stopped them. I'll look again a bit later.

At any rate, they consisted of a small open tank rather like on an
open vented system, a pump to produce the pressure, a non return valve
and a pressure sensor switch. I seem to remember them costing in the
hundreds of pounds which seemed outrageous for what they were. I
would have thought that they were more intended for commercial systems
of much greater capacity, where for similar reasons to your situation,
you don't want people dinking with the system.

Take a look at Ed Sirett's Sealed System FAQ for some ideas because
this should be fixable.

One thing to look at is whether the non-return valve is allowing a
tiny amount of backflow. Try disconnecting the filling loop (which
you are supposed to do anyway) and see if there is any sign of
seepage.

Another thing that you could try for this level of leakage is a leak
sealer treatment which is introduced into the system via a radiator.
Reports of this approach in situations such as yours have been good.


Andy - That's all very helpful advice; thank you! I will certainly
follow your suggestions.

BTW, re the water-pressure maintaining device... seems like a good
project for an inventor with plumbing knowledge. I suspect there may
be an alternative solution to the one you saw with the header tank and
electric pump. If anyone knows of one - or invents one, that is cheap
and effective, please post a description of it here...


The system IS NOT supposed to be permanently connected to the mains.


---
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http://www.grisoft.com).
Version: 6.0.507 / Virus Database: 304 - Release Date: 04/08/2003


  #7   Report Post  
Frank W
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

On Wed, 20 Aug 2003 11:33:03 +0100, "IMM" wrote:


"Frank W" wrote in message
...
On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.

Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.

There are such things, but they are relatively expensive for what they
are in order to comply with water regulations.

Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...


If you rent it out you need a CORGI landlords certificate. He will fail the
combi. Get it fixed.


I wasn't aware of that. Thanks for pointing it out.

Frank
  #8   Report Post  
James Salisbury
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?


BTW, re the water-pressure maintaining device... seems like a good
project for an inventor with plumbing knowledge. I suspect there may
be an alternative solution to the one you saw with the header tank and
electric pump. If anyone knows of one - or invents one, that is cheap
and effective, please post a description of it here...


NEVER disclose a new idea here or elsewhere in public before the patent is
filled or you will lose all patent rights!!!!!!!!!!


  #9   Report Post  
I.Wilson
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

I recently did some work to my system (replaced two radiators, and one
TRV). I too suffer from regular topping up. I suspect this is from
small leaks at the BSP tails and/or the pipe/valve joints. If the
leaks are small enough then the water evaporates from the heat before
you notice it.

Anyway, the interesting thing I found was that the system holds approx
50 litres of water, yet it only takes loss of 1 litre to cause the
pressure gauge to drop from 1 to almost zero (on a 7 rad system with a
really old Valliant combi).

I used to get concerned when the gauge dropped this low, but not
anymore.

If you have a leaking BSP tail / rad joint then it can be re-taped
(PTFE) without draining the system. Just shut off the rad valves, and
put a towel down to catch the leakage. Use a BSP plug to cap off the
rad while you are re-doing the PTFE tape. I did this last week for
two new radiators, and only lost 0.5 litres per radiator.

Ian

Andy Hall wrote in message . ..
On Wed, 20 Aug 2003 06:02:15 GMT, (Frank W) wrote:

On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.


Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.


This would be really difficult to find, especially if it's a smallish
system, because the amount of water involved is small.



There are such things, but they are relatively expensive for what they
are in order to comply with water regulations.


Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...

Thanks...

Frank


I remember seeing these illustrated on one of the large plumbing
suppliers and/or manufacturer's sites a few months ago. I'm thinking
that it was BES or RWC but can't see them on either - possibly they
have stopped them. I'll look again a bit later.

At any rate, they consisted of a small open tank rather like on an
open vented system, a pump to produce the pressure, a non return valve
and a pressure sensor switch. I seem to remember them costing in the
hundreds of pounds which seemed outrageous for what they were. I
would have thought that they were more intended for commercial systems
of much greater capacity, where for similar reasons to your situation,
you don't want people dinking with the system.

Take a look at Ed Sirett's Sealed System FAQ for some ideas because
this should be fixable.

One thing to look at is whether the non-return valve is allowing a
tiny amount of backflow. Try disconnecting the filling loop (which
you are supposed to do anyway) and see if there is any sign of
seepage.

Another thing that you could try for this level of leakage is a leak
sealer treatment which is introduced into the system via a radiator.
Reports of this approach in situations such as yours have been good.





.andy

To email, substitute .nospam with .gl

  #11   Report Post  
Ed Sirett
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

BillR wrote:
=


Frank W wrote:
Is thee such a thing as an automatic water pressure maintainer for a
combi-boiler-poweed HWCH system?

It seems to me that such a device would be perfectly feasable - but
does anyone sell them? If so, who, and how much?

Thanks
Frank

=


Very bad idea. If you've got a leak it should be fixed
1) you don't know where the water is going and rotting it may cause.
2) constantly changing the water in the sealed system will hasten its d=

emise
due to corrosion.
=


Small leaks that cause you to top your system say once a month can be c=

ured
with the Fernox stuff in a standard cartridge that can be injected into=


radiator bleed valve. Has worked 100% for me on 2 different systems.
Mind you its not cheap RRP =A320 I found mine on special offer at a pl=

umbers
merchant.


It does depend on how often he is topping up. It might be going a couple
of months between top ups but the OP really hates doing the job. ON the
other hand there may be a big leak (or other problem) whcih needs fixing
pronto.

-- =

Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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
  #12   Report Post  
Ed Sirett
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

IMM wrote:

"Frank W" wrote in message
...
On Wed, 20 Aug 2003 08:29:05 +0100, Andy Hall
wrote:

On Wed, 20 Aug 2003 06:02:15 GMT, (Frank W) wrote:

On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.

Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.

This would be really difficult to find, especially if it's a smallish
system, because the amount of water involved is small.



There are such things, but they are relatively expensive for what

they
are in order to comply with water regulations.

Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...

Thanks...

Frank

I remember seeing these illustrated on one of the large plumbing
suppliers and/or manufacturer's sites a few months ago. I'm thinking
that it was BES or RWC but can't see them on either - possibly they
have stopped them. I'll look again a bit later.

At any rate, they consisted of a small open tank rather like on an
open vented system, a pump to produce the pressure, a non return valve
and a pressure sensor switch. I seem to remember them costing in the
hundreds of pounds which seemed outrageous for what they were. I
would have thought that they were more intended for commercial systems
of much greater capacity, where for similar reasons to your situation,
you don't want people dinking with the system.

Take a look at Ed Sirett's Sealed System FAQ for some ideas because
this should be fixable.

One thing to look at is whether the non-return valve is allowing a
tiny amount of backflow. Try disconnecting the filling loop (which
you are supposed to do anyway) and see if there is any sign of
seepage.

Another thing that you could try for this level of leakage is a leak
sealer treatment which is introduced into the system via a radiator.
Reports of this approach in situations such as yours have been good.


Andy - That's all very helpful advice; thank you! I will certainly
follow your suggestions.

BTW, re the water-pressure maintaining device... seems like a good
project for an inventor with plumbing knowledge. I suspect there may
be an alternative solution to the one you saw with the header tank and
electric pump. If anyone knows of one - or invents one, that is cheap
and effective, please post a description of it here...


A simple implementation (which would fall foul of several bylaws) would
be a pressure reducing valve, set to 1 Bar output and then a filling
loop permanently connected and opened to the heating circuit.
This would ensure the circuit never fell more than a small amount below
the 1 bar from the reducing valve.
When the system is hot the NRVs in the filling loop will keep it in.

Unfortunately a failure mode of PRVs is to let full pressure through,
which would be a bad thing.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at
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
  #13   Report Post  
Ed Sirett
 
Posts: n/a
Default Automatic water pressure maintainer for combi boiler system?

"I.Wilson" wrote:

I recently did some work to my system (replaced two radiators, and one
TRV). I too suffer from regular topping up. I suspect this is from
small leaks at the BSP tails and/or the pipe/valve joints. If the
leaks are small enough then the water evaporates from the heat before
you notice it.

Anyway, the interesting thing I found was that the system holds approx
50 litres of water, yet it only takes loss of 1 litre to cause the
pressure gauge to drop from 1 to almost zero (on a 7 rad system with a
really old Valliant combi).

I used to get concerned when the gauge dropped this low, but not
anymore.

If you have a leaking BSP tail / rad joint then it can be re-taped
(PTFE) without draining the system. Just shut off the rad valves, and
put a towel down to catch the leakage. Use a BSP plug to cap off the
rad while you are re-doing the PTFE tape. I did this last week for
two new radiators, and only lost 0.5 litres per radiator.

Ian

Andy Hall wrote in message . ..
On Wed, 20 Aug 2003 06:02:15 GMT, (Frank W) wrote:

On Tue, 19 Aug 2003 21:51:50 +0100, Andy Hall
wrote:



It would be a good idea to find out and fix why the pressure is
dropping. If this is an ongoing occurence, you may have a leak
producing enough moisture to set up the conditions for rotting of the
timbers of the house, and that can be very expensive to fix.

Andy, It currently needs topping up about once a month whan the system
is in use. Is that excessive? I cannot find any leaks in the plumbing,
but I haven't taken the floorboards up to check hitten pipe joints.


This would be really difficult to find, especially if it's a smallish
system, because the amount of water involved is small.



There are such things, but they are relatively expensive for what they
are in order to comply with water regulations.

Any idea how expensive? Would it be possible to something up using a
one-way valve and some sort of pressure operated valve?

The reason I'm interested in this idea is because I want to rent my
house out and go away for a long period. I don't want to have to rely
on the tenants to keep the pressure adjusted... Chances are they'd
just not bother - or forget...

Thanks...

Frank


I remember seeing these illustrated on one of the large plumbing
suppliers and/or manufacturer's sites a few months ago. I'm thinking
that it was BES or RWC but can't see them on either - possibly they
have stopped them. I'll look again a bit later.

At any rate, they consisted of a small open tank rather like on an
open vented system, a pump to produce the pressure, a non return valve
and a pressure sensor switch. I seem to remember them costing in the
hundreds of pounds which seemed outrageous for what they were. I
would have thought that they were more intended for commercial systems
of much greater capacity, where for similar reasons to your situation,
you don't want people dinking with the system.

Take a look at Ed Sirett's Sealed System FAQ for some ideas because
this should be fixable.

One thing to look at is whether the non-return valve is allowing a
tiny amount of backflow. Try disconnecting the filling loop (which
you are supposed to do anyway) and see if there is any sign of
seepage.

Another thing that you could try for this level of leakage is a leak
sealer treatment which is introduced into the system via a radiator.
Reports of this approach in situations such as yours have been good.


Replying to top posted reply :-(.

Check the operation of the expansion vessel and/or drop its pre-charge
pressure to about 0.6 bar.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at
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
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