Secondary Return Design (Dhw Circulation Pump) - andrews MAXXflo EVO Installation And Maintenance Manual

4.5 SECONDARY RETURN DESIGN (DHW CIRCULATION PUMP)

A Secondary Return circuit may be fi tted to the 1" nipple at the top of the heater. In all cases, for serviceability,
the recirculation pipe must be fi tted with a stop valve immediately before the connection point.
See Section 3.6 Example 1 for wiring details
If a secondary return circuit is fi tted with a secondary pump, please ensure that the fl ow-rate does not exceed
the heater maximum fl ow-rate, An excessive fl ow in the secondary circuit could result in a temperature mixing
eff ect in the heater storage vessel, resulting in a stored water temperature less than set temperature.
See table below:-
It is important that the heat losses from the return system are minimised (through pipe
insulation), otherwise the heater may be operating for extended periods of time on minimum
load, constantly replacing the heat lost from the return system pipes.
Installation
Model Type
Maximum fl ow rate m 3 /h
MAXXfl o MAXXfl o
EVO 90 EVO 120
1.8 2.4
24 MAXXfl o EVO