I don’t like to interfere with for sale posts, but in this case I will make an exception.
The boiler over filling was an issue due to I think electrical interference . in the early models e.g. 2019, the Gicar box autofill probe has a wire to the probe and a wire (black) that needs to be grounded. They did this on the boiler and not the frame. The electrical interreference meant it sometimes overheated. That wire was later moved to a grounding on the frame and the problem went away.
The overheating will almost certainly be a temperature sensor requiring replacement
So it probably needs just a temperature sensor and the earthing wire moved to the frame. At absolute worst, it could be a faulty Gicar Box where one of the triacs has failed closed…it all depends on how it overheats.. Even at the very worst the parts can be ordered directly from ACS and the machine fixed for probably less than £140.
At best the cost to repair will be £30….so I would reconsider selling it.
That machine has another 20 years left in it!!
