Biasi 24S - DHW works but CH doesn't

[PaulY99]

My Biasi 24S works fine for DHW when the selector switch is set to the "Summer" position. However, when the switch is moved to the "Winter" position (ie both DHW and CH), the green light (power on?) doesn't come on and nothing works, with no DHW or CH.

The fact that the green light is out seems to point to a switch problem from looking at the Biasi manuals, but maybe someone here knows what may cause this?

 

[Agile]

The switch on the PCB has failed.

It may be possible to get it to recontact by rapidly rocking it from side to side.

The only official solution is a replacement PCB costing about £100.

For anyone with a very little electronics knowledge its easy to bridge the faulty contacts across the switch.

I did that once to get the heating working for tenants. Not because I did not have a spare PCB but because I could not trust the landlord to pay for a new one. There are so many dodgey landlords in London that I have to ask for payment up front.

Tony

 

[PaulY99]

Tony,

Thanks. Kinda what I thought when I looked through the manuals. While only an amateur plumber, I am experienced at electronics and suchlike, so will take a look at the switch/PCB.

Paul

 

[PaulY99]

Ok, fixed it. One of the common-pole connections on the selector switch had a bad solder joint on the PCB. The switch checked out Ok on the multimeter, so I re-soldered the joint and all is now working Ok.

 

[Agile]

You are really lucky with that!

There is no alternative replacement available and the original is not available except by factory order for a large minimum.

They are not very robustly made and if not switched every few weeks they arc and melt the plastic body.

Of course they can be linked across as a bodge repair but we are not expected to do that so its new PCB time.

Tony