Glow worm flexicom 18hx how to fill water + no pressure gauge??!

[Sg_fletch]

Hi, hopefully somebody can help me with this. The boiler in our house is a glow worm flexicom 18hx but it doesn't seem to be heating the downstairs radiators even though they've all been bled. I'm putting this down to lack of pressure and that fault code comes up on the boiler if I turn the thermostat upstairs off and the one downstairs on full.

however, there is no pressure gauge I can see to check, and I can't work out where the tap is to let water in?
i have attached some photos to show the layout.
If anyone can help I'd really appreciate it as it seems it should be a fairly simple operation which I should be able to do myself.

thanks

 

[ShaunCorbs]

airing cupboard

 

[jonnyswamp]

It's a heat only boiler, open vented so won't have a built in pressure gauge
There will be a small tank in the attic (probably, but if not attic, somewhere above the highest radiator)
The problem you describe is either down to sludge or a failing lump, or a bit of both

 

[jtsplumbing]

This could be open vented system or sealed system, have you got a small red tank any where on system ? or tanks in loft ?

 

[jonnyswamp]

Looks like a combined feed/vent on the tee before the pump

 

[jtsplumbing]

Looks like a combined feed/vent on the tee before the pump

Yes you are more than likely correct ! But I never take it for granted, some people do strange things, maybe OP can come back and give us more information

 

[jonnyswamp]

Yeah I know what you mean

 

[Ruffellio]

Your system is working on an s plan call for hot water and make note of which zone valve opens then turn the call for hw off then call for up stairs heating make note of that zone valve then turn off then call for down stairs heating and make note of that zone valve then turn off.(turn each demand off as soon as the valve opens you can write on the valves hw chu chd or what ever you want) my guess is the zone valve has failed or only opening slightly and the flow hasn't got no where to go and causing the boiler to lock out due to the sudden increase in temperature.or you have an air lock down stairs which will be fun to get rid of but it can be done quickly and easily.