I have a glow work economy plus 60B boiler with just the standard built in thermostat controlled on the bottom left with a dial. How easy would it be to wire up an external thermostat that could be wired through to another room?? Is there a connection to run off somewhere?? Very inefficient at the moment. Heating and hot water all combined in the system, all or nothing, is it a big job usually to have the option to heat the water and the heating separately? Any guidance appreciated.