Worcester boiler pressure at 4 & radiator taking an hour to get warm?

It's at 4? And rests at 3 when the boiler's off? I'm amazed your PRV hasn't blown. Does the pressure eventually drop to zero?

That's waaay too high. Drain some out (bleed a rad or use the drain point on the boiler) til it drops to 1.5 when cold.

If the pressure creep back up, make sure the filling key is removed (or if you have a filling loop, disconnect it). If it still creeps up, you have a problem - most likely a pinholed plate heat exchanger is letting mains water into the CH system causing the pressure to rise.

BunSlinger
October 2008