Wot I need is someone who has a circuit diagram and can tell me what the
specification of the temperature setting pot on the PCB of this boiler is
(new green LED PCB).

Boiler water carries on getting hotter and hotter until elderly pump starts
complaining (pump OK at lower temperatures). Changed thermistor, as it's
cheaper than PCB, but no change (measured old one in the end and nowt wrong
with that either). Measured temperature setting pot which seems to be open
circuit in the middle 30% of its range and bizarre either side. Object to
paying £124 for a new PCB if it's just a pot!

Any boiler anoraks out there with a circuit diagram/parts list? Can't remove
part as want boiler to function (as best it can).

--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

On 3 Apr, 08:35, "Bob Mannix" wrote:
Wot I need is someone who has a circuit diagram and can tell me what the
specification of the temperature setting pot on the PCB of this boiler is
(new green LED PCB).

Boiler water carries on getting hotter and hotter until elderly pump starts
complaining (pump OK at lower temperatures). Changed thermistor, as it's
cheaper than PCB, but no change (measured old one in the end and nowt wrong
with that either). Measured temperature setting pot which seems to be open
circuit in the middle 30% of its range and bizarre either side. Object to
paying £124 for a new PCB if it's just a pot!

Any boiler anoraks out there with a circuit diagram/parts list? Can't remove
part as want boiler to function (as best it can).

I got a replacement Micron PCB off ebay for £30 in Jan and fixed my
boiler. Brand new genuine part.

There's a guy who posts here who refurbs the PCB's, so he may be able
to help.

In message , Bob Mannix
writes
Wot I need is someone who has a circuit diagram and can tell me what the
specification of the temperature setting pot on the PCB of this boiler is
(new green LED PCB).

Do you mean the interconnection diagram ?


Boiler water carries on getting hotter and hotter until elderly pump starts
complaining (pump OK at lower temperatures). Changed thermistor, as it's
cheaper than PCB, but no change (measured old one in the end and nowt wrong
with that either). Measured temperature setting pot which seems to be open
circuit in the middle 30% of its range and bizarre either side. Object to
paying £124 for a new PCB if it's just a pot!

It won't give a linear reading, it's part of a chain


Any boiler anoraks out there with a circuit diagram/parts list?

No

Can't remove
part as want boiler to function (as best it can).


better ring me tomorrow

phone number on the website - www.cetltd.com

--
geoff

"geoff" wrote in message
...
In message , Bob Mannix
writes
Wot I need is someone who has a circuit diagram and can tell me what the
specification of the temperature setting pot on the PCB of this boiler is
(new green LED PCB).

Do you mean the interconnection diagram ?

Well I meant a circuit diagram but we may mean the same thing! I don't want
how the boiler parts are connected together but the circuit diagram for the
PCB.



Boiler water carries on getting hotter and hotter until elderly pump
starts
complaining (pump OK at lower temperatures). Changed thermistor, as it's
cheaper than PCB, but no change (measured old one in the end and nowt
wrong
with that either). Measured temperature setting pot which seems to be open
circuit in the middle 30% of its range and bizarre either side. Object to
paying £124 for a new PCB if it's just a pot!

It won't give a linear reading, it's part of a chain

That wouldn't explain open circuit in the centre of the travel. I'm guessing
its (probably) a 0-20k linear pot but that's only a guess, as the thermistor
is 2.5k-14k across its dynamic range and, intuitively, one might assume them
to be similar (while holding to the maxim that assumption is the mother of
all cock-ups!). Yes, removing it would be better but, with it right down to
zero on the dial, I can just about keep things running at present so didn't
want to remove it. I made my measurements with the board itself removed and
disconnected, of course.


Any boiler anoraks out there with a circuit diagram/parts list?

No

Can't remove
part as want boiler to function (as best it can).


better ring me tomorrow

I am bidding for a new PCB on ebay at present, which would be quicker, but
many thanks for the offer - I may take it up if the bid fails!


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

phone number on the website - www.cetltd.com

--
geoff

"Bob Mannix" wrote in message
...
"geoff" wrote in message
...
In message , Bob Mannix
writes
Wot I need is someone who has a circuit diagram and can tell me what the
specification of the temperature setting pot on the PCB of this boiler is
(new green LED PCB).

Do you mean the interconnection diagram ?

Well I meant a circuit diagram but we may mean the same thing! I don't
want how the boiler parts are connected together but the circuit diagram
for the PCB.



Boiler water carries on getting hotter and hotter until elderly pump
starts
complaining (pump OK at lower temperatures). Changed thermistor, as it's
cheaper than PCB, but no change (measured old one in the end and nowt
wrong
with that either). Measured temperature setting pot which seems to be
open
circuit in the middle 30% of its range and bizarre either side. Object to
paying £124 for a new PCB if it's just a pot!

It won't give a linear reading, it's part of a chain

That wouldn't explain open circuit in the centre of the travel. I'm
guessing its (probably) a 0-20k linear pot but that's only a guess, as the
thermistor is 2.5k-14k across its dynamic range and, intuitively, one
might assume them to be similar (while holding to the maxim that
assumption is the mother of all cock-ups!). Yes, removing it would be
better but, with it right down to zero on the dial, I can just about keep
things running at present so didn't want to remove it. I made my
measurements with the board itself removed and disconnected, of course.


Any boiler anoraks out there with a circuit diagram/parts list?

No

Can't remove
part as want boiler to function (as best it can).


better ring me tomorrow

I am bidding for a new PCB on ebay at present, which would be quicker, but
many thanks for the offer - I may take it up if the bid fails!

Or, indeed, a reconditioned one from you, I should have added! I have
bookmarked the page!

Cheers,


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

In message , Bob Mannix
writes
"geoff" wrote in message
...
In message , Bob Mannix
writes
Wot I need is someone who has a circuit diagram and can tell me what the
specification of the temperature setting pot on the PCB of this boiler is
(new green LED PCB).

Do you mean the interconnection diagram ?

Well I meant a circuit diagram but we may mean the same thing! I don't want
how the boiler parts are connected together but the circuit diagram for the
PCB.

Your chance is probably somewhere between nought and zero

Also, there are two different versions of the board - the old version
with discrete components and 6 neons on the pcb, and the later
version(s) with 2 green LEDs and not a lot else other than two PICs
(version 3 has a microcontroller)






Boiler water carries on getting hotter and hotter until elderly pump
starts
complaining (pump OK at lower temperatures). Changed thermistor, as it's
cheaper than PCB, but no change (measured old one in the end and nowt
wrong
with that either). Measured temperature setting pot which seems to be open
circuit in the middle 30% of its range and bizarre either side. Object to
paying £124 for a new PCB if it's just a pot!

It won't give a linear reading, it's part of a chain

That wouldn't explain open circuit in the centre of the travel. I'm guessing
its (probably) a 0-20k linear pot

It's stamped on the pot

but that's only a guess, as the thermistor
is 2.5k-14k across its dynamic range and, intuitively, one might assume them
to be similar (while holding to the maxim that assumption is the mother of
all cock-ups!). Yes, removing it would be better but, with it right down to
zero on the dial, I can just about keep things running at present so didn't
want to remove it. I made my measurements with the board itself removed and
disconnected, of course.


Any boiler anoraks out there with a circuit diagram/parts list?

No

Can't remove
part as want boiler to function (as best it can).


better ring me tomorrow

I am bidding for a new PCB on ebay at present, which would be quicker, but
many thanks for the offer - I may take it up if the bid fails!



--
geoff