Alpha cb25 pressure drop problem

10 Dec 2007
Reaction score
United Kingdom

We are having a problem with our Alpha hecb25 boiler.

It seems to work fine untill we turn up the central heating thermostat on the actuall boiler (to make the radiators hotter)

When we do this the pressure drops and the low pressure warning light comes on. to fix this we allow more water into the CH circuit using the one valve from the mains to top it up

to only way to prevent a pressure loss it to leave the thermostat on number 4. anything above seems to create a pressure loss.

Can anyone help?

A plumber has been round and checked for pipe work leaks (inside, round the radiator valves and joints etc.)

Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links