Alpha CB24 not working

[cecilia]

Alpha CB24 not working, no hot water or heat.
When I switch the boiler on it makes all the correct noises and the green light flashes, but not hot water.
When I turn dial to water and heat again it makes all the correct noises but no water or heat.
I have noticed that the water pressure needs topping up about every two weeks. Any advise? Thank-you.

 

[mga]

dumb question: gas on?

 

[cecilia]

dumb question: gas on?

Thank-you for your reply, sorry about delay in answering, as meter outside I had to wait until some-one checked it for me. I was told that the gas was switched on.