Worcester 24cdi problem - sometimes the boiler doesn't work

[MarkDavies]

I have a Worcester 24cdi boiler, and it sometimes does not heat the water (neither central heating nor hot water). However, if I turn the hot water tap on, I can hear the water pump in the boiler working - it's just that the heater in the boiler doesn't engage (as confirmed by the heater indicator not lighting up).

I wonder if this has anything to do with the water pressure in the system, which is 0.75 bar at rest...

Does anyone know what the likely causes of this problem are? Is it probably low water pressure? Sorry, but I am a bit 'green' to plumbing...

I have been reading around this web site about how to top up the water pressure, but don't have a key (or even a manual) for the boiler (as some topics have mentioned). In fact, I can't see anywhere on the boiler to use a key.

Any help would be mucho appreciated!

 

[ollski]

Are you sure its the pump which is firing up and not the fan?....cdi air pressure switches are pretty prone to failure or it may just need a good clean, has it had a recent service?

 

[chrishutt]

To top your pressure up, you need to find a filling loop under the boiler, although CDIs usually have a built in filling mechanism for which you require a special key. Contact Worcester for that and the manual.

It could be that the low water pressure switch has operated, which would stop anything operating. I suspect the noise is just the water running through the boiler when you open a hot tap.

 

[jiminblack]

There's no low water pressure switch on the cdi. It could also be the pressure switch hoses at the fan end. They are prone to going brittle and splitting.

 

[MarkDavies]

Thank you folks. I will pass this on to my landlord.