NOTICE: When the heater is mounted more than five feet
above or two feet below the deck level, a Pressure Switch
is no longer adequate. A Flow Switch must be installed
instead.
NOTICE: Heater operation with incorrect Pressure Switch
setting may cause operation with no water flow. Operation
of the heater without sufficient water flow may severely
damage it.
Verify proper operation of the water pressure switch at the
start of every season and every six months thereafter by the
following steps:
1. Lower the thermostat setting to turn off the heater.
2. Wait at least 15 minutes after the burner is off, and
then turn off the filter pump.
3. Turn up the thermostat as though to fire the burner.
4. Wait one minute. The “Service System” light should go
on but the burner should not fire and the blower should
not start. If the blower or burner do start, or if the
“Service System” light does not go on, there is a pres-
sure switch malfunction. Immediately press the OFF but-
ton on the operating control to turn the burner off and
call a qualified service technician to check the system.
Live steam hazard. If the Burner and the
Pump stop at the same time, wait at least 15 minutes
before starting the filter pump to avoid severe damage to
the heater.
PRESSURE RELIEF VALVE
A pressure relief valve is not supplied with the heater.
Some local codes may require installation of a pressure
relief valve. If your local code requires a relief valve, install
a 3/4” pressure relief valve complying with the ANSI/ASME
Boiler and Pressure Vessel Code, having a capacity equal
to the Btu/hr rating of the heater. The relief pressure of the
valve MUST NOT EXCEED 50 PSI.
A 3/4” NPT connection is provided in the manifold for
installing a pressure relief valve. The relief valve must be
installed vertically. To install the valve, use a 3/4” brass
nipple and elbow, as illustrated in Figure 20. No valve is
allowed to be placed between the manifold adapter and
the relief valve.
Relief Valve Installed
User
supplied
pipe
fittings
2681 1096
Pipe relief valve discharge
to a drain or other safe
disposal site.
FIGURE 20: Relief Valve (Check Local Codes)
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