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4.4 Filling The Boiler
1
Fill the system with water. To be sure that the unit is not “air bound,” open the relief valve. Leave the valve open
until a steady flow of water is observed. Close valve and complete filling the system.
2
In hard water areas, water treatment should be used to reduce introduction of minerals into the system.
Excessive buildup of minerals in the heat exchanger can cause a non-warrantable failure.
3
Make sure there are no system leaks. DO NOT use petroleum based stop-leak products. All system leaks must
be repaired. The constant addition of make-up water to a closed loop boiler system can cause minerals to
collect in the heat exchanger. Excessive buildup of minerals in the heat exchanger can cause a non-warrantable
failure.
4
For systems requiring freeze protection, use only hydronic system antifreeze with a maximum concentration of
50%. Follow the glycol manufacturer’s instructions. DO NOT use undiluted or automotive type antifreeze.
