Ferroli optimax 25 c heating won't come on

http://www.ferroli.co.uk/wp-content/uploads/downloads/2012/05/Optimax-25-C-Manual.pdf

Is there an error code? If not the flow sensor for the hot water could be faulty. Also if you've had a power cut depending which model of Optimax HE you have, you sometimes have to tell the boiler it's a Combi, as they have a generic Pcb fitted which is also used on the system only boilers.

Heat exchanger blocked or pump failed, the boiler is overheating internally.

I don't see why not, just keep a eye on it, and run it only when you are using it. shut it off when not in use !!! stay clear of the pop off valve when checking it !!

There is a parameter on the pcb to change would take 30seconds to do. Never replace ur pcb for these faults. Hold down reset untill u see t5 press reset 1 more time it will then say p01 press the heating temp button until u see p02 press the hot water temp button until it changes to numberv2 and that will fix ur problem

it is either your pump is not running or blocked [ debris from installation ect ] or your diverter valve is stuck partially open allowing a little water to pass into the heating system [ usually first rads on system ] it runs for a short while and cuts out because your overheat stat is kicking in because of poor circulation [ it is only running around the primarys in the boiler where it quickly reaches the over heat limit ] temp tends to rise approx 1 deg per second a clear indication of circulation problems.
solution GET RID OF THE FERROLI

try here..thank the finder
Optimax HE Digital Timer instructions

hi had same problem engineer came out and the diverter valve was cloged up sorted it and recomended a system flush plus install a magnet clean whitch picks up debri be 4 it gets 2 the boiler.

D2 is not a fault what that means is delay and 2 refers to CH which means the boiler has gone into standby mode. you need to check that your CH circut is open, there is a filter on the return valve into boiler make sure this is not blocked. If this is blocked the water is just going though the boiler by-pass so then the boiler thinks its up to temp. hope this helps

Here is a link to the manual.It shows fault codes.
http://www.ferroli.co.uk/Product_Documentation/Domestic/Optimax_HE_31_C_Manual.pdf

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