Main Eco Elite no CH but HW OK

[JohnD]

I'm afraid I'm not getting your point?

I think the OP does not have a tester.

Some thermostats have a Neutral wire. It will be connected if there is an accelerator. In the one shown, it is most likely the blue wire

If a neutral is present, it must not be connected to the others.

 

[RandomGrinch]

I think the OP does not have a tester.

Some thermostats have a Neutral wire. It will be connected if there is an accelerator. In the one shown, it is most likely the blue wire

If a neutral is present, it must not be connected to the others.

Yes, agreed.

There is a difference of interpretation of 'switch wires' - which were intended to mean the live and switched live - the wires that are actually 'switched'.

Whereas as you suggest, the 'switch wires' could also be interpreted as the entire cable going to the thermostat?

Sometimes we need to be careful with our language. I knew what was meant, but others may not.

Whatever the interpretation, the OP should hopefully soon know if their stat is at fault, or if it's something else....

 

[Mark13]

I'm still not electrocuted also put some insulation on those not used wires. Thanks for all replies.
Quite strange but the boiler started working again yesterday evening. Before it "fixed itself" I tried shorting y+r but it did not help. Then I also noticed that the hot water demand light was constantly ON even though all taps were off (no leaks). The hall sensor issue?
Anyway it's fine now, when have more time I will check the box next to the boiler to which the thermostat cables go, maybe some loose connection or something. I have a multimeter and basic knowledge how to use it btw. Hopefully the issue wont come back. Cheers.