9
LOW WATER
CUTOFF
BASKET TYPE
STRAINER
Sy
ste
m
Re
tur
n
MANUAL RESET
HI-LIMIT
SHUT-OFF
VALVE
RE
TU
RN
HE
AD
ER
SU
PP
LY
HE
AD
ER
AIR
SEPARATOR
CIRCULATOR
EXPANSION
TANK
PRESSURE
REDUCING
(FILL) VALVE
AIR ELIMINATOR
(AIR VENT)
FLOW CHECK
VALVE
BACKFLOW
PREVENTER
To Potable
Water
System
FIL
L
Sy
ste
m
Su
pp
ly
City
Water
Supply
T
Y
P
IC
A
L
P
IP
IN
G
F
O
R
S
P
A
C
E
H
E
A
T
IN
G
S
Y
S
T
E
M
FR
ON
T O
F B
OI
LE
R
MOUNT DRAIN VALVE BELOW
RETURN CONNECTION
RETURN
INLET
MAKE-UP
WATER METER
T
Y
P
IC
A
L
P
IP
IN
G
F
O
R
C
O
M
B
IN
A
T
IO
N
S
P
A
C
E
/V
O
L
U
M
E
W
A
T
E
R
H
E
A
T
IN
G
S
Y
S
T
E
M
NOTE: WHEN A HOLBY MIXING VALVE IS USED
THERE MUST BE A 27" DROP BELOW THE COIL
COLD WATER TERMINAL IN THE COLD WATER
LINE BEFORE ENTERING THE COIL
To Potable
Water
System
City
Water
Supply
MIXING
VALVE
LOW WATER
CUTOFF
HEAT EXCHANGER
MOTORIZED
VALVE
Se
rvi
ce
Ho
t W
ate
r
Su
pp
ly
Se
rvi
ce
Re
cir
cu
lat
ing
Ho
t W
ate
r
BRONZE
CIRCULATOR
*
*
BASKET TYPE
STRAINER
Sy
ste
m
Re
tur
n
SHUT-OFF
VALVE
MANUAL RESET HI-LIMIT
EXPANSION
TANK
AIR SEPARATOR
AIR ELIMINATOR (AIR VENT)
CIRCULATOR
FLOW CHECK VALVE
Su
pp
ly
FLOW CHECK VALVE
PRESSURE
REDUCING
(FILL) VALVE
FR
ON
T O
F B
OI
LE
R
MOUNT DRAIN VALVE BELOW
RETURN CONNECTION
RETURN
INLET
BACKFLOW
PREVENTER
MAKE-UP
WATER METER
TYPICAL PIPING FOR
SPACE HEATING SYSTEM
Figure 3.4
TYPICAL PIPING FOR
COMBINATION SPACE/VOLUME
WATER HEATING SYSTEM
Figure 3.5
