Ferroli 32c He no hot water

[Jam85]

Ferroli 32c he (combi)

So after having a 2 week holiday, we have come home to no hot water.
It just cycles on off every second.

Heating working fine and have to use it for the water to be hot.

No fault codes.
Clicking noise in the pcb on trying for hot water?

Things I have checked.

Diverter valve....doesn't have one apprently
Flows in and out all good nothing blocked.

I know this boiler has a bad reputation but it was recently serviced with flying colours.
Just screams to me something is blocked but then surely no water flow.

 

[Deleted member 120897]

Sounds like a sensor imo if you’ve had nothing else done and the service passed.

 

[Jam85]

I've tested the flow meter.

12v between black and red
5v black and green(signal wire) no hot taps on.

Exact same readings with the hot tap on.
Now I'd expect to see 0V when there is no demand ?

 

[Deleted member 120897]

5v might just be from pcb.

 

[Jam85]

So you think it still could be the flow sensor ?

 

[Jam85]

New flow sensor and we now have hot water.