Will a pressure-balancing valve feed cold water to the hot water side when the hot water side is open? I had my water heater disconnected this weekend, with water off at the main supply. When I reconnected the water heater, I had the cold supply valve closed when I opened the main supply valve. Went to the water heater to open it's supply valve, and could hear water rushing in, with the valve closed??? Went inside to check a faucet and sure enough, I had cold water at full pressure on both the hot and cold side -- while the supply valve was still closed at the water heater.

I was told this was because of a pressure-balancing valve. Is this normal function for a pressure-balancing valve, or is there something else going on? I've only got one mixer valve (tub/shower) in the house - everything else is two-handled faucets.