Inside my boiler is a Grundfos switch with a dial for numbers 1/2/3.
the boiler works fine when this is on 1 but if i switch it to 2 or 3
(which i assume will make the water hotter) the boiler will not turn
off if i run the central heating. it just constantly stays on
burning. However if i turn off the downstairs radiators it goes back
to it's stop-start usual self. The problem also is that the water
does not get any warmer with the switch at 2 or 3.

Does this dial control the water temperature? or any clues as to how i
would sort it out... many thanks guys

On Thu, 12 Feb 2004 04:45:41 +0000, Shabs wrote:

Inside my boiler is a Grundfos switch with a dial for numbers 1/2/3.
the boiler works fine when this is on 1 but if i switch it to 2 or 3
(which i assume will make the water hotter) the boiler will not turn
off if i run the central heating. it just constantly stays on
burning. However if i turn off the downstairs radiators it goes back
to it's stop-start usual self. The problem also is that the water
does not get any warmer with the switch at 2 or 3.

Does this dial control the water temperature? or any clues as to how i
would sort it out... many thanks guys

Almost always you set a combi boiler's internal pump to 3 (unless the
instruction say otherwise). Sometimes the instructions say that you may
turn it down but will have reduced water heating performance - which on
most installations would not be welcome.

This setting is how hard the the pump works.

To make the radiators hotter try the knob on the outside of the boiler!


--
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

OK I agree that the pump should be set to 3, but if i move the switch
into position 3 I can hear a sort of different noise, but when I start
the central heating from position 3, the boiler does not turn off,
just runs continuous and the pressure goes sky high. With the pump on
no. 1 the boiler does the stop-start stuff. How would i get the pump
onto no.3 but the boiler doing the usual stop-start routine.

On Fri, 13 Feb 2004 01:13:27 +0000, Shabs wrote:

OK I agree that the pump should be set to 3, but if i move the switch
into position 3 I can hear a sort of different noise, but when I start
the central heating from position 3, the boiler does not turn off,
just runs continuous and the pressure goes sky high. With the pump on
no. 1 the boiler does the stop-start stuff. How would i get the pump
onto no.3 but the boiler doing the usual stop-start routine.

It is very unlikely that setting the pump to the high setting will by
itself cause any problem.
You should now procede to tackle the cause of the high pressure directly.
See the Sealed system FAQ it is likely that as the _average_ water
temperature rises the system pressure is rising too quickly.
The cause for this is likely a failed expansion vessel.

The boiler will likely operate correctly once the water temperature has
stabilised but this may mean the prsssure will go even higher and water is
thrown out of the vent pipe.


--
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

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from going
over 3 bar by limiting the temp to 75C and keeping min pressure at about 0.4
bar.

I presume that the air will have leaked and needs pumping rather than the
diaphram holed - or am I just being hopeful!!

John


"Ed Sirett" wrote in message
news
On Fri, 13 Feb 2004 01:13:27 +0000, Shabs wrote:

OK I agree that the pump should be set to 3, but if i move the switch
into position 3 I can hear a sort of different noise, but when I start
the central heating from position 3, the boiler does not turn off,
just runs continuous and the pressure goes sky high. With the pump on
no. 1 the boiler does the stop-start stuff. How would i get the pump
onto no.3 but the boiler doing the usual stop-start routine.

It is very unlikely that setting the pump to the high setting will by
itself cause any problem.
You should now procede to tackle the cause of the high pressure directly.
See the Sealed system FAQ it is likely that as the _average_ water
temperature rises the system pressure is rising too quickly.
The cause for this is likely a failed expansion vessel.

The boiler will likely operate correctly once the water temperature has
stabilised but this may mean the prsssure will go even higher and water is
thrown out of the vent pipe.


--
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

On Sat, 14 Feb 2004 18:22:06 -0000, "JohnB"
wrote:

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from going
over 3 bar by limiting the temp to 75C and keeping min pressure at about 0.4
bar.

I presume that the air will have leaked and needs pumping rather than the
diaphram holed - or am I just being hopeful!!

John



Try turning off the heating and remove the dust cap from the Schrader
valve on the expansion vessel. Release the pressure carefully as you
would to let a car tyre down.

If water comes out then you know the answer to your question and a new
vessel is needed. Otherwise, release the water pressure on the heating
circuit completely and then precharge the expansion vessel with a
suitable supply of compressed air or a tyre inflator. Finally
pressurise the water side again.

If you do have to replace the vessel, they come precharged with
nitrogen


..andy

To email, substitute .nospam with .gl

Thanks.

This is going to be interesting! Hopefully that will save me the cost of a
13 litre expansion tank. Costly no doubt.

John


"Andy Hall" wrote in message
...
On Sat, 14 Feb 2004 18:22:06 -0000, "JohnB"
wrote:

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from
going
over 3 bar by limiting the temp to 75C and keeping min pressure at about
0.4
bar.

I presume that the air will have leaked and needs pumping rather than
the
diaphram holed - or am I just being hopeful!!

John



Try turning off the heating and remove the dust cap from the Schrader
valve on the expansion vessel. Release the pressure carefully as you
would to let a car tyre down.

If water comes out then you know the answer to your question and a new
vessel is needed. Otherwise, release the water pressure on the heating
circuit completely and then precharge the expansion vessel with a
suitable supply of compressed air or a tyre inflator. Finally
pressurise the water side again.

If you do have to replace the vessel, they come precharged with
nitrogen


.andy

To email, substitute .nospam with .gl

On Sat, 14 Feb 2004 18:51:30 +0000, Andy Hall wrote:

On Sat, 14 Feb 2004 18:22:06 -0000, "JohnB"
wrote:

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from going
over 3 bar by limiting the temp to 75C and keeping min pressure at about 0.4
bar.

I presume that the air will have leaked and needs pumping rather than the
diaphram holed - or am I just being hopeful!!

John



Try turning off the heating and remove the dust cap from the Schrader
valve on the expansion vessel. Release the pressure carefully as you
would to let a car tyre down.

If water comes out then you know the answer to your question and a new
vessel is needed. Otherwise, release the water pressure on the heating
circuit completely and then precharge the expansion vessel with a
suitable supply of compressed air or a tyre inflator. Finally
pressurise the water side again.

If you do have to replace the vessel, they come precharged with
nitrogen
.... to around 6 bar so you'll have to let some out.

A work around would be to drain a radiator in a spare room (if you have
one), but don't bleed the radiator, the air in the radiator will act as a
good expansion vessel until you can replace/add the real one.


--
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

On Sat, 14 Feb 2004 21:54:52 -0000, "JohnB"
wrote:

Thanks.

This is going to be interesting! Hopefully that will save me the cost of a
13 litre expansion tank. Costly no doubt.

John


Is it integral in the boiler, or separate?

You can get separate ones of that size for about £15 so it's not too
horrendous.





"Andy Hall" wrote in message
.. .
On Sat, 14 Feb 2004 18:22:06 -0000, "JohnB"
wrote:

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from
going
over 3 bar by limiting the temp to 75C and keeping min pressure at about
0.4
bar.

I presume that the air will have leaked and needs pumping rather than
the
diaphram holed - or am I just being hopeful!!

John



Try turning off the heating and remove the dust cap from the Schrader
valve on the expansion vessel. Release the pressure carefully as you
would to let a car tyre down.

If water comes out then you know the answer to your question and a new
vessel is needed. Otherwise, release the water pressure on the heating
circuit completely and then precharge the expansion vessel with a
suitable supply of compressed air or a tyre inflator. Finally
pressurise the water side again.

If you do have to replace the vessel, they come precharged with
nitrogen


.andy

To email, substitute .nospam with .gl


..andy

To email, substitute .nospam with .gl

That is a brilliant idea!!

I may well make use of that as I am due to donate my prostate to the local
hospital in a weeks time & may not have time to replace it if necc.

John


"Ed Sirett" wrote in message
news
On Sat, 14 Feb 2004 18:51:30 +0000, Andy Hall wrote:

On Sat, 14 Feb 2004 18:22:06 -0000, "JohnB"
wrote:

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from
going
over 3 bar by limiting the temp to 75C and keeping min pressure at about
0.4
bar.

I presume that the air will have leaked and needs pumping rather than
the
diaphram holed - or am I just being hopeful!!

John



Try turning off the heating and remove the dust cap from the Schrader
valve on the expansion vessel. Release the pressure carefully as you
would to let a car tyre down.

If water comes out then you know the answer to your question and a new
vessel is needed. Otherwise, release the water pressure on the heating
circuit completely and then precharge the expansion vessel with a
suitable supply of compressed air or a tyre inflator. Finally
pressurise the water side again.

If you do have to replace the vessel, they come precharged with
nitrogen
... to around 6 bar so you'll have to let some out.

A work around would be to drain a radiator in a spare room (if you have
one), but don't bleed the radiator, the air in the radiator will act as a
good expansion vessel until you can replace/add the real one.


--
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

You amaze me. I am getting used to my boiler costing a fortune.

A dreaded Potterton Flowshure+ hence integral but (for once) easily
removable tank. Being Potterton it may be much more expensive than normal to
get the shape that fits. If so could be a good idea to fit an external one
for that price.

John

"Andy Hall" wrote in message
...
On Sat, 14 Feb 2004 21:54:52 -0000, "JohnB"
wrote:

Thanks.

This is going to be interesting! Hopefully that will save me the cost of
a
13 litre expansion tank. Costly no doubt.

John


Is it integral in the boiler, or separate?

You can get separate ones of that size for about £15 so it's not too
horrendous.





"Andy Hall" wrote in message
.. .
On Sat, 14 Feb 2004 18:22:06 -0000, "JohnB"
wrote:

Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from
going
over 3 bar by limiting the temp to 75C and keeping min pressure at
about
0.4
bar.

I presume that the air will have leaked and needs pumping rather than
the
diaphram holed - or am I just being hopeful!!

John



Try turning off the heating and remove the dust cap from the Schrader
valve on the expansion vessel. Release the pressure carefully as you
would to let a car tyre down.

If water comes out then you know the answer to your question and a new
vessel is needed. Otherwise, release the water pressure on the heating
circuit completely and then precharge the expansion vessel with a
suitable supply of compressed air or a tyre inflator. Finally
pressurise the water side again.

If you do have to replace the vessel, they come precharged with
nitrogen


.andy

To email, substitute .nospam with .gl


.andy

To email, substitute .nospam with .gl

On Sun, 15 Feb 2004 16:49:00 +0000, JohnB wrote:

You amaze me. I am getting used to my boiler costing a fortune.

A dreaded Potterton Flowshure+ hence integral but (for once) easily
removable tank. Being Potterton it may be much more expensive than normal to
get the shape that fits. If so could be a good idea to fit an external one
for that price.

[Please don't reply at the top. ]
If the one in the boiler is easily exchanged (they usually are very
inaccessible) then the manufacturers replacement is worth paying the extra
(probably double) over a generaic component that would have to be fitted
elsewhere.

--
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

"Ed Sirett" wrote in message
news
On Sun, 15 Feb 2004 16:49:00 +0000, JohnB wrote:

You amaze me. I am getting used to my boiler costing a fortune.

A dreaded Potterton Flowshure+ hence integral but (for once) easily
removable tank. Being Potterton it may be much more expensive than
normal to
get the shape that fits. If so could be a good idea to fit an external
one
for that price.

[Please don't reply at the top. ]
If the one in the boiler is easily exchanged (they usually are very
inaccessible) then the manufacturers replacement is worth paying the extra
(probably double) over a generaic component that would have to be fitted
elsewhere.

If you do replace it with a generic vessel, fit it on the return pipe.

I have just checked HRPC online (thanks for you commenting elsewhere that
they had an online site). £197 for the correct potterton retail 13.5L
expansion tank .....gasp ...... Even trade will be pricey. I see they have
Altecnic 18L at £39. The max working bar allowed is 4 so still should be
OK.

Looks as if they have to be fitted the correct way round. Would not have
thought of that.

Perhaps it would be cheaper in the long run to put a well lagged radiator in
the loft and keep it filled with air!!!

JohnB

"Ed Sirett" wrote in message
news
On Sun, 15 Feb 2004 16:49:00 +0000, JohnB wrote:

You amaze me. I am getting used to my boiler costing a fortune.

A dreaded Potterton Flowshure+ hence integral but (for once) easily
removable tank. Being Potterton it may be much more expensive than
normal to
get the shape that fits. If so could be a good idea to fit an external
one
for that price.

[Please don't reply at the top. ]
If the one in the boiler is easily exchanged (they usually are very
inaccessible) then the manufacturers replacement is worth paying the extra
(probably double) over a generaic component that would have to be fitted
elsewhere.

--
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

"john.bunting" wrote in message
...
I have just checked HRPC online (thanks for you commenting elsewhere that
they had an online site). £197 for the correct potterton retail
13.5L
expansion tank .....gasp ...... Even trade will be pricey. I see they have
Altecnic 18L at £39. The max working bar allowed is 4 so still should be
OK.

Looks as if they have to be fitted the correct way round. Would not have
thought of that.

Perhaps it would be cheaper in the long run to put a well lagged radiator
in
the loft and keep it filled with air!!!

Using a rad is temp solution. Use a proper pressure vessel.

On Sun, 15 Feb 2004 23:11:07 +0000, IMM wrote:


"john.bunting" wrote in message
...
I have just checked HRPC online (thanks for you commenting elsewhere that
they had an online site). £197 for the correct potterton retail
13.5L
expansion tank .....gasp ...... Even trade will be pricey. I see they have
Altecnic 18L at £39. The max working bar allowed is 4 so still should be
OK.

Looks as if they have to be fitted the correct way round. Would not have
thought of that.

Perhaps it would be cheaper in the long run to put a well lagged radiator
in
the loft and keep it filled with air!!!

Using a rad is temp solution. Use a proper pressure vessel.

Agreed, there are issues withthe air disolving into the water and coming
out elsewhere, if nothing else.


--
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

On Sun, 15 Feb 2004 22:29:38 +0000, IMM wrote:


"Ed Sirett" wrote in message
news
On Sun, 15 Feb 2004 16:49:00 +0000, JohnB wrote:

You amaze me. I am getting used to my boiler costing a fortune.

A dreaded Potterton Flowshure+ hence integral but (for once) easily
removable tank. Being Potterton it may be much more expensive than
normal to
get the shape that fits. If so could be a good idea to fit an external
one
for that price.

[Please don't reply at the top. ]
If the one in the boiler is easily exchanged (they usually are very
inaccessible) then the manufacturers replacement is worth paying the extra
(probably double) over a generaic component that would have to be fitted
elsewhere.

If you do replace it with a generic vessel, fit it on the return pipe.

What's the reason for that?

--
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

"Ed Sirett" wrote in message
news
On Sun, 15 Feb 2004 22:29:38 +0000, IMM wrote:


"Ed Sirett" wrote in message
news
On Sun, 15 Feb 2004 16:49:00 +0000, JohnB wrote:

You amaze me. I am getting used to my boiler costing a fortune.

A dreaded Potterton Flowshure+ hence integral but (for once) easily
removable tank. Being Potterton it may be much more expensive than
normal to
get the shape that fits. If so could be a good idea to fit an
external
one
for that price.

[Please don't reply at the top. ]
If the one in the boiler is easily exchanged (they usually are very
inaccessible) then the manufacturers replacement is worth paying the
extra
(probably double) over a generaic component that would have to be
fitted
elsewhere.

If you do replace it with a generic vessel, fit it on the return pipe.

What's the reason for that?

Cooler, and you will find that most system/combi boilers have them there
anyhow.

Thanks for all the info folks.

A generic tank on the return it will be.

JohnB

"Ed Sirett" wrote in message
news
On Sun, 15 Feb 2004 23:11:07 +0000, IMM wrote:


"john.bunting" wrote in message
...
I have just checked HRPC online (thanks for you commenting elsewhere
that
they had an online site). £197 for the correct potterton retail
13.5L
expansion tank .....gasp ...... Even trade will be pricey. I see they
have
Altecnic 18L at £39. The max working bar allowed is 4 so still should
be
OK.

Looks as if they have to be fitted the correct way round. Would not
have
thought of that.

Perhaps it would be cheaper in the long run to put a well lagged
radiator
in
the loft and keep it filled with air!!!

Using a rad is temp solution. Use a proper pressure vessel.

Agreed, there are issues withthe air disolving into the water and coming
out elsewhere, if nothing else.


--
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

Any idea as to where i might find this car-type valve as i removed the
cover but could not see anything... saw a silver covered rectangle
(where the gas lights up) and below that some pipes, wires, and pump.

So back to the original question would i find the car-type valve if i
removed the cover from the silver rectangular gas chamber?

On Thu, 19 Feb 2004 10:46:43 +0000, Shabs wrote:

Any idea as to where i might find this car-type valve as i removed the
cover but could not see anything... saw a silver covered rectangle
(where the gas lights up) and below that some pipes, wires, and pump.

So back to the original question would i find the car-type valve if i
removed the cover from the silver rectangular gas chamber?

I'm not familiar with this model, but in most designs the
expansion vessel is very awkwardly located behind the combustion chamber.
You may find it is painted red/brown (no reason why except they nearly all
are). The air side valve may be accessible from above the whole unit.


--
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