Teledyne EHE - Manual (Page 17)

Hi-E2 Page 15
To adjust the pressure switch, proceed as follows
(see Figure 23).
The pool filter must be clean before making this
adjustment. The heater does not have to be firing.
1. Turn the Flex Temp switch to OFF, and
make sure the pressure switch is at its lowest
setting. This is done by rotating the adjuster
counterclockwise as far as it will go.
2. Start the filter pump and confirm by means
of an ohmmeter that the pressure switch
closes (if the switch fails to close, replace it
with a switch which has a lower minimum
setting).
3. Turn Flex Temp switch to ON. Heater should
start.
4. Pry out the top rubber dirt plug.
5. Use a 7/32 inch Allen wrench to turn the
adjustment screw very slowly clockwise until
the heater goes off.
6. Slowly turn the pressure switch adjustment
screw counter-clockwise one-quarter turn.
The heater should come back on
7. Check the adjustment by turning the filter
pump OFF. The heater should shut off
immediately. If it does not, restart the filter
pump and repeat Steps 6 and 7. Check the
adjustment again.
8. Return the pool temperature control to the
desired temperature.
It may be necessary to repeat these steps to get a
proper setting. The switch must be set so that the
heater will not fire unless the pump is running. If a
proper setting cannot be reached, contact the factory
service department.
2L-6. Water Temperature Rise
The Hi-E 2 pool heater has an internal bypass
device which accommodates a wide range of water
flow. Its purpose is to assure that flow through the heat
exchanger is adequate to provide high efficiency
operation and prevent overheating even though flow
through the filter system may vary.
Correct water flow should be confirmed upon
start-up of the heater and in most servicing situations.
If flow is not normal, corrections must be made to the
pool system. If the system has an external flow bypass
(because of very high filter system flow), it should be
adjusted to provide proper flow through the heater.
Flow is evaluated by determining the water
temperature rise through the heat exchanger.
Before checking temperature rise, be sure the
pool filter is clean. If necessary, clean the filter.
Temperature rise is measured at the return header,
which is on the side opposite to the inlet/outlet header.
For access, remove the side cover, which is held in
place by wing nut fasteners inside the heater. Remove
the brass plug on the top surface of the header and
install a pocket thermometer (see Figure 24).
Proceed as follows:
1. If the piping system has a manual bypass
valve, close it.
2. Turn off the heater by moving the Flex Temp
switch on the temperature control panel to “Off”.
3. After three minutes, note and record the
thermometer reading. This is the pool temperature.
4. Start the heater and let it operate for at least
five minutes. Note and record the thermometer reading.
The difference between this reading and the first one is
the temperature rise.
5. If the piping system has a manual bypass
valve, gradually open it until the temperature rise is in
the range required by Table 6.
6. Scribe a line on the bypass valve shaft and
case to mark the correct adjustment position. Wire the
handle to the pipe to prevent tampering.
Note that temperature rise is somewhat less when
the water is hot (spa application) and when heater is
installed at elevations significantly above sea level. For
high elevation installations, reduce the numbers in
Table 6 by 3% per 1000 feet above sea level.
Minimum Maximum Minimum System
Model Temp Rise, Temp Rise, Flow
°F (C) °F (C) GPM
220 12 (6.5) 17 (9.5) 30
350 20 (11) 29 (16) 30
Table 6. Water Temperature Rise and Flow Rates
(Measured at Return Header)
In a system without external bypass, it may be
necessary to make changes. If temperature rise is too
low, a manual bypass must be installed. If temperature
rise is too high, there is inadequate flow, possibly
requiring a change to the piping system or a larger
pump. Before proceeding with either remedy, verify
proper heater operation. Low gas input results in low
temperature rise and vice-versa. A problem with the
heater internal bypass assembly also affects measured
temperature rise.
SECTION 3.
Operating Instructions
Lighting and shutdown instructions are posted
inside the heater.