Furnace Expansion Tank Full Of Water

Hot water heating system expansion tank compression tank drain procedure to re charge lost air.

Furnace expansion tank full of water.

This article describes the steps in draining of a steel compression or expansion tank used on hot water system heating boilers hydronic heat. A description of how the old style expansion tank provides a cushion for expanding water in a hot water boiler system. The boiler expansion tank absorbs the expanding water by allowing the air in the expansion tank to compress this prevents the pressure. The expansion tank s purpose is to protect your house s hot water system from excessive pressure which can cause damage to fixtures your water heater lines and or fittings.

You can also check your expansion tank s pre charge pressure by knocking on the side of the tank with your knuckles to determine if it s full of air or water. A hot water expansion tank is a small metal tank usually 2 5 gallons that s installed just downstream of the cold water inlet valve that feeds your residential water heater. Tanks not equipped with a site glass need an airtrol fitting. An expansion tank is not found in steam boiler systems which create heat by circulating hot vapor rather than hot water through the pipes and radiators.

Ratio of air to water inside the steel expansion tank hot water boiler expansion tanks. Step 2 prepare boiler to drain expansion tank. Pre charge pressure that s too low may be indicated when the tank is full of water. Before you turn the power back on and fire up the boiler be sure the boiler is full of water and the heat lines are also full of water.

It has an air bleeder on the bottom. Draining water out of a waterlogged expansion tank is a common heating boiler service procedure used to replace a lost air charge. You may need to remove air. Steam boilers are simpler systems that lack several components found in hot water boiler systems such as the circulating pump expansion tank and regulators for water pressure and temperature.

If the tank is more than half full of water it is time to purge it. The hot water expansion tank is a two gallon tank that hangs off of your hot water system or your boiler. It is used to absorb excess water pressure. Located on the bottom of the expansion tank is a fitting.

When water is heated or a hot water faucet is turned off abruptly pressure builds from expanding water molecules. Air may also find its way via the heating water to other air bleeders or vents in the system. The ratio of water to the air inside the steel expansion tank is optimal at a 2 3rds water to 1 3 air. Low pressure can cause too much water from entering the tank.

This is important because water does not allow the correct pressure for the boiler to work properly.