Seasons greetings

My Suprima 100 has died - or is trying to die.

Greeted on return home by the flashing red LED indicating lockout or
similar failure.

Pressing the reset button resulted in three attempts to ignite the gas
with plenty of fan noise, sparking at the spark gap but no ignition of gas.

sigh

So, I removed the covers and front insulation cover (the bit that gives
access to the burner jets). Had a look around for dust and other
foreign bodies. All is clean and tidy.

Ran through the fault finding list in the handbook except for the bit
that requires measuring the voltage across the gas valve. Still would
not light after three attempts. B*******s, it's the gas valve. Tried
to light it a couple more times prior to finding meter to check supply
to gas valve and then it did light but with a very jerky flame -
remember the front cover to the burner is off so maybe there is the
wrong amount of air.

Joy! Switched off.

Put the insulating cover back on and turned it all on again. Back to
three failed attempts followed by lockout.

sigh

Removed insulating cover and tried again. It lit with a proper flame.
Gingerly refitted the insulating cover keeping fingers well clear of
blower motor fan (previous bad experience). Boiler continued to run.
Refitted main covers.


No, I haven't dared resetting it in case it dies.

Can anyone suggest a fruitful line of research or thinking as to what
may be wrong?


TIA

Richard

Richard Savage wrote:
Seasons greetings

My Suprima 100 has died - or is trying to die.

Greeted on return home by the flashing red LED indicating lockout or
similar failure.

Pressing the reset button resulted in three attempts to ignite the gas
with plenty of fan noise, sparking at the spark gap but no ignition
of gas.
sigh

So, I removed the covers and front insulation cover (the bit that
gives access to the burner jets). Had a look around for dust and
other foreign bodies. All is clean and tidy.

Ran through the fault finding list in the handbook except for the bit
that requires measuring the voltage across the gas valve. Still would
not light after three attempts. B*******s, it's the gas valve. Tried
to light it a couple more times prior to finding meter to check supply
to gas valve and then it did light but with a very jerky flame -
remember the front cover to the burner is off so maybe there is the
wrong amount of air.

Joy! Switched off.

Put the insulating cover back on and turned it all on again. Back to
three failed attempts followed by lockout.

sigh

Removed insulating cover and tried again. It lit with a proper flame.
Gingerly refitted the insulating cover keeping fingers well clear of
blower motor fan (previous bad experience). Boiler continued to run.
Refitted main covers.


No, I haven't dared resetting it in case it dies.

Can anyone suggest a fruitful line of research or thinking as to what
may be wrong?


TIA

Richard

Air in the gas pipes?.....the jerky flame may suggest this, FWIW I ran my
last boiler for six months with the front cover off because I had to remove
it every time the gas went to relight the pilot (prepayment meter), and it
didn't burn with a jerky kind of flame.

--
Phil L
RSRL Tipster Of The Year 2008

In article , Richard Savage
scribeth thus
Seasons greetings

My Suprima 100 has died - or is trying to die.

Greeted on return home by the flashing red LED indicating lockout or
similar failure.

Pressing the reset button resulted in three attempts to ignite the gas
with plenty of fan noise, sparking at the spark gap but no ignition of gas.

sigh

So, I removed the covers and front insulation cover (the bit that gives
access to the burner jets). Had a look around for dust and other
foreign bodies. All is clean and tidy.

Ran through the fault finding list in the handbook except for the bit
that requires measuring the voltage across the gas valve. Still would
not light after three attempts. B*******s, it's the gas valve. Tried
to light it a couple more times prior to finding meter to check supply
to gas valve and then it did light but with a very jerky flame -
remember the front cover to the burner is off so maybe there is the
wrong amount of air.

Joy! Switched off.

Put the insulating cover back on and turned it all on again. Back to
three failed attempts followed by lockout.

sigh

Removed insulating cover and tried again. It lit with a proper flame.
Gingerly refitted the insulating cover keeping fingers well clear of
blower motor fan (previous bad experience). Boiler continued to run.
Refitted main covers.


No, I haven't dared resetting it in case it dies.

Can anyone suggest a fruitful line of research or thinking as to what
may be wrong?


TIA

Richard

If all else fails get a soldering iron and go over all the joints on the
PCB unit these are very good at developing intermittent dry joints...

and if no go cetled for a replacement board;!..
--
Tony Sayer

tony sayer wrote:


If all else fails get a soldering iron and go over all the joints on the
PCB unit these are very good at developing intermittent dry joints...

and if no go cetled for a replacement board;!..

Replaced the PCB via CET to cure the frequent lock out problem (which it
did) after waving a soldering iron across everything failed. That was 3
years ago so it might be feeling in need of a change. If it needs
replacing after 3 years I consider the money spent at CET very good
value - as was the telephone help I received from them when confirming
that I did need the PCB. No relation etc - just a satisfied customer.

Richard

On 23 Dec, 22:12, Richard Savage wrote:
Seasons greetings

My Suprima 100 has died - or is trying to die.

Greeted on return home by the flashing red LED indicating lockout or
similar failure.

Pressing the reset button resulted in three attempts to ignite the gas
with plenty of fan noise, sparking at the spark gap but no ignition of gas.

sigh

So, I removed the covers and front insulation cover (the bit that gives
access to the burner jets). *Had a look around for dust and other
foreign bodies. *All is clean and tidy.

Ran through the fault finding list in the handbook except for the bit
that requires measuring the voltage across the gas valve. *Still would
not light after three attempts. *B*******s, it's the gas valve. *Tried
to light it a couple more times prior to finding meter to check supply
to gas valve and then it did light but with a very jerky flame -
remember the front cover to the burner is off so maybe there is the
wrong amount of air.

Joy! *Switched off.

Put the insulating cover back on and turned it all on again. * Back to
three failed attempts followed by lockout.

sigh

Removed insulating cover and tried again. *It lit with a proper flame.
Gingerly refitted the insulating cover keeping fingers well clear of
blower motor fan (previous bad experience). *Boiler continued to run.
Refitted main covers.

No, I haven't dared resetting it in case it dies.

Can anyone suggest a fruitful line of research or thinking as to what
may be wrong?

TIA

Richard

The open cover probably allows more airflow through the fan/flue
system and MAY be indicative of an airflow sensing problem. Try
removing the sensing tubes from the airlow sensor and blowing them
clear. Also check the fan blades are clean and the air/flue route is
similarly clear and clean. One of the Pottertons used an odd thermal
airflow sensor but others I believe have a simple differential
pressure switch.
I can't recall if the sparking starts before or after the airflow is
proved but the fact the flame ignites with the cover off suggests the
above.

In message
,
cynic writes

The open cover probably allows more airflow through the fan/flue
system and MAY be indicative of an airflow sensing problem. Try
removing the sensing tubes from the airlow sensor and blowing them
clear. Also check the fan blades are clean and the air/flue route is
similarly clear and clean. One of the Pottertons used an odd thermal
airflow sensor

Lynx 1

but others I believe have a simple differential
pressure switch.

The Suprima has a 2 wire standard APS

I can't recall if the sparking starts before or after the airflow is
proved

Tut tut ...

Until the APS transfers, there is no spark or power to the gas valve

but the fact the flame ignites with the cover off suggests the
above.


Happy Xmas John


--
geoff