Biasi Garda model M90F.28S

[JHW]

Hi folks, can anyone help with this problem?
Our boiler Biasi Garda model M90F.28S Only gives hot water when the central heating is on.
We had a service man fix the water flow sensor 3 weeks ago and it worked fine for 2 days.
Can't get hold of him now and he said he wasn't used to working with biasi boilers.

 

[Agile]

If what you say is correct then it does not seem logical to me unless he has bodged something.

Mostly for the others, the plate HE is only put into the system flow by the diverter valve motor AFTER a demand for DHW has been received.

In that case I dont see that having CH on will make any difference.

However, two simple checks are is the red light on the DHW demand switch illuminating with a tap on? Are the resistances of the two NTC sensors correct? Should each be about 12k when at room temperature.

If those are all correct then I would be checking that the diverter valve motor is operating correctly. ( Not just operating !!! ).

Tony

 

[JHW]

Hi Tony, thanks for your reply.
The only light on when a tap is turned on is the green light, which flashes all the time anyway. I don't have the skills to check resistances etc. The manual mentions gradual loss of hot water over time as a consequence of the flow switch filter needing cleaned (done) or limescale in the heat exchanger- since we have very soft water, I guess maybe the flow switch filter wasn't replaced properly as you said. I'll just have to get it serviced again.
Ta, JHW[/i]