Glowworm Micron 60ff - Non Volatile Lockout

[keepo]

Hi - Can you help? I have a Glowworm Micron FF60 Boiler and it has gone into "Non Volatile Lockout" - Reset light is solid green, boiler and everything restarts after turning off the temp dial and back on again. The fans work, it produces heated water, the pump is spinning (albeit its pretty quiet). After a couple of minutes the boiler switches off again. Its a conventional boiler not a combi. Just before it switches off you can hear the boiler sounds like a kettle warming up, as if the water is being heated but not going anywhere - not especially noisily but I don't recall hearing those noises before (its in an outside cupboard so I'm not completely familiar with its noises, but this is predictable its getting too hot). For the brief few minutes it is on, the rads start to get warm (I have not checked upstairs rads only downstairs thinking about it).

So, in essence, everything works when its working - what could cause lack of flow and should boiler make kettle type noises - I assume the temp thermostat is tripping out the system, but is it because it is too hot or because its faulty? The boiler will turn back on immediately if you reset immediately

 

[Agile]

M question relates to the boiler temperature control setting!

 

[keepo]

Thanks - Could you elaborate a bit please (I haven't moved any settings prior to this happening, although the variable knob does turn off the boiler ok). Also, this has happened from working perfectly, to not working in a single day - it has not been a gradual process

 

[ianmcd]

do you have a sealed system or an open vent system, your boiler is getting too hot could simply be low water pressure, post pics of your HW cylinder and everything else in that cupboard (to do with the heating) only Agile will be interested in pics of the other stuff

 

[keepo]

It has a little tank in the loft to keep it topped up. Heres a pic (and I left a little something for your mate Agile...)

 

[ianmcd]

Ha Ha love it, the little tank is an F&E tank check that there is water in it, try and bleed an upstairs radiator if the waer comes out freely , then the lack of water isnt the problem, if it doesnt flow freely then that is your problem

 

[keepo]

Ok tried that now - Water flows freely from upstairs radiators. I've just taken a video of it along with a (cheapo) temperature gun on all the pipework around the boiler. I'll try and get it on Youtube and post a link. This time I told system to only feed radiators (to exclude the hot water side) but it made no difference. It took 6 mins to shut itself off to Non Volatile stage.

 

[keepo]

Made a vid - here is the link

 

[keepo]

Ha Ha love it, the little tank is an F&E tank check that there is water in it, try and bleed an upstairs radiator if the waer comes out freely , then the lack of water isnt the problem, if it doesnt flow freely then that is your problem

just discovered that the pumped flow pipe is cooler than the return flow pipe, by quite a bit? Is that significant, I'd have expected the reverse of course

 

[keepo]

It is very much hotter, it gets hot as soon as boiler starts up and too hot to hold quite quickly. The pump and pumped feed I can hold all day long. I have an air vent above each of the Feed and Return pipes, I've opened both separate and let water bleed through for a few minutes each. Still got the same problem, boiler cutting out on overheat.....

 

[ianmcd]

sounds like your pump has seized

 

[keepo]

sounds like your pump has seized

Thanks Ian - but when I remove the vent plug and jam in a screwdriver I can stop the pump, but it takes some effort

 

[ianmcd]

Pump sounds Ok then, return getting hot first is a classic sign of a jammed pump, try turning the boiler thermostat down to minimum and see what happens

 

[keepo]

Was suggested on another site to check the pump direction - AND The motor was indeed on the wrong way around. Its been like that since 2018 but has obviously got by - I just went out and swapped it round (wasn't a difficult job and no wiring as just needed to tumble it over). Now either I've just created my own powerclean in reverse or whatever accumulated has been sent back from whence it came. All fixed - Thank you everyone for assistance