I have a Feroli optimax he plus 38c boiler. I have replaced the room theromastat as the old one was the wrong type. The hotwater works but the heating does not work. I have turned the thermostat up to +25 and still no heat from the boiler. Can any help

grumpy old man 666, August 2010

my boiler stats up gives hot water lites the boiler then goes to d2 or d1 and just stays warm ???

tom arnold, March 2013

We have the same boiler and this happened to us last year. The engineer had to replace the valve as it had snapped! It is made out of plastic and he said it may snap again! Well, it has! I am typing this as I am on hold with Ferrolis customer service - I am not a happy customer!

Chloe, December 2010

does the pump operate when selecting central heating if so check the hot water feed from boiler and if this is getting hot without any hot taps in use then the divertion valve is stock in the hot water mode flush system and re pressurise boiler then try again if this does not fix problem then valve needs servicing/replacing

Astec87, September 2010

How was the old room thermostat 'the wrong type'?
Which thermostat have you fitted?
The connections required are voltage free.
It would depend on the new room thermostat you've fitted, check voltage from terminal 5 and with the clock and room thermostat on, the same voltage should return to terminal 6.

From the installation manual:
CAUTION: THE ROOM THERMOSTAT MUST HAVE VOLTAGE FREE CONTACTS. CONNECTING
230 V. TO THE TERMINALS OF THE TIME CLOCK AND ROOM THERMOSTAT WILL IRREPARABLY
DAMAGE THE P.C.B.

If you don't know, don't chance it.

Carefree, August 2010