Check that there are no dripping taps or leaks of any kind on
the hot water pipes. Check no joints, isolating valves, washing
machine taps etc leaking (hot supply).
There is no one on this forum that can help you with your heating problem.
You should get yourself to your local Citizen Advice Bureau.
(It may be Help Shop now)
They will sort you out with the proper legal advice.
Hope you will get it sorted soon.
It's a pretty good bet that the receiver is knackered.
Test the output with a meter when the green light is on.
Drayton are not among the better RF stats.
Check the boiler thermostat (r/h side under the cover)
Make sure it is not on zero. turn it up & down, does it click?
If not it could be the problem
You cannot do much more under the cover.
With the control panel lowered you can see the bottom inch or so
of the vessel. It's the red bit you can see at the very back.
The charging valve is at the very top of the boiler.
Hacksaw blade in a pad saw handle or rag wrapped around
for comfort.
2 or 3 cuts across the threads then prise out with a screwdriver
or small chisel. Does not take long.