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MorrHeat - Most Heat In The Industry - Rev 3/18/2019
Filling Boiler
1. Fill boiler and system in accordance with job specification. System pressure should be set to
have 5 PSI pressure at the highest point in the heating system. Boiler pressure gauge will indicate
pressure relative to the height of water column from the boiler to the hightest point, plus the
additional 5 PSI.
Caution
The expansion tank must be properly sized to system requirements. An under-sized
expansion tank will cause system water to be lost through the relief valve and make-up water
to be introduced though the fill valve. Continual introduction of fresh water into the system
will cause mineral build-up in the boiler sections and eventual section failure.
Caution
Never purge system while boiler is in operation, also never run cold water into a
hot/empty boiler
2. Purge air from boiler and system.
Example - To calculate cold fill pressure:
Highest point in system above boiler is 40'; 40 + 2.31 = 17.32 (1 PSI = 2.31 Ft. W.C.)
Add 5 PSI to 17.32 = 22.32 PSI; boiler pressure gauge will indicate 22.32 PSI (cold fill pressure).
