Install Instructions

9
CAUTION
Any part of the paddle must not touch the pipe or any restrictions
in the pipe. Screw the ow switch in position so the at of the
paddle is at right angles to the ow. The arrow on the side case
must point in the direction of the ow.
The safety ow switch may be eld adjusted to obtain higher
minimum ow rates than those shown in Table 5.
To adjust the ow rate setting:
1. Remove the ow switch cover.
2. For higher ow rate—turn the range adjusting screw clockwise.
3. For lower flow rate—turn the range adjusting screw
counterclockwise.
CAUTION
The switch is factory set at approximately the minimum ow
rate, see Table 5. It must not be set lower than the factory
setting as this may result in the switch failing to return at a
“no ow” condition.
4. Replace the ow switch cover.
TABLE 5 - SAFETY FLOW SWITCH SETTINGS
Minimum Flow Rate (GPM/LPM)
Pkg. No.Contacts (ow) Closed Contacts (no ow) Open
Model GPM LPM GPM LPM
HW-120M, 160M 0.6 2.3 0.3 1.1 9005680205
HW-200M 4.2 15.9 2.5 9.5 9005680205
HW-225M 5.8 22.0 3.7 14.0 9005680205
The installer is cautioned to follow the manufacturer’s instructions
exactly when inserting this switch into a pipe tee. This is necessary
in order to assure positive action of the switch with water ow.
Once the minimum ow rate (Table 5) through the heater is
reached, the safety ow switch contacts close and consequently,
main burner operation is achieved.
DRAIN VALVE (NOT SUPPLIED)
A drain valve must be obtained and installed on each heater and tank
for draining purposes, see installation diagrams in this manual.
THERMOMETERS (NOT SUPPLIED)
Thermometers should be obtained and eld installed as shown in
the installation diagrams.
Thermometers are installed in the system as a means of detecting
a possible liming condition in the heater. An increase of 5
0
F over
the normal temperature rise through the heater is an indication that
lime is present. The term “temperature rise” designates the difference
between the heater inlet and outlet water temperatures.
An increase of 5
0
F (3°C) above the recorded temperature rise
may signify a liming condition in the coils or heat exchanger.
Refer to PREVENTIVE MAINTENANCE section of this manual
for deliming instructions.
Record temperature rise at initial start-up for future reference.
CAUTION: The paddle must be trimmed at the dotted arc. It must not touch the pipe or any restrictions when installed.
FIGURE 5