Hello,
Normal conditions, Boiler on, Thermo 19degrees, timer on.

Heating on, heating goes past 25 degrees with no control of timer or
themostat,
Hw always available and not as required and not contollable temp (ie on
the dial),
Cant get any controls to take control of boiler,
Constant ignition and boiler off, within 10 seconds of each other, this
is constant repetition,
Extraction fan is normally on 24/7, but since these ailments this
doesnt come on to cool boiler when boiler turns off?

any ideas?
thanks
Martin