Central Heating system reaching temperature & shutting down

[test electrical]

Am with the last plumber you should have powered up the valve both ways and seen if the the switch made turned the pump on and a tip is to disconnected the feed in the boiler to the controller pcb so your not turning the boiler off and on. You can tell if the water getting around the system as well. Let you know that the DHW is going round the tank and not the rads. Also make sure the earth isn't used as a live conductor, I've been to loads of these that have been wired up wrong.

 

[Startinez]

So I was looking through a picture that I took of the connector blocks and noticed that a neutral looks like it's dropped out of the three-way connection along with the supply neutral & boiler/pump neutral.

This makes sense to me as when the H/W is active, the pump is a closed circuit and therefore the cyl stat has a neutral path. When the water reaches temperature, the pump shuts off and the heating loses its neutral path.

I'm going to take another look over the weekend, but figured this actually makes a lot of sense given the scenario.

 

[Startinez]

So I was looking through a picture that I took of the connector blocks and noticed that a neutral looks like it's dropped out of the three-way connection along with the supply neutral & boiler/pump neutral.

This makes sense to me as when the H/W is active, the pump is a closed circuit and therefore the cyl stat has a neutral path. When the water reaches temperature, the pump shuts off and the heating loses its neutral path.

I'm going to take another look over the weekend, but figured this actually makes a lot of sense given the scenario.

 

[Last plumber]

So I was looking through a picture that I took of the connector blocks and noticed that a neutral looks like it's dropped out of the three-way connection along with the supply neutral & boiler/pump neutral.

This makes sense to me as when the H/W is active, the pump is a closed circuit and therefore the cyl stat has a neutral path. When the water reaches temperature, the pump shuts off and the heating loses its neutral path.

I'm going to take another look over the weekend, but figured this actually makes a lot of sense given the scenario.

You've looked at that wrong, unless it's wired wrong !
There should be no switched neutrals ( unless I've misunderstood your point) ?
If you look at the wiring diagram I mentioned before, you'll see how it's meant to be. The only difference should be that the pump should be wired from the boiler, due to the pump over run. ( if boiler needs one and most modern ones do).