Noticed a small leak from my Vitodens 200 system boiler today. It's coming from what appears to be a thermocouple (its a brass cylinder with a thin copper tube going to the PCB) in the water return. What does that do?
I've been online to spares places to try and find it - although not knowing what it's called doesn't help and I couldn't find any pics that matched up.
Have to try and find the paperwork tomorrow.