27
MorrHeat - Most Heat In The Industry - Rev 3/18/2019
1. Close manual air vents (if used) and automatic air vents. Attach the hose to boiler drain on return
connection and run to drain or to outdoors. Open drain cock and close shutoff valve on the boiler
supply pipe.
2. HEATING ONLY - SINGLE ZONE SYSTEME ---
Open manual valve in cold water feed line and set the fill valve to fast fill. Allow water to flow through
the system and out the hose until there is a steady flow of water through the hose with no air bubbles.
Next, open the shutoff valve in the drain until air bubbles cease. Then take the fill valve off fast fill,
close the drain cock, remove the hose and open all automatic air vents. Also, open all manual air
vents one at a time and close when water squirts out. Observe the temperature/pressure gauge.
System pressure with a cold fill should be in the 12 to 14 psi range.
3. MULTI-ZONE SYSTEMS-HEATING ONLY OR HEAT & DOMESTIC HOT WATER WITH ZONE VALVES ---
To ensure good circulation through all zones with no air pockets, each zone should be purged of air
individually. With all zone valves in the manual open position let water flow through the system by
opening the drain cocks so water can exit the system through a hose an in 1. above.
When the system seems to be full and free of air, close the drain cock, and the shutoff valve on the
boiler supply pipe, leaving the manual valve on the cold water feed open. Now release the manual
openers to close all but one zone valve. Open the drain cock and put the fill valve on fast fill. When
the flow through those becomes steady with no air bubbles, take the fill valve off fast fill and then
close the drain cock. Repeat this procedure with each zone until all zones have been purged. Open
the shutoff valve on the boiler supply pope. Then open all manual air vents one at a time. When water
sprays out of the air vents should have the cap loosened so it can vent air.
4. MULTI-ZONE SYSTEMS ZONED WITH CIRCULATORS ---
Following the same procedure as in 3, above using the manual shutoff valves to isolate a zone
instead of zone valves.
5. Check system pressure on the temperature/pressure gauge on the boiler. Pressure should be in
the 12 to 14 psi range. If the pressure is over 14 psi drain a little water out with the drain cock. Watch
gauge for a few minutes to ensure pressure does not build back up. If the pressure is too high with
Boiler Start-up & Adustments
