Hi i have a pump from a cold water tank this is at first floor level, the cold tank in turn feeds the hot water system to three bathrooms and kitchen, you turn the hot water on and you can hear the pump working, all fine until the pump kept running for a few seconds, we turned it off at night so we were not disturbed by the noise. No obvious leak. there appears to be air in the system now, sometimes the hot tap in one bathroom will not work unless you turn another tap on. Any ideas?
