BOILER
FF
EXPANSION
TANK
ZONE 1
ZONE 2
V1
PV4
FIGURE 2:
PREFERRED PIPING
FOR ZONE VALVES
ON BOILER SUPPLY
ZONE 1
V2
V3
ZONE 3
ZONE 2
V2
V3
ZONE 3
V2
V3
• AIR PURGING SEQUENCE
BY ZONE
LAST
FIRST
BOILER
FF
EXPANSION
TANK
ZONE
1
ZONE
2
V1
PV4
ALTERNATE PIPING
FOR ZONE VALVES
ON BOILER RETURN
ZONE 1
ZONE 2
V2
V2
V3
V3
ZONE
3
ZONE 3
V2
V3
• AIR PURGING
SEQUENCE
BY ZONE
LAST
FIRST
P
P
ZV3
ZV2
ZV1
M
ZV1
ZV2
ZV3
M
M
M
M
M
SUPPLY
∆
T SENSOR WIRING
RETURN
SUPPLY
∆
T SENSOR WIRING
RETURN
3
KEY:
VI, V2, V3 = SHUT-OFF ISOLATION VALVE
P = TACO CIRCULATOR WITHOUT IFC INSTALLED
FF = FAST FILL BOILER FEED VALVE
PV4 = PURGE VALVE
ZV = ZONE VALVE
RECOMMENDED PURGING STEPS:
1. CLOSE V1, PV4, V2
2. OPEN V3 AND ZV3
3. OPEN FF VALVE
4. OPEN V2, PV4, TO PURGE LAST ZONE
FIRST (ZONE 3)
5. CLOSE FF VALVE
6. CLOSE V2, PV4
7. REPEAT STEPS 1 TO 6 FOR EACH
ADDITIONAL ZONE, PURGE ZONE 1 LAST
8. OPEN V1 WHEN ALL ZONES ARE
PURGED
9. ADJUST SYSTEM TO DESIRED OPERATING
FILL PRESSURE IF REQUIRED
10. MOVE ALL ZV TO CLOSED/AUTOMATIC
POSITION
