4
used. If equipped with manual feed,
close the system water supply
valve when a pressure reading of
12 psi is obtained. The purge valve
may have to be bled to reduce
pressure to 12 psi.
Check the system for leaks by shutting
the water supply valve and observing
the pressure gauge. Any decrease in
system pressure indicates a leak that
must be repaired prior to operation.
5. Set the thermostat at the lowest
setting. Turn the supply breaker for
the TDE at the main circuit breaker
panel to on. Turn all TDE breakers
to on.
6. Raise the thermostat to above room
temperature. The unit should oper-
ate. The pump and heater element
relays will cycle on and off accord-
ing to demand of the thermostat
and timing sequence. See the
Sequence of Operation section in
this manual for time delay descrip-
tion.
7. The pressure of the system will rise
when heated. The normal pressure
gauge reading should be between
20 and 22 psi. If pressure rises
above 22 psi, additional expansion
tank capacity may be necessary.
See the manufacturer’s manual for
information on sizing the expansion
tank.
Note:
The pressure relief valve is a safety
device set to open at 30 psi.
8. Set the heat anticipator in the ther-
mostat in accordance with the man-
ufacturers directions, if so
equipped.
When installation is complete and
the system is operating satisfac-
torily, close the cabinet door and
re-install the door holding screw
to prevent accidental or uninten-
tional opening of the door.
SEQUENCE OF OPERATION
The thermostat closes on a call for heat
and energizes the circulator relay and
the first heater relay which pulls in the
circulator and two heating elements.
The remaining elements are energized
on at one minute intervals (two ele-
ments at one time). When the thermo-
stat is satisfied, all the elements de-
energize at once and the circulator
stops.
Operating temperatures on the
temperature gauge of the TDE
may be 110 - 140° F, or lower.
This is normal for the TDE.
This unit is furnished with a dual hot
water control aquastat with a High Limit
Safety Setting (labeled “Hi”) and an
Operating Control Limit Setting (labeled
“Lo”). The High Limit Safety is factory
set at 200°F. The Operating Control
Limit is set at 170°. If the boiler water
reaches 170° the Operating Control
Limit will open the heater relay circuit
causing heater elements to de-energize,
even though the thermostat may be
calling for heat. The circulator will con-
tinue to run, as long as the thermostat
is calling for heat. When boiler water
temperature drops to 160° the
Operating Control Limit will close and
bring the heating elements back on,
provided that the thermostat is calling
for heat.
