Powermax 155x boiler lock-out

[MartJJ]

My mother-in-law's Powermax 155x boiler is locking out sometimes several times per day. She says the problem has been getting worse for ages. Switching off and on again cures it. She has no manual. It was installed when the house was built about 3 years ago.

I know a little about combi-boilers - enough to know that the pressure should not be at 0 bar (the red arrow is at 1 bar) and I can recognise a re-pressure link and valve and use it with care. I also know that if this hunch is wrong, I'll have to get a specialist - I'll stick to bleeding my rads and changing washers.. But - as it is at the back of a cupboard I can't see how to get the front off!! The top panel lifts out OK, but I can;t see what to do next.

Can anyone help with either - how to get in - or whether my hunch is worth a try?

[ath007]

Had a similar problem with my worcester bosch going into lockout- once a week at the start then finally two or three times a day. Called a friend who works for BG,he came and adjusted the gas valve to give a bigger gas injection upon ignition. What can also happen is that the burner gets dirty and the ignited gas(of which there is not enough) is inhibited from reaching the electronic sensor at the back of the burner. I would not recommend messing with the gas end of things and would advise seeking a qualified gas/ heating engineer on this one.

[stanleyman]

The pressure should be around one bar cold. You shouldn't need to remove the cover to repressurise as this loop is usually underneath a wall mounted gas combi but can be anywhere. Boilers are designed to fail safe and should be serviced annually to avoid problems

[grahamfreer]

I have answered this on diynot.com

[MartJJ]

Thanks all. I'm not touching anything gassy, so it sounds like a job for a specialist anyway, and a regular contract sounds a good idea.

It's a floor standing model and all pipework is under floor - very neat but not helpful for re-pressurising! So I assume the link is within the cover, no under the floor. Unfortunately, she doesn't live close enough for me to meet the specialist, so I'd still like to know how to re-pressurise when I visit her - I get the impression this may need to be done every few months (I have an old very conventional boiler so don't have these problems!).

So I'd still be grateful to know - how you get the front panel off!

[stanleyman]

This isn't a very common boiler and I thought it might be floor standing but the filling loop can still be anywhere. The front cover will either just lift up to remove or may have pins and clips in which case you have to pull it towards you, try a corner at a time, or maybe it is secured with concealed screws. If it loses pressure over less than say six months then there may be a leak that needs fixing.