kingtr
New Member
Hi. I have a six month old Navien NCB-240-130H combi-boiler with two Honeywell V8043 zone valves. The unit replaced an old boiler and water tank in my 1976 home which has all copper radiant baseboard heat. About a month after installation I started noticing what seemed to be air sounds in one zone. With time the sounds are in both zones, the first one is worse. Both zones now seem to have intense water hammer which seems to be associated either with opening or closing of the zone vales - I'm not sure which. There don't seem to be any error codes. Any ideas on how to repair the situation?