Problem solved. Invensys technical department very helpful. Fault was with connections in junction box. Using a Y plan wiring diagram discovered that live and demand were reversed. Corrected the fault and new stat works fine.
Hi. I have replaced an old mechanical stat (Tower Flue Components type DT) with a Drayton RTS1 but doesn't work. Three connections + earth on old stat are called "break on temperature rise", "common" and "spare" (marked N). Have connected to RTS1 as demand, common and n...