micron 30ff cuts out after "successful" lighting sequence
 

Hi,

I have a trusty 2 year old Micron 30FF that is causing me some grief.
It successfully lights on every firing sequence (I have the front off
and can see the blue glow of the flames) but at the end of the sequence
the gas is cut and obviously it doesn't stay lit!

I had a professional come and have a look (a friend) who squeezed one
of the pipes to the air switch for 40 seconds during the lighting
sequence - causing the fan to turn for much longer, and this caused it
to light once he'd let go. He said replace the air switch.

I've done this to no avail - same problem. It nearly always fires if
the fan is turning for 40 seconds before the rest of the lighting
sequence carries on.

The fault is one that says "software error" in the manual - great info.
Micron say dodgy earth or PCB. But why does it light when the fan is
forced to turn for longer?

Once warm it always lights on demand. Should I replace the thermistor
/ give up and get a new PCB?

Many thanks

Dave

micron 30ff cuts out after "successful" lighting sequence
 

Once warm it always lights on demand. Should I replace the thermistor
/ give up and get a new PCB?


Start with the cheapest option

micron 30ff cuts out after "successful" lighting sequence
 

On Mon, 23 Oct 2006 16:55:57 +0100, wrote:



Once warm it always lights on demand. Should I replace the thermistor
/ give up and get a new PCB?


Start with the cheapest option

The symptoms suggest that the flame detection process is faulty.

Looking at the manual and reading between the lines it looks as if there
is a two stage ignition (there are three wires + earth) going to the gas
valve. The first stage is happening but probably requires confimation of
the flame before going to full rate using the second solenoind on the
valve.

Problems with flame detection:

Dirt and crud and misposition of the ignition/sensing electrode.
Polarity of supply.
Earthing to and within the boiler.
Spark electrode (also used to detect the flame on this boiler) and its
lead. NB a small break will transmit a spark to lit the gas but fail to
detect the flame.
Also check the gas supply.

I think the APS stuff was a complete red herring.

Only when you have exhausted the low tech stuff then you should obtain a
recon'd PCB.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://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
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

micron 30ff cuts out after "successful" lighting sequence
 

Ed Sirett wrote:

Dirt and crud and misposition of the ignition/sensing electrode.
Polarity of supply.
Earthing to and within the boiler.
Spark electrode (also used to detect the flame on this boiler) and its
lead. NB a small break will transmit a spark to lit the gas but fail to
detect the flame.
Also check the gas supply.


To me, the fact that once it's warm it works no problem seems to point
towards the spark and its lead. There is a service part of the manual
and I have followed the procedure to clean and realign the electrode
properly.

However the fact Micron also mentioned the earth could easily put this
at the top of the list! How would I go about checking this - I have a
multimeter to hand.

Many thanks for your help,

Dave

micron 30ff cuts out after "successful" lighting sequence
 

In message .uk, Ed
Sirett writes
On Mon, 23 Oct 2006 16:55:57 +0100, wrote:



Once warm it always lights on demand. Should I replace the thermistor
/ give up and get a new PCB?


Start with the cheapest option

The symptoms suggest that the flame detection process is faulty.

Looking at the manual and reading between the lines it looks as if there
is a two stage ignition (there are three wires + earth) going to the gas
valve. The first stage is happening but probably requires confimation of
the flame before going to full rate using the second solenoind on the
valve.

Problems with flame detection:

Dirt and crud and misposition of the ignition/sensing electrode.
Polarity of supply.
Earthing to and within the boiler.
Spark electrode (also used to detect the flame on this boiler) and its
lead. NB a small break will transmit a spark to lit the gas but fail to
detect the flame.
Also check the gas supply.

I think the APS stuff was a complete red herring.

Only when you have exhausted the low tech stuff then you should obtain a
recon'd PCB.

I was wondering if it was a timing problem with one of the PICs

I was going to check it out on a test set tomorrow before replying


--
geoff

micron 30ff cuts out after "successful" lighting sequence
 

In message . com,
" writes

Ed Sirett wrote:

Dirt and crud and misposition of the ignition/sensing electrode.
Polarity of supply.
Earthing to and within the boiler.
Spark electrode (also used to detect the flame on this boiler) and its
lead. NB a small break will transmit a spark to lit the gas but fail to
detect the flame.
Also check the gas supply.


To me, the fact that once it's warm it works no problem seems to point
towards the spark and its lead. There is a service part of the manual
and I have followed the procedure to clean and realign the electrode
properly.

However the fact Micron also mentioned the earth could easily put this
at the top of the list! How would I go about checking this - I have a
multimeter to hand.

Zeroing out the lead resistance and with a half decent meter, you need
to check for a good earth between the supply, the earth at the electrode
and the earth on the pcb


--
geoff

micron 30ff cuts out after "successful" lighting sequence
 

raden wrote:
In message .uk, Ed
Sirett writes
On Mon, 23 Oct 2006 16:55:57 +0100, wrote:



Once warm it always lights on demand. Should I replace the thermistor
/ give up and get a new PCB?


Start with the cheapest option

The symptoms suggest that the flame detection process is faulty.

Looking at the manual and reading between the lines it looks as if there
is a two stage ignition (there are three wires + earth) going to the gas
valve. The first stage is happening but probably requires confimation of
the flame before going to full rate using the second solenoind on the
valve.

Problems with flame detection:

Dirt and crud and misposition of the ignition/sensing electrode.
Polarity of supply.
Earthing to and within the boiler.
Spark electrode (also used to detect the flame on this boiler) and its
lead. NB a small break will transmit a spark to lit the gas but fail to
detect the flame.
Also check the gas supply.

I think the APS stuff was a complete red herring.

Only when you have exhausted the low tech stuff then you should obtain a
recon'd PCB.

I was wondering if it was a timing problem with one of the PICs

I was going to check it out on a test set tomorrow before replying


--
geoff

ok, I will try that later tonight - many thanks

micron 30ff cuts out after "successful" lighting sequence
 

wrote:
raden wrote:
In message .uk, Ed
Sirett writes
On Mon, 23 Oct 2006 16:55:57 +0100, wrote:



Once warm it always lights on demand. Should I replace the thermistor
/ give up and get a new PCB?


Start with the cheapest option

The symptoms suggest that the flame detection process is faulty.

Looking at the manual and reading between the lines it looks as if there
is a two stage ignition (there are three wires + earth) going to the gas
valve. The first stage is happening but probably requires confimation of
the flame before going to full rate using the second solenoind on the
valve.

Problems with flame detection:

Dirt and crud and misposition of the ignition/sensing electrode.
Polarity of supply.
Earthing to and within the boiler.
Spark electrode (also used to detect the flame on this boiler) and its
lead. NB a small break will transmit a spark to lit the gas but fail to
detect the flame.
Also check the gas supply.

I think the APS stuff was a complete red herring.

Only when you have exhausted the low tech stuff then you should obtain a
recon'd PCB.

I was wondering if it was a timing problem with one of the PICs

I was going to check it out on a test set tomorrow before replying


--
geoff

ok, I will try that later tonight - many thanks

well, I tested all the earth points between each other and got a max
resistance of 7 ohms.

I took off each earth point and put it back on just in case of any
dodgy connections.

How does the electrode send a signal to tell the PCB that it's lit?
and does it make any difference that the control knob doesn't seem to
adjust the intensity of the flame at all?

cheers!

micron 30ff cuts out after "successful" lighting sequence
 

In message .com, Dave
Burton writes

I think the APS stuff was a complete red herring.

Only when you have exhausted the low tech stuff then you should obtain a
recon'd PCB.

I was wondering if it was a timing problem with one of the PICs

I was going to check it out on a test set tomorrow before replying


--
geoff

ok, I will try that later tonight - many thanks

well, I tested all the earth points between each other and got a max
resistance of 7 ohms.

Sounds OK


I took off each earth point and put it back on just in case of any
dodgy connections.

How does the electrode send a signal to tell the PCB that it's lit?
and does it make any difference that the control knob doesn't seem to
adjust the intensity of the flame at all?

A flame is like a lossy rectifier

There is circuitry on the pcb to sense this

The gas valve on the Micron is either switched on or off, the control
knob just affects the (water) temperature at which the gas valve is
switched


--
geoff

micron 30ff cuts out after "successful" lighting sequence
 

1) Dirt and crud and misposition of the ignition/sensing electrode.

Checked position - approx 4mm from burner surface

2) Polarity of supply.

Not sure on this - I am guessing it is OK if the burner lights after
the fan turns for a longer time

3) Earthing to and within the boiler.

Seems fine - checked, max 7 ohms

4) Spark electrode (also used to detect the flame on this boiler) and
its lead. NB a small break will transmit a spark to lit the gas but
fail to detect the flame.

Not replaced although seems like a cheap option - therefore good. Also
where's the best place to get a lead - I guess it's fire-proof?

5) Also check the gas supply.

Again, is this likely to be fine if the burner works all evening once
lit? Can anyone shed any more light on the fact it will stay lit if
the fan turns for 40 seconds before the ignition sequence?

Many thanks for all your help

Dave

micron 30ff cuts out after "successful" lighting sequence
 

replying to daveburton1, delta925 wrote:
The OP never updated this thread with the final solution.


I have a Micron 50FF that was fitted in 2004 and been 100% reliable until a
month ago.

With no warning or symptoms the indicators were Reset ON, Burner Lit Flashing
Slow indicating a software error.
No combination of totally removing power and the control knob would clear this.

The fan and pressure switch were tested by independently applying power to the
fan and monitoring the switch with a multimeter.
The thermistor was measured with the multimeter. As the temperature was more
like 5C than 20C a reading of 14K ohm was reasonable.
The overtemperature switch was measured and confirmed to be closed.
The control valve solenoid coils both measured around 900 ohms.

An advance exchange control board was ordered.
The original was a Pijnenburg type 227134 .
The exchange was ordered under the same code but a Ritter type labelled
2000227134 was received.
The Glowworm website conforms that the original Pektron 801990, Pijnenburg
227134 / 2000227134 and Ritter 2000227142 are interchangeable.
It would seem that the Ritter ( the final version ) has been boxed and labeled
as 2000801990, 2000227134 and 2000227142 .

Once the control board was swapped the burner lit first time but failed to
stay alight. After 3 attempt it locked out.
It seems that regardless of the power and control know sequence at least these
later boards lock out for a period of time. When the lockout finally could be
cleared at the second attempt ( 5 in total ) the burner stayed alight.

While the system was hot the burner turned off then relit controlled by the
thermistor without any problem.

However once off for a couple of hours the burner would not stay alight again.

It was at this point a search found this thread.

An electrode had already been ordered in case needed but was delivered a day
later.
Once fitted the burner lit at the second attempt and has not locked out since.

What this appears to show it that just because an electrode will create a
spark it may have deteriorated beyond the point where the burner flame can be
detected.

Also possibly the Ritter control board flame detection is less sensitive than
the Pijnenburg and / or the electrode deterioration actually caused the
control board failure as flame detection errors and lockouts were occurring
but not noticed.

While the Glowworm manual fault finding chart can not cover every possibility
not showing the burner igniting then the burner being lit as two stages is a
major omission.
For ' Does burner lit indicator come on ' no it could say check electrode
and wiring, faulty electrode, control board fault.

I hope this helps others with a Glowworm Micron 30FF, 40FF, 50FF and others
too e.g. 60FF, 70FF, Halstead Buckingham that use these or a similar control
board / circuit board / PCB.

--
for full context, visit https://www.homeownershub.com/uk-diy...ce-296371-.htm