Boiler Manual
Part Number 550-110-593/1099 21
Primary/secondary (preferred) piping —

for radiant heating or converted gravity systems

1Boiler isolation (balancing) valves
2Flow/check valve
3System or zone circulator (circulator should cycle
with zone valve and switches, using circulator valve
or zone control panel)
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.)
Figure 13
Zoning with circulators
Figure 14
Zoning with zone valves
59310
10
GOLD
CGa
ZONE 2
ZONE 1
1
1
1
13
1
2
2
4a 4b 3
66
7b
7a
8
12"
MAX.
Cold
water
fill
11
12
9
Alternate
circulator
location
59311
10
Cold
water
fill
11
12
9
GOLD
CGa
ZONE 2
ZONE 1
12"
MAX.
1
1
1
1
5
4a 4b
3
66
8
7b 13
7a
Alternate
circulator
location