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Default Combi - replacing circuit board

A very helpful engineer called today to look at the combi - boiler which
makes good heating but feeble hot water. The conclusion is that the gas
pressure after the modulating valve is too low: 4-5mB whereas the Glow-worm
Compact 100e instructions say this should be 15.5mB from cold. The mains
pressure is 21mB. It is not the thermistors, checked by swapping for new. So
it is either gas valve or the PCB.

New the PCB is about £135 but a refurbished one is to be had from an eBay
supplier at £50. I am minded to try the refurbished - I can do the swap
easily. But I suppose I need to get the engineer back to check the
pressures - a gas manometer is a specialised tool. Or I might chance that
the potentiometers on mid-setting are about right - better than now anyway.

I don't mind getting the man back at £48 per hour - it would take only 10
minutes and if it is not the board then I need him to change the gas valve
anyway. Anyone any advice on this?



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Default Combi - replacing circuit board

In article , Geoff Pearson
writes
A very helpful engineer called today to look at the combi - boiler which
makes good heating but feeble hot water. The conclusion is that the gas
pressure after the modulating valve is too low: 4-5mB whereas the Glow-worm
Compact 100e instructions say this should be 15.5mB from cold. The mains
pressure is 21mB. It is not the thermistors, checked by swapping for new. So
it is either gas valve or the PCB.

New the PCB is about £135 but a refurbished one is to be had from an eBay
supplier at £50. I am minded to try the refurbished - I can do the swap
easily. But I suppose I need to get the engineer back to check the
pressures - a gas manometer is a specialised tool. Or I might chance that
the potentiometers on mid-setting are about right - better than now anyway.

I don't mind getting the man back at £48 per hour - it would take only 10
minutes and if it is not the board then I need him to change the gas valve
anyway. Anyone any advice on this?

Do you have a multimeter that you could perform some tests with?

The thing to do is to operate the boiler alternately on heating and then
on hot water, and check the gas valve control voltages. If they are
within spec then it is reasonable to assume that the gas valve is not
operating correctly but they are not then expect a problem with the
board, or that the helpful engineer or someone else has been fiddling
with controls that they didn't understand.

The installer manual is not particularly helpful in this area but it
does tell you what to expect on the gas valve control wires under full
demand, See the table at the bottom of page 29 To Check for Component
Operation/Failure under Section 13.1 Fault Finding.

See also Section 10.5 Gas Rate Modulation and diagram 10.2, a competent
technician really should have checked these things out.

Manual he

http://www.glow-worm.co.uk/stepone/d...ompact100e.pdf


If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.
--
fred
it's a ba-na-na . . . .
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Default Combi - replacing circuit board


"fred" wrote in message ...
In article , Geoff Pearson
writes
A very helpful engineer called today to look at the combi - boiler which
makes good heating but feeble hot water. The conclusion is that the gas
pressure after the modulating valve is too low: 4-5mB whereas the
Glow-worm
Compact 100e instructions say this should be 15.5mB from cold. The mains
pressure is 21mB. It is not the thermistors, checked by swapping for new.
So
it is either gas valve or the PCB.

New the PCB is about £135 but a refurbished one is to be had from an eBay
supplier at £50. I am minded to try the refurbished - I can do the swap
easily. But I suppose I need to get the engineer back to check the
pressures - a gas manometer is a specialised tool. Or I might chance that
the potentiometers on mid-setting are about right - better than now
anyway.

I don't mind getting the man back at £48 per hour - it would take only 10
minutes and if it is not the board then I need him to change the gas valve
anyway. Anyone any advice on this?

Do you have a multimeter that you could perform some tests with?

The thing to do is to operate the boiler alternately on heating and then
on hot water, and check the gas valve control voltages. If they are within
spec then it is reasonable to assume that the gas valve is not operating
correctly but they are not then expect a problem with the board, or that
the helpful engineer or someone else has been fiddling with controls that
they didn't understand.

The installer manual is not particularly helpful in this area but it does
tell you what to expect on the gas valve control wires under full demand,
See the table at the bottom of page 29 To Check for Component
Operation/Failure under Section 13.1 Fault Finding.

See also Section 10.5 Gas Rate Modulation and diagram 10.2, a competent
technician really should have checked these things out.

Manual he

http://www.glow-worm.co.uk/stepone/d...ompact100e.pdf


If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.
--
fred
it's a ba-na-na . . . .


I had downloaded the manual - after the engineer had been. I'm a licensed
radio amateur (GM8BHR), have a degree in physics and used to be in
electronics (but I'm colour-blind). The engineer, with my help, checked the
voltages. They are 24-26v, unchanging - no matter what the pots are set to.
Glow-worm, on the phone, said the voltage would vary 24-50v (as does page
29). Nothing moves a mV on my board. However, page 22 says set up with a
pressure reading and that is my problem. The boiler fires up and runs,
heats radiators and some tap water - but flame size looks a bit feeble.

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Default Combi - replacing circuit board

In article , Geoff Pearson
writes

I had downloaded the manual - after the engineer had been. I'm a licensed
radio amateur (GM8BHR), have a degree in physics and used to be in
electronics (but I'm colour-blind). The engineer, with my help, checked the
voltages. They are 24-26v, unchanging - no matter what the pots are set to.
Glow-worm, on the phone, said the voltage would vary 24-50v (as does page
29). Nothing moves a mV on my board. However, page 22 says set up with a
pressure reading and that is my problem. The boiler fires up and runs,
heats radiators and some tap water - but flame size looks a bit feeble.

The manual isn't the most detailed in this area but let's assume that
24V is for minimum modulation and that 50V maxes it. If you've checked
the inputs to the system and the outputs aren't performing as expected
(not maxing on h/w demand) then it is pointing to the board.

You don't need to rely on the colours for the fault finding as the
positions of the outputs on the board are shown on the diagrams, just
count pins.

By all means get the technician back in to set your pressures accurately
(if you're not confident using a manometer (or making one) yourself) but
you should be able to see if they are substantially correct from the
size of the flame.
--
fred
it's a ba-na-na . . . .
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Default Combi - replacing circuit board

On Dec 20, 6:03*pm, fred wrote:
In article , Geoff Pearson
writes

I had downloaded the manual - after the engineer had been. * I'm a licensed
radio amateur (GM8BHR), have a degree in physics and used to be in
electronics (but I'm colour-blind). *The engineer, with my help, checked the
voltages. *They are 24-26v, unchanging - no matter what the pots are set to.
Glow-worm, on the phone, said the voltage would vary 24-50v (as does page
29). *Nothing moves a mV on my board. *However, page 22 says set up with a
pressure reading and that is my problem. *The boiler fires up and runs,
heats radiators and some tap water - but flame size looks a bit feeble.


The manual isn't the most detailed in this area but let's assume that
24V is for minimum modulation and that 50V maxes it. If you've checked
the inputs to the system and the outputs aren't performing as expected
(not maxing on h/w demand) then it is pointing to the board.

You don't need to rely on the colours for the fault finding as the
positions of the outputs on the board are shown on the diagrams, just
count pins.

By all means get the technician back in to set your pressures accurately
(if you're not confident using a manometer (or making one) yourself) but
you should be able to see if they are substantially correct from the
size of the flame.
--


On a related note - the rubber hose for my manometer has a 1/4" bore.
It fits just fine over the test point in the boiler - but not the test
point in the boiler, which has an external diameter rather larger than
1/4". On the basis that "if it's that difficult, you must be doing it
wrong", there must be something I'm missing....

I've found this part - http://www.reginproducts.co.uk/flowandpressure/REGU01
- which will clearly do the job, but I can't believe this is the only
way of doing it.




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Default Combi - replacing circuit board

In message , fred writes
In article , Geoff Pearson
writes
A very helpful engineer called today to look at the combi - boiler which
makes good heating but feeble hot water. The conclusion is that the gas
pressure after the modulating valve is too low: 4-5mB whereas the Glow-worm
Compact 100e instructions say this should be 15.5mB from cold. The mains
pressure is 21mB. It is not the thermistors, checked by swapping for new. So
it is either gas valve or the PCB.

New the PCB is about £135 but a refurbished one is to be had from an eBay
supplier at £50. I am minded to try the refurbished - I can do the swap
easily. But I suppose I need to get the engineer back to check the
pressures - a gas manometer is a specialised tool. Or I might chance that
the potentiometers on mid-setting are about right - better than now anyway.

I don't mind getting the man back at £48 per hour - it would take only 10
minutes and if it is not the board then I need him to change the gas valve
anyway. Anyone any advice on this?

Do you have a multimeter that you could perform some tests with?

The thing to do is to operate the boiler alternately on heating and
then on hot water, and check the gas valve control voltages. If they
are within spec then it is reasonable to assume that the gas valve is
not operating correctly but they are not then expect a problem with the
board, or that the helpful engineer or someone else has been fiddling
with controls that they didn't understand.

The installer manual is not particularly helpful in this area but it
does tell you what to expect on the gas valve control wires under full
demand, See the table at the bottom of page 29 To Check for Component
Operation/Failure under Section 13.1 Fault Finding.

See also Section 10.5 Gas Rate Modulation and diagram 10.2, a competent
technician really should have checked these things out.

Manual he

http://www.glow-worm.co.uk/stepone/d...ompact100e.pdf


If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.


Yup, out tomorrow SHOULD be delivered on thursday, don't hold your
breath, the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they have
just had a £250,000 CCJ against them from HMRC for tax evasion

--
geoff
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Posts: 283
Default Combi - replacing circuit board


"geoff" wrote in message
...
In message , fred writes
In article , Geoff Pearson
writes
A very helpful engineer called today to look at the combi - boiler which
makes good heating but feeble hot water. The conclusion is that the gas
pressure after the modulating valve is too low: 4-5mB whereas the
Glow-worm
Compact 100e instructions say this should be 15.5mB from cold. The mains
pressure is 21mB. It is not the thermistors, checked by swapping for new.
So
it is either gas valve or the PCB.

New the PCB is about £135 but a refurbished one is to be had from an eBay
supplier at £50. I am minded to try the refurbished - I can do the swap
easily. But I suppose I need to get the engineer back to check the
pressures - a gas manometer is a specialised tool. Or I might chance
that
the potentiometers on mid-setting are about right - better than now
anyway.

I don't mind getting the man back at £48 per hour - it would take only 10
minutes and if it is not the board then I need him to change the gas
valve
anyway. Anyone any advice on this?

Do you have a multimeter that you could perform some tests with?

The thing to do is to operate the boiler alternately on heating and then
on hot water, and check the gas valve control voltages. If they are within
spec then it is reasonable to assume that the gas valve is not operating
correctly but they are not then expect a problem with the board, or that
the helpful engineer or someone else has been fiddling with controls that
they didn't understand.

The installer manual is not particularly helpful in this area but it does
tell you what to expect on the gas valve control wires under full demand,
See the table at the bottom of page 29 To Check for Component
Operation/Failure under Section 13.1 Fault Finding.

See also Section 10.5 Gas Rate Modulation and diagram 10.2, a competent
technician really should have checked these things out.

Manual he

http://www.glow-worm.co.uk/stepone/d...ompact100e.pdf


If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.


Yup, out tomorrow SHOULD be delivered on thursday, don't hold your breath,
the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they have
just had a £250,000 CCJ against them from HMRC for tax evasion

--
geoff


I ordered from CET this morning and they think it might be here on Christmas
Eve. Great service. Geoff

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Posts: 6,896
Default Combi - replacing circuit board

If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.


Yup, out tomorrow SHOULD be delivered on thursday, don't hold your breath,
the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they have
just had a £250,000 CCJ against them from HMRC for tax evasion

--
geoff




I ordered from CET this morning and they think it might be here on Christmas
Eve. Great service. Geoff


Just second that!, he got us out of some serious bother last year in the
coldest bit of the year;!...
--
Tony Sayer

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Posts: 3,819
Default Combi - replacing circuit board

In message , Geoff Pearson
writes

"geoff" wrote in message
...
In message , fred writes
In article , Geoff Pearson
writes
A very helpful engineer called today to look at the combi - boiler which
makes good heating but feeble hot water. The conclusion is that the gas
pressure after the modulating valve is too low: 4-5mB whereas the
Glow-worm
Compact 100e instructions say this should be 15.5mB from cold. The mains
pressure is 21mB. It is not the thermistors, checked by swapping for
new. So
it is either gas valve or the PCB.

New the PCB is about £135 but a refurbished one is to be had from an eBay
supplier at £50. I am minded to try the refurbished - I can do the swap
easily. But I suppose I need to get the engineer back to check the
pressures - a gas manometer is a specialised tool. Or I might
chance that
the potentiometers on mid-setting are about right - better than now
anyway.

I don't mind getting the man back at £48 per hour - it would take only 10
minutes and if it is not the board then I need him to change the gas
valve
anyway. Anyone any advice on this?

Do you have a multimeter that you could perform some tests with?

The thing to do is to operate the boiler alternately on heating and
then on hot water, and check the gas valve control voltages. If they
are within spec then it is reasonable to assume that the gas valve is
not operating correctly but they are not then expect a problem with
the board, or that the helpful engineer or someone else has been
fiddling with controls that they didn't understand.

The installer manual is not particularly helpful in this area but it
does tell you what to expect on the gas valve control wires under
full demand, See the table at the bottom of page 29 To Check for
Component Operation/Failure under Section 13.1 Fault Finding.

See also Section 10.5 Gas Rate Modulation and diagram 10.2, a
competent technician really should have checked these things out.

Manual he

http://www.glow-worm.co.uk/stepone/d...ompact100e.pdf


If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're
shutting down from Christmas from noon tomorrow.


Yup, out tomorrow SHOULD be delivered on thursday, don't hold your
breath, the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they
have just had a £250,000 CCJ against them from HMRC for tax evasion

-- geoff


I ordered from CET this morning and they think it might be here on
Christmas Eve. Great service. Geoff


We do our best

--
geoff
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Default Combi - replacing circuit board

In article , geoff
writes
In message , fred writes

If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.


Yup, out tomorrow SHOULD be delivered on thursday, don't hold your
breath, the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they have
just had a £250,000 CCJ against them from HMRC for tax evasion

Thought I'd heard you say something along those lines before but thought
I'd let you issue the warning first hand. Certainly safer to deal with
someone like yourself who has an established presence, has their own
website and is available on the phone for queries.
--
fred
it's a ba-na-na . . . .


  #11   Report Post  
Posted to uk.d-i-y
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Posts: 3,819
Default Combi - replacing circuit board

In message , fred writes
In article , geoff
writes
In message , fred writes

If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.


Yup, out tomorrow SHOULD be delivered on thursday, don't hold your
breath, the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they have
just had a £250,000 CCJ against them from HMRC for tax evasion

Thought I'd heard you say something along those lines before but
thought I'd let you issue the warning first hand. Certainly safer to
deal with someone like yourself who has an established presence, has
their own website and is available on the phone for queries.


Received this today

I thought I'd share (a board we send out with a 12 month warranty for
£50 ++)

"Hi, I found you via Google and wondered if you would be interested in
purchasing a failed PCB from me? Part number 87483004170 (photo of
actual PCB attached).

It is from my Worcester 24si ii which was intermittently not lighting,
the boiler switched on but there was no ignition spark and it would
eventually lock out. The board has now been replaced but I have a
feeling the old one can probably be repaired.

I noticed someone selling the same faulty board on eBay for £40 +
delivery
(http://www.ebay.co.uk/itm/WORCESTER-...CIRCUIT-BOARD-
28Si-II-24Si-II-/261144861681). Would you be interested in this for £30
and I will include delivery in that"

made oi laff, anyway



--
geoff
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Posts: 283
Default Combi - replacing circuit board


"geoff" wrote in message
...
In message , fred writes
In article , geoff
writes
In message , fred writes

If you want a board then look know further than our own Geoff at
http://cetltd.com/ but don't hang about it looks like they're shutting
down from Christmas from noon tomorrow.

Yup, out tomorrow SHOULD be delivered on thursday, don't hold your
breath, the couriers are under pressure

It sounds like its not an urgent problem, i.e. the boiler is still
actually working. Modulation control is a fairly common problem with
compact 80/100 pcbs. I think I have some left in stock

buy from ebay at your peril. If its the company I think it is, they have
just had a £250,000 CCJ against them from HMRC for tax evasion

Thought I'd heard you say something along those lines before but thought
I'd let you issue the warning first hand. Certainly safer to deal with
someone like yourself who has an established presence, has their own
website and is available on the phone for queries.


Received this today

I thought I'd share (a board we send out with a 12 month warranty for £50
++)

"Hi, I found you via Google and wondered if you would be interested in
purchasing a failed PCB from me? Part number 87483004170 (photo of actual
PCB attached).

It is from my Worcester 24si ii which was intermittently not lighting, the
boiler switched on but there was no ignition spark and it would eventually
lock out. The board has now been replaced but I have a feeling the old one
can probably be repaired.

I noticed someone selling the same faulty board on eBay for £40 + delivery
(http://www.ebay.co.uk/itm/WORCESTER-...CIRCUIT-BOARD-
28Si-II-24Si-II-/261144861681). Would you be interested in this for £30
and I will include delivery in that"

made oi laff, anyway



--
geoff


geoff

my board, ordered from you on Friday arrived this afternoon - so will have a
session on Boxing Day fitting it and getting the old one back to you pdq.

Geoff

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