I have a c/h and hot water system with a large cold water large tank and a small c/h tank in the attic. It has a copper hot water cylinder at 1st floor and a Potterton Suprima boiler downstairs (indirect system??). Anyway, yesterday I drained the c/h system in order to remove 2 radiators. Later that evening the c/h came on while the c/h was still drained due to forgetting to turn the time clock off. Ever since then, if I turn the hot water on, the pump also comes on and makes a continuous loud grinding noise. I thought the pump was just for the c/h and the pump wouldnâ€™t come on for just the hot water â€“ is this correct?? Also, have I now wrecked the pump which may have been on for appx an hour and possibly running dry, or have I sucked air into the system making the noise which needs to be bled off.
Any assistance is appreciated, as I my knowledge of c/h is limited.