Biasi s combi boiler

[trollydolly]

My boiler does not produce hot water anymore when the heating is off, & only provides about 30 secs of hot water when the heat is on then it starts to run cold!

 

[Mikeyboy]

Sounds like knackered diverter valve.

 

[trollydolly]

What would be a reasonable quote to repair a knackered diverter valve on a Biasi s combi?

 

[Agile]

In the London area we would charge £106 inc. but this includes a proper service and performance check of the boiler.

In the Midlands its £96.

Tony

 

[ChrisR]

Diverter valve area, ok, but there's a flow switch to detect water flow, which chats to the electronics, which makes a motorised actuator to operate the diverter, so there's a few things it could be.

 

[Agile]

Chris, you are talking about the later M90 model where the DHW flow is sensed by a magnetic shuttle and Hall effect sensor.

This fellow has got the earlier 24S model with a hydraulically operated diverter valve.

Tony

 

[ChrisR]

Fair enough. Might help if they didn't put "24S" on them all!

 

[damon]

Hi guys, before changing diverter valve, would it be worth checking the dhw diaphram for splits etc. the 30 secs of hot water is probably being generated from the heat from the central heating; in addition to this there is a dhw thermistor, this will be a nominal resistance that will change according to temperature, if this is faulty it will not allow the burner to fire. Worth checking as you will get change out of £20 for both items.

Regards Damon.

 

[Agile]

If the NTC is open circuit, the usual failure mode, this model will fire up at full power.

The only fault mode which could prevent firing up would be if the NTC was very low resistance. This would normally only be caused by a leak with the leaked water bridging the connections.

Tony