Powermax 155x boiler lock-out

[MartJ]

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?

 

[Agile]

I dont really understand what you are trying to say! Its not clear if you have checked the system pressure or not. That is a user job and should be checked regularly. Its not likely to be associated with locking out.

As usual I presume this boiler has never been given its annual routine service!

This is one of the more difficult boilers even for a professional and I dont see what you could do beyond topping up the system presure.

My advice would be to get a professional to diagnose the problem. Make sure you quote the model to him first and its better to ensure he has a No fix-No fee charging policy as you dont want to be charged just to be told he has no idea what the problem is.

Tony Glazier

 

[weareleeds]

Biggest problem i have had is fan not runnung fast enough.That is how they start (locking out occasionally at first then getting worse until it won't work at all

 

[itjathome]

Is your mother in law in a hard water area? If so and the problem has been getting gradually worse it is likely that the system is well scaled up, i have been through hell and back with this same boiler and i am happy to share my experiences with you if it helps. if the central heating is ok and works efficiently then have a look at the hot water pump, this circulates hot water inside the thermal store i believe. This was the first problem with mine....the pump had failed, causing all of the heat to stay at the top of the boiler only and cause an overheat and subsequent lock out prematurely. This would be a good thing to check first.

 

[MartJ]

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.

Tony - Thanks for advice - I realise I wasn't clear. The problem is I cant even get at the link to re-pressurise.

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, not 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! All other comments welcome.

 

[itjathome]

top front panel simply slides up, no screws

 

[MartJ]

Thanks, itjathome.

The system worked fine on Boxing day and we were using lots of hot water and rads etc, so I don't think it's anything too drastic. However, if zero pressure isn't a cause of lock-out, then I shall get a specialist anyway. Mum has "had men in" who haven't got to the bottom of it, but perhaps she didn't explain properly either . . .

Any volunteers / recommendations around Princes Risborough?

 

[MartJ]

The link is not behind top panel which I got off OK. As all pipework is from floor, I presume the link is inside but lower down and I couldn't see how to get lower panel off.

 

[itjathome]

sorry just read properly. Remove two screws at the bottom of the panel, they are tucked just under the recess. Dont be too obsessed with pressure, it doesn't sound like it to me. Has it got a flow switch? check that when you turn on the hot tap.

 

[ChrisR]

weareleeds]

Biggest problem i have had is fan not running fast enough.That is how they start (locking out occasionally at first then getting worse until it won't work at all)

Can that be checked by measurement of the pressure in the air sense line? (MI say 4.8 - 5.5 mbar)