Glowworm Micron 70FF lockouts

[Softus]

Has anyone been through the following tribulations? If so, can you offer me any advice?

1) Boiler make / model (gas or oil)
Glowworm / Micron 70FF (gas)

2) What is / is not happening
Customer reports that about twice per 24 hours the boiler will lock out. A reset will get it going again. While it's working it behaves impeccably.

3) Has ANYTHING else been done / changed recently
Yes. Glowworm recommended a new PCB, which was duly obtained and fitted. The frequency of lockouts reduced from several to about twice per 24 hours.

4) When did it (problem) start
About a month ago.

5) When does it happen? eg, heating coming on or going off
No perceivable pattern has emerged.

6) Anything else you feel may be of relevance
The system is fully pumped but has no controls on it. No roomstat, no cylinder stat, no motorised valves.
When the boiler needs resetting it the reset LED is on constantly and the burner LED flashes at about 2Hz.

TIA
softus
+++++++++++++++++++++++++++++++++++++++++++++

. one more thing...

After the PCB was replaced, Glowworm recommended replacing the thermister. I did so. The new one has resistance of 11KOhm (close enough to the spec) at room temperature, compared to the old one which was 6.7KOhm.

Sadly this made no difference to the frequency of lockouts.

MOD
please use the edit key

 

[PEDANTICVINDICTIVEMAN]

Had this sort of stupity with a 60ff, I had allready fitted a new board approxx 5 months previous so was unwilling to put another one in for free, any way cleaned electrodes ends and adjusted spark gap and also cleaned ceramic on electrode, fixed it and no more trouble (to date).

 

[Softus]

Thanks PVM - I shall try that tomorrow and report back.

I believe that the spark gap should be 3.5 +/- 0.5mm. Do you concur?

(I love Microns - they're just the best)

 

[PEDANTICVINDICTIVEMAN]

Says 3.6mm +/- 1.1mm according to 60ff service instructions, dont know what it is for others !

 

[Softus]

Thanks PVM - I'll bear that in mind and take the pragmatic option.

 

[Softus]

Latest news:

Went to check the spark gap, and found that there wasn't such a thing that could be reasonable measured, because there was only one electrode that sat only about 2 or 3mm above the crest of one of the burner bars.

Took off the electrode assembly, carefully cleaned the end, and refitted it - there was noticeable reduction in the rate of lockouts over the next couple of days.

Spoke to GW about this - a guy said that the boiler must be one of the latest models because the early ones all had double-pole electrodes. I knew this to be wrong because the appliance was installed quite some time ago.

Spoke to a parts supplier - a guy said that they only sold the double-pole ones. We were very both confused by this so I gave him the part number of the single pole edition - he checked with GW who told him that it was unavailable because it had been superceded by the double-pole part! This means that the GW guy that I spoke to was wrong.

Anyway, ordered the double-pole part, fitted it yesterday, and am now waiting to hear the outcome.

 

[PEDANTICVINDICTIVEMAN]

Thanks for the update, let us know how things go and if it fixes the probelm,
hope you didn't have to pay 50p per minute to be told wrong information, this is one of the reasons I wont fit glowworm products anymore.

 

[gasgeezer]

went to micron the other day similar symptons . The pump was not wired to the boiler i.e no pump over-run check that out. have changed o/heat stat on 50 microm which cured problem as well. lastly was there any fault codes.





[flashing lights on p.c.b] And is flue restrictor fitted, flue sound gas pressures o.k.

 

[Softus]

Thanks for the update, let us know how things go and if it fixes the probelm,
hope you didn't have to pay 50p per minute to be told wrong information, this is one of the reasons I wont fit glowworm products anymore.

Thanks PVM. And no, I didn't use the rip-off line, I used the wrong-information-service line. After this experience I will avoid Glowworm also.

went to micron the other day similar symptons . The pump was not wired to the boiler i.e no pump over-run check that out. have changed o/heat stat on 50 microm which cured problem as well. lastly was there any fault codes (flashing lights on p.c.b). And is flue restrictor fitted, flue sound gas pressures o.k.

Thanks gasgeezer. Thinking back all those weeks (!) to the original visit, I believe that I did check and the overrun was working as intended, but I will check again.

To answer your questions, the lights on the PCB were a steady reset LED and a 2Hz burner LED - according to the manual (and to Glowworm) this was a 'software fault'.

I haven't (yet) checked either for presence of the flue restrictor or the flue soundness.

 

[gasgeezer]

it is difficult to distinguish fast and slow flashing lights turn the gas off and wait for the lights ,ignition lock out is similar to soft-ware error i changed the wiring harness this cured a soft ware prob on a 50ff once before

 

[Softus]

Thanks gg.

Latest information hot (pun intended this time) from the customer is that the Micron has not locked out since the double-pole electrode was fitted, and that it has thereby posted a new "personal best" in length of time without locking out.

I may be tempting fate, but I now consider the problem solved, so thanks to everyone for the help and advice you've given me.

 

[Russell246]

Thanks gg.

Latest information hot (pun intended this time) from the customer is that the Micron has not locked out since the double-pole electrode was fitted, and that it has thereby posted a new "personal best" in length of time without locking out.

I may be tempting fate, but I now consider the problem solved, so thanks to everyone for the help and advice you've given me.

where can i buy one of these double poled electrodes? I'm not having much luck finding one; single poled: not a problem.

 

[NellieJ]

Having done some research on this fault with my Micron 70ff boiler I was tipped off that the ignition electrode has been modified to overcome this problem. The modified part has a twin electrode (part No 2000802541 and available from keeptheheaton.co.uk) whereas earlier models were single electrode. Correct spark gap is also important.

It worked for me so good luck.

Thanks gg.

Latest information hot (pun intended this time) from the customer is that the Micron has not locked out since the double-pole electrode was fitted, and that it has thereby posted a new "personal best" in length of time without locking out.

I may be tempting fate, but I now consider the problem solved, so thanks to everyone for the help and advice you've given me.

where can i buy one of these double poled electrodes? I'm not having much luck finding one; single poled: not a problem.