Ferroli Falcon Hot Water Problem

[simonrossi]

Thanks again. Will replace CH thermistor; check resistors on board and replace the overheat stat.

Is venturi plastic tube thing inside fan? If so entire fan was replaced about 1 month ago so i doubt that it's that.

Thanks again!

 

[solman]

changing to a brown venturi should do the trick but like modenas and dominas the heating sensor if coated in scale/sludge will send irregular resistance readings and interfere with hot water sounds crazy ive lost count the amount i have changed in my 5 yrs with ferroli

 

[simonrossi]

I'm going to assume that the Venturi is that small brown plastic thing that's part of the fan. It was replaced along with the fan 2 weeks ago.
I've now replaced safety overheat thermostat or the central heating flow limit thermostat and both the DHW and CH thermistors new fan and the DHW heat exchanger has been descaled. I'm still getting issues.
Usually when CH first comes on. CH demand light on and no ignition. Weirdly once the boiler gets warm it seems less of a problem.
Guess I'll have to get Ferroli in to have a look. I did look at PCB and it seems there is some brown discoloration near most resistors.
However I'm sure I need engineer to do this as it's not a simple swap and some calibration needed of the board once installed,
Thanks again everyone!