A Different Potterton Problem
 

Can anyone help me with this please...
Suprima 60 with what seems like a thermostat problem
When boiler reaches it's preset temp it turns off correctly, [red on -
green flashing] but then 10 secs later red goes out and it re-fires.
30 secs later it again realises it's up to temp and goes off.
10 secs later Red goes out and green flashes [call for heat] but
this time it does not re-fire but goes into what I now realise is an
"anti cycle timeout" of about 5 mins. [green flashing all the time]
After the 5 mins, it suddenly decides to fire up and then it repeats
all the above again.
The temp at which it goes off for the first time, varies as you would
expect with the temp control setting.

I have checked the pump speed - four speed pump, - it is working well
and the speed makes no difference. [Pottertons theory was the pump
was too slow.]
I have replaced the thermistor - a waste of £11.

I have monitored the PCB around the voltage comparator [U5] which does
all the temp measuring/control, and it seems to be working well. The
o/p of the chip goes high when the two inputs match and drops a 10
secs later as the water temp drops. The red led follows the chip o/p.
I am beginning to wonder if this is a design prob, and so I would be
very grateful if anyone with a suprima could do a couple of tests for
me....

Set the temp to minimum [50deg approx] and fire it up with a constant
demand.
When the boiler reaches temp the red should come on and the green
flash
Q1. Does the red stay on all the while the boiler is up to temp? - or
does it go out after 10secs?
Q2. How long does it take for the temp to drop sufficiently to re-fire
the boiler?
Q3. What is the temp drop needed to make it re-fire - mine refires
when my thermometer shows about a 3 deg drop - ie almost immediately.

I am loath to buy a new PCB without being sure that it is faulty-
answers to the above questions would help a great deal

Thanks in advance

Phil

A Different Potterton Problem
 

In message , normandy16
writes
Can anyone help me with this please...
Suprima 60 with what seems like a thermostat problem
When boiler reaches it's preset temp it turns off correctly, [red on -
green flashing] but then 10 secs later red goes out and it re-fires.
30 secs later it again realises it's up to temp and goes off.
10 secs later Red goes out and green flashes [call for heat] but
this time it does not re-fire but goes into what I now realise is an
"anti cycle timeout" of about 5 mins. [green flashing all the time]
After the 5 mins, it suddenly decides to fire up and then it repeats
all the above again.
The temp at which it goes off for the first time, varies as you would
expect with the temp control setting.

Are the other timings repeatably the same, or iffy timings ?


I have checked the pump speed - four speed pump, - it is working well
and the speed makes no difference. [Pottertons theory was the pump
was too slow.]
I have replaced the thermistor - a waste of £11.

Are the rads getting warm, i.e is the system up to temperature - do you
have a blockage in the system?


I have monitored the PCB around the voltage comparator [U5] which does
all the temp measuring/control, and it seems to be working well. The
o/p of the chip goes high when the two inputs match and drops a 10
secs later as the water temp drops. The red led follows the chip o/p.
I am beginning to wonder if this is a design prob, and so I would be
very grateful if anyone with a suprima could do a couple of tests for
me....

The red LED should only be on when the temperature is satisfied (i.e.
hot or no call for heat (temp ctrl the temp sensor so to speak), as in
the table in the manual)


Set the temp to minimum [50deg approx] and fire it up with a constant
demand.
When the boiler reaches temp the red should come on and the green
flash
Q1. Does the red stay on all the while the boiler is up to temp? - or
does it go out after 10secs?
Q2. How long does it take for the temp to drop sufficiently to re-fire
the boiler?
Q3. What is the temp drop needed to make it re-fire - mine refires
when my thermometer shows about a 3 deg drop - ie almost immediately.

I am loath to buy a new PCB without being sure that it is faulty-
answers to the above questions would help a great deal

--
geoff

A Different Potterton Problem
 

geoff wrote in message ...

Are the other timings repeatably the same, or iffy timings ?

Yes, it is very constant in behaviour



Are the rads getting warm, i.e is the system up to temperature - do you
have a blockage in the system?

Yes, all rads get hot, I'm very confident there is no blockage.
Also tested using Hot water circuit only, ie a low resistance loop
[28mm to tank] and it is exactly the same



The red LED should only be on when the temperature is satisfied (i.e.
hot or no call for heat (temp ctrl the temp sensor so to speak), as in
the table in the manual)


agreed - it is the fact that mine goes out after 10 secs that I
believe is the problem


I think my next move is to replace U5 on the PCB but I don't really
think it is faulty. There is a deeper problem somewhere. The red LED
follows the output of U5 perfectly.
What I really need is info on the large chip -U9.
It is a Phillips chip but they do not admit to its existence on their
web site
2 numbers on it..
PHC_144095 which I think is a phillips code of some sort and..
K9V215 - which I think is the proper chip number
As I say - I can't find any info on either numbers. I gues its a micro
processor of some sort?
Anyone have any info please!


Thanks for the reply

P

A Different Potterton Problem
 

In message , normandy16
writes


I think my next move is to replace U5 on the PCB but I don't really
think it is faulty. There is a deeper problem somewhere. The red LED
follows the output of U5 perfectly.
What I really need is info on the large chip -U9.
It is a Phillips chip but they do not admit to its existence on their
web site
2 numbers on it..
PHC_144095 which I think is a phillips code of some sort and..
K9V215 - which I think is the proper chip number
As I say - I can't find any info on either numbers. I gues its a micro
processor of some sort?
Anyone have any info please!

Yes it's a microcontroller with proprietary software in, so you're on a
hiding to nowhere trying to replace it.

And yes, I would suspect this as being at fault

--
geoff

A Different Potterton Problem
 

What I really need is info on the large chip -U9.
It is a Phillips chip but they do not admit to its existence on their
web site
2 numbers on it..
PHC_144095 which I think is a phillips code of some sort and..
K9V215 - which I think is the proper chip number
As I say - I can't find any info on either numbers. I gues its a micro
processor of some sort?
Anyone have any info please!

Yes it's a microcontroller with proprietary software in, so you're on a
hiding to nowhere trying to replace it.

Ah! I had a nasty feeling this was the case

And yes, I would suspect this as being at fault

Hmm, looks like I need to shell out for a new board then!

Thanks for your help Geoff

Cheers

P

A Different Potterton Problem
 

In message , normandy16
writes
What I really need is info on the large chip -U9.
It is a Phillips chip but they do not admit to its existence on their
web site
2 numbers on it..
PHC_144095 which I think is a phillips code of some sort and..
K9V215 - which I think is the proper chip number
As I say - I can't find any info on either numbers. I gues its a micro
processor of some sort?
Anyone have any info please!

Yes it's a microcontroller with proprietary software in, so you're on a
hiding to nowhere trying to replace it.

Ah! I had a nasty feeling this was the case

And yes, I would suspect this as being at fault

Hmm, looks like I need to shell out for a new board then!

Better look at my website then - www.cetltd.com

--
geoff