I got a Suprima boiler with Megaflo hot water tank. Heating and hot water are fine. Boiler has the new PCB. But the pump runs continuously except for 2 or 3 seconds every couple of minutes (boiler clicks in time with it going on and off). There's no frost stat.
The boiler also comes on at frequent intervals during the night when hot water and heating are timed off, for about half a minute each time.
Any ideas what's wrong?
