Boiler Manual
Part Number 550-110-593/1099 23
1Boiler isolation (balancing) valves
2Flow/check valve
3System or zone circulator
4System temperature gauges
5Zone valve
6Drain valve
7System temperature valves (see instructions to the left
for adjusting valves)
8Blend temperature gauge
9Relief valve
10 Automatic air vent (with diaphragm-type expansion
tank), or connect to tank fitting (closed-type
expansion tank). DO NOT use an automatic air vent
when using closed-type expansion tank. It would
allow air to leave the system, causing waterlogging
of the expansion tank.
11 Fill valve
12 Diaphragm-type or bladder-type expansion tank,
if used (For closed-type expansion tank, pipe from
top of air separator to tank fitting as in Figure 10.)
13 Air separator and automatic vent, if used (Note that
the fill valve must always be connected to the
expansion tank, regardless of location of expansion
tank, circulator or air separator.)
Boiler-bypass (alternate) piping —

for radiant heating or converted gravity systems

Figure 15 Boiler-bypass piping
Zoning with circulators
(Alternative to primary/secondary piping
Figures 13 and 14)
Figure 16 Boiler-bypass piping
Zoning with zone valves
(Alternative to primary/secondary piping
Figures 13 and 14)
59312
10
Cold
water
fill
11
12
9
ZONE 2
ZONE 1
1
11
1
2
2
4a 4b 3
66
7b
7a
8
13
GOLD
CGa
59313
10
Cold
water
fill
11
12
9
4a
8
3
4b
7a
7b
13
GOLD
CGa
Alternate
circulator
location
5
11
66
ZONE 2
ZONE 1