Page 17
Legacy
™
Model LRZM Pool/Spa Heater Installation and Operation Manual
5.2
Check Valve Installation
The heater must be protected from back-siphon-
ing of water, which can result in dry starts. If there is
any chance of back-siphoning, provide a check valve
between the pool and the
fi
lter pump inlet.
When an automatic chemical feeder is installed
in the plumbing, it must be installed downstream of
the heater (see Section 5.7). A check valve must be
installed between the heater and the chemical feeder to
prevent back-siphoning of chemically saturated water
into the heater where it will damage the components.
5.3
Automatic Flow Control Valve
The inlet/outlet header of the Legacy comes
equipped with an automatic
fl
ow control valve. The
automatic
fl
ow control valve maintains the proper
fl
ow through the heater at rates up to approximately
125 Gallons Per Minute (GPM) (475 liters per minute
[LPM]). If the
fi
lter system
fl
ow rate is higher than
approximately 125 GPM (475 LPM), install a manual
bypass valve (see Figure 7), then perform a tempera-
ture rise test (see Section 7.6) and adjust the
fl
ow using
the bypass valve until the proper temperature rise is
obtained.
5.4
Reversible Water Connections
NOTE
Reversing the header requires a longer
syphon tube, order part number R0483601.
The Legacy heater is shipped with water connec-
tions on the right side, but can be modi
fi
ed in the
fi
eld
to provide left-side water connections. This proce-
dure involves removing the heat exchanger headers
and reinstalling them on opposite ends of the tube
assembly. Some of the heater wiring must be discon-
nected and re-routed, so this procedure must be done
only by a trained service technician. Heat exchanger
reversals are generally done before the installation of
power and water to the heater. If you need to reverse
the heat exchanger on a previously installed heater be
sure that all electrical power, the gas supply and water
supply have been turned off before starting the proce-
dure. These instructions have been written to include
the steps needed when reversing the water connec-
tions on an existing installation. If you are reversing
the headers on a new installation, some steps will be
ignored. Water connection reversal is illustrated in
Figures 8 and 9. Proceed as follows:
1.
For an existing installation, drain the heater by
removing the two drain plugs on the inlet/outlet
header and the drain plug on the return header.
2.
Remove the heater front panel (door).
3.
Remove the I/O header side cover plates, top and
bottom. See Figure 10.
4.
Remove the return header side cover plates, top
and bottom. See Figure 10.
NOTE: When reversal
is complete the water
temperature sensor
wires and the syphon
loop tube will exit the
inlet/outlet header at
the back of the heater
and the drain plugs are
facing down.
Bypass
Assembly
Figure 8. Water Connections as Shipped
Figure 9. Water Connections Reversed
REAR PANEL
TOP PANEL
RIGHT SIDE PANEL
LEFT SIDE PANEL
RETURN HEADER SIDE
COVER PLATES
TOP AND BOTTOM
FRONT PANEL
(DOOR)
CONTROL PANEL
BASE
IN/OUT HEADER
SIDE COVER PLATES
TOP AND BOTTOM
VENT TOP
Figure 10. Legacy Panel Identi
fi
cation
Summary of Contents for Legacy LRZM
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