Capacitor replaced, second time since 2008, but the problem remains?

Hi Dave, took me a bit longer than 4 mins to replace my Drayton Digistat SCR capacitor but I have done it (no solder sucker makes cleaning solder from the holes difficult - any tips there?) I put the SCR back and reset the system so that the thermostat should have been calling. Red light came on to start with, then the green light but no click hence no boiler start up. Any other ideas or should I adjust it with a club hammer and get a new one?! I have already replaced the batteries in the thermostat do I need to reintroduce both units to each other?