Some basic central heating questions:

* Whats the difference between a "lockshield" valve and a thermostatic
control valve -- the ones with numbers 1 to 10, say, which you turn to
control individual radiator temp.

* Thermostatic control valves -- should they be turned clockwise to
reduce radiator temp, anti-clockwise to increase radiator temp? Is
there a standard direction in which they operate?

Bruce