Also the radiaters seem to be warm even if the thermostat is set below
the temperature of the room in which it is in, I can turn the
temperature down on room thermastat and the radiaters will still stay
warm.

Sounds like it could be the zone valve. It seems not to respond to either
the water requirement or the heating requirement from the stat.

The zone valve is the box with Honeywell F4-9348 on it. You can normally
take the plastic box part off without having to disturb the pipework part of
the valve. Provided the valve part itself rotates without much force, just
put a new box on it. (It's called the actuator).

In the mean time, move the switch from "Auto" to the other setting "Both",
"Manual", "Open" or whatever it describes itself as.

The switch that gets one tank of hot water could be for the electric
immersion heater. Where do the cables from the switch go? Does turning it on
cause your electric meter to go ballistic?

Christian.