Hello I want to wire my Room Stat which is a HorstmannDRT1 to the Honeywell 10 way Junction box, the problem I face is that the Horstmann has only 2 wires and the Honeywell has got 4 positions for the Room Stat any chance that you know the answer to my problem please Regards Roger

If in any doubt, get an electrician or heating engineer to connect it as there is full mains voltage on these connections.
The thermostat will have 3 possible connections. You need the NO and COMM. Ignore the NC.
If the 10 way junction box has four connections, these will be NO, NC, COMM and Earth.
You need to identify the NO and COMM in the junction box and connect them to the corresponding NO and COMM on the thermostat. The DR1 is double insulated so doesnt need to be earthed.
Please make sure youre absolutely certain that you have identified the correct terminals in the junction box - whilst electrically performing the same function, there are many ways to wire up the junction box.
Again, if in any doubt call in an electrician or heating engineer.