Hi everyone,

I've found some old threads on Glowworm Micron 50ffs which seem to suggest that my boiler was doomed from the start?

I've had an intermittant problem for a while with the lights showing a 'non-volatile' lockout and the boiler needing resetting.

Can anyone confirm that this actually means that my boiler has overheated and tripped out?

Are there common causes for this problem. I've read things about draining the system and possible pump problems?

The manual suggests that I should be checking the water system for overheating.... how should I do this?

Any help would be greatly appreciated

Matt, April 2008

My boiler keeps going off 5 to 10 minutes after restart. The reset light stays on while the boiler light flash, when l turn off and on the same happen, what should I do.
Franklin

Franklin, February 2019

Ignition sequence - fan running - air pressure switch proved - sparking at the electrode. If no ignition at the burner check for 240v to earth on black and brown of the gas valve solenoids (test at the pcb). If 240v present replace gas valve. If 240v not present replace the pcb.

Imperial Gas & Electrical, July 2015

been having the same prob with a 80ff micron, replaced, hi limit stat, and temp sensor, then pcb all to no avail. only thing left is maybe pump sticking at times. will post when i change the pump.

joe murray, December 2009

Ok i have the 60ff too thought i would share what happened to us, might help some people, We seem to have the water working fine with the boiler then as soon as the heating was turned on it would shut off, checked the pressure and it was very low, went to the y valve on top of the water pump(not on the boiler but up near the tank) and moved it manually via a small tag at the back of the silver box on top, switching this made the wall heater/water switch think it was heating the water but really its heating the house so it worked. i thought i needed a new pcb but no i need a new y valve, not enough umph to switch the valve, pcb was £130 so it would have been costly, still not sure why the boiler turns off when the y switch moves to heating, im guessing the boiler is not recieving the right signals from the honeywell wall switch and y valve. because it is getting stuck.

hope this helps someone took me 3hrs to figure this.lol

chris, November 2009

I have a Glowworm Micron 60ff, I replaced a downstairs radiator and when I switch the boiler back on it showed a non-volatile lockout. It turned out to be air trapped in the primary supply pipe after I had filled the radiator. My system was fitted with a makeshift air bleed valve at the highest point just above the bolier. Once I had bleed the air out of the system and reset the pressure the boiler fired up normally and is still working fine.

Roy, February 2009

I've been trying to fix our 40FF. The PCB was replaced a couple of years ago, then the thermistor went (last year). We've now got the non-volatile lock out! I've just replaced the Safety Temperature Limiter, but to no avail. All I can suggest now is that it's something to do with the pump or valves. The radiators are all bled and the water pressure's ok. Still scratching my head and searching the net for answers. Here's a link to the Micron 40FF manual: http://www.glow-wormorders.co.uk/manuals/pdf/Micron40FF.pdf

Anthony, December 2008

i have been having problems with micron 40 FF intermittently locking out had a new pcb board fitted in march. Lockout started again when began to use heating for the winter. British Gas came out 3 times and replaced 3 different parts but it was not solved glow worm recommended replacing the pcb board (despite having had one fitted in march) - b.gas did this and at same time fitted a capacitor -i know this because they left me the two information sheets.

sorry i am not a technical person so cant give a proper explanation but it has worked!

LB, December 2008

Not an answer, but I have exactly the same problem with a Micron 40FF - does anyone know why they do this, and what it means please?

Neil, September 2008