I am really having problems with it as i don't get hot water for more than 3 minutes and sometimes it doesn't heat up.

Dee, August 2009

never heard of ER, are you sure it's not EA?
if it's EA it's a flame detection problem, i.e. the burner has not ignited or the flame has not been detected by the pcb. try re-setting the boiler, otherwise have a qualified engineer take a look at it.

Ian, August 2009