Viessmann VITOCELL 300-H Installation Instructions Manual page 16

Connections
Domestic Water Connections
42 and 53 USG (160 and 200 L) capacity
92 and 119 USG (350 and 450 L) capacity
Legend
A Domestic hot water supply
B DHW recirculation line
C recirculation pump
D Spring loaded check valve
E Discharge pipe
F Pressure and temperature relief valve
G Shut-off valve
H Drain
16
(continued)
K Domestic cold water supply lines
L Back-flow preventer
M Domestic cold water inlet
N Precharged expansion tank
(required where back-flow
preventer is installed; check local
plumbing codes and requirements)
Vitocell 300-H, EHA Series Installation