Hardy C3, Installation And Operating Instructions Manual, Page: 31 / 66

HARDY MANUFACTURING CO., INC (MODEL C3 & C5) PAGE 17
3-3 Connecting to Existing Hydronic Systems
The preferred method for connecting the Hardy heater to an existing Hydronic system
is by installing a p/n 300.01- 40 plate heat exchanger w/ 1” fittings into the return line of
the existing boiler system. This will allow the existing boiler to remain a pressurized
system. This can be done by installing a shutoff valve and two bypass lines in the
heating systems return line. Install service valves into each of the bypass lines. (Refer
to Plumbing diagram below.)
Run two -1” hot water lines ( suitable for continuous flow ) from the pump and return of
the heater to the existing boiler system. Connect these lines to the plate heat
exchanger so that the water flow of the heater is opposite of that from the boiler
system. Bypass the relay on the pump to allow the pump on the heater to run
continuous.
Water pipes must be designed for hot water service (ex. copper, cpvc, or Pex.)
Pipes should be installed in a 4” watertight pipe or some other type of insulating
means to prevent heat loss from heater to heating system. Use only copper,
brass, or stainless steel fittings. Do not use galvanized or black iron.
Existing
Boiler
Heat
Zone
Heat
Zone
Existing
Pump
Heat Exchanger
Close this valve
Heater with Hull and stacks
removed to show connections.
Hardy
P/N 300.01
40 Plate Heat
Exchanger
with 1" fittings