I have a two zone hydronic heating system. I changed out the pump and and purged the lines. On the 1st zone I purged the zone and pressurized they line to 15 psi. On the 2nd zone (upstairs), I opened the drain valve and no water came out. I added water until about 20psi and stopped. I turned on the heat anyway and had the 2nd zone call for heat. All the radiators were heating but when I opened the drain valve water was emptying. After a few days the psi on the boiler dropped to zero again. I can't find any leaks.
Why is there heat in the pipes but I can't detect any pressure using an external gauge or purge the line?
When the boiler pressure drops to zero could my boiler have a crack?
Why is there heat in the pipes but I can't detect any pressure using an external gauge or purge the line?
When the boiler pressure drops to zero could my boiler have a crack?
