ariston eurocombi sx20 mffice?

My SX20 Ariston Eurocombi, red light keeps coming on when central heating is on, do the gas burners need cleaning? or is it another problem? Or does it need a new diaphram?
No hot water, heating has to be turned on to get hot water, phoned a few plumbers for a quote, just for a service and a certificate, priced at £45 service and £85 for a certificate, I was afraid to ask the price for the other problems. Please could you give me some figures (roughly) so I know what to pay. Thank you.

Neil
November 2009

yes your diaphragm in your divertor valve has failed and need changing

dave
June 2008

No answer but does anyone know where I can get a manual?

Gary
March 2008

Hi Aaron
I have the exact same problem with my boiler if you have found out the problem could you email me the answer simon.blanch@stockton.gov.uk That would be great if you could help, I have no manual and a plumber has no Idea. Please help.

Simon Blanch
January 2008