Worcester 24CDi - 3.5 bar pressure when not in use....?

Hi,

My mums boiler is a worcester 24CDi and for some reason when not in use the pressure goes up to 3.5 Bar. When in use it usually drops or sometimes the pressure just drops off over night or over a few hours.

At the weekend I tested it. When not in use it started at 1 bar. I turned on a hot tap and the central heating. The pressure got up to about 1.5 bar in 20 mins or so which seemed pretty normal to me so I switched the central heating off and the hot water. A few hours after I had left mum was back on the phone saying the boiler was at 3.5 bar again.

I have checked the water inlet valve which seemed ok as it can only let water in the system when the small white T clamp is in place, which isnt at the moment, and it does let water through when opened and stops when shut off.

Seems a bit odd to me, can anyone help? She has had several people attempt to fix it with no luck so far.

Thanks

Ben

For some reason the plate heat exchanger on your model is prone to leaking from the mains water to the system water.

Its a bit of a palava to change.

Tony

Thanks.

So is it a case of just change the seals/o-rings or a new heat exchanger? I think a plumber did 'fix' the leak before but obviously not good enough.

Thanks for your help

Ben

The seals could always leak and may have been bodged without replacing them by your "plumber". Those would normally leak to the outside rather than cross linking the water and heating.

All those I have encountered have been caused by internal leaks inside the plate HE itself.

Tony

Its a bit of a palava to change.

Click to expand...

Are you on the right one Tony.

Its one of the easiest to do.

As I recall there is a fiddly series of little plastic bits in front which comprise the filling loop which have to be carefully removed in sequence.

Of course "one of the simplest" may be comparitive with that dreadful Worcester with the diverter across the back which is a real pig to change.

Tony

Agile said:

As I recall there is a fiddly series of little plastic bits in front which comprise the filling loop which have to be carefully removed in sequence.

Click to expand...

No; it's the other way around - you have to remove the heat exchanger to replace the charging link.