Hi,
My Chaffateaux Britony 80 combi boiler has a recurring problem (as
mentioned in an earlier post). A Chaffateaux tekkie thinks its the
diverter valve. It's not easy to get detailed advice from him because
I'm not a registered engineeer.

I can see the diverter valve in the diagram in my user booklet. It's
part No.17 in the following illustration:

http://tinyurl.com/yx4ku9

I'm puzzled because there are no wires going to that component, apart
from the CH control thermistor wires. (No.16 in the pic).

So how do these 3-way valves work? Electrically, or by some other
means? What sort of fault could cause it to acasionally malfunction
for seveal days on end and then clear up for a few days?

Thank you,

Drake