wrote in message
...
Update- son has just checked

the valves he has are two open shut valves (both appear to be working)
not y valves.

The thermostat downstairs seems to open and shut the valve but it
doesn't trigger the boiler and pump on.

The honeywell room thermostat in the lounge has 2 x 2 (2 larger wires
which contain a red and a black in each) be he can't see where these
should connect in the airing cupboard.

There should be a control terminal box in the locality of the valves where
the main interconnections are made. IIRC you said there was in an earlier
post.
Both Honeywell water and heating valves should be connected into this via
five wire flex.
Each valve will have a opening signal to its motor via a (usually brown)
wire and if the valve is opening then it must be present ok. Also each valve
will have a neutral (blue), an earth (green/yellow), a permanent live feed
for controlling the boiler and pump (grey) and a switched or controlled
signal wire (orange). The greys will be joined together and connected into
the live supply, the oranges will be connected together and joined to the
wire(s) feeding the pump and boiler. The valve heads contain microswitches
which close their contacts when the valve is fully open. The grey and orange
wires are simply connected to these.
With a suitable test instrument (and we don't need a clamour about not using
neon screwdrivers here thanks folks) check if the live feed is present to
the grey wire to the valve serving the heating and if it is, continue
checking to see if it arrives at the orange wires in the terminal box. Note
here that manually operating the valve with the trigger will not cause the
microswitch in the unit to operate so energise it via the programmer and
room thermostat.
I suspect from afar that you may have either a cocked up wiring scheme of
one of the wires described is not making contact somewhere along the route.
possibly one of the greys or oranges is broken off under a screw in the
terminal. Honeywell valves don't usually suffer from microswitch failure but
the same cannot be said about a lot of their competitors.
I come across a LOT of wiring centres/junction boxes which do not conform to
the industry standards but you may find it helpful to google for honeywell
or S-plan and have a look at a wiring diagram for how it should be wired