As per at @terryplumb. It will probably need a professional to troubleshoot.
I had hoped the test I suggested would result in the valve moving to its heating only position. A 3-Port valve relies on a 'hot water off' signal to close off the hot water port of the valve when hot water is not required, but the heating is still 'on'. This connection is definitely missing from Terminal 1 of your programmer....
.....and would also appear from the failure of the test to be missing from your cylinder thermostat as well. These connections would be the wires connected to the terminals shown in the black rings from the Cylinder Stat and Time Controller that are connected to the grey wire from the motorised valve.
There could of course be other faults, but this is where I would start. It could just be that someone has replaced 2 x 2-Port motorised valves that don't need a 'HW off' connection with one 3-Port motorised valve which does.
You say that you have just "moved house" by that I wonder if it is a rented property, if so, it's your landlord's responsibility to fix it.
I had hoped the test I suggested would result in the valve moving to its heating only position. A 3-Port valve relies on a 'hot water off' signal to close off the hot water port of the valve when hot water is not required, but the heating is still 'on'. This connection is definitely missing from Terminal 1 of your programmer....
.....and would also appear from the failure of the test to be missing from your cylinder thermostat as well. These connections would be the wires connected to the terminals shown in the black rings from the Cylinder Stat and Time Controller that are connected to the grey wire from the motorised valve.
There could of course be other faults, but this is where I would start. It could just be that someone has replaced 2 x 2-Port motorised valves that don't need a 'HW off' connection with one 3-Port motorised valve which does.
You say that you have just "moved house" by that I wonder if it is a rented property, if so, it's your landlord's responsibility to fix it.