Fluid Circulation Pump
©Aqua-Hot®
250-D03 Diesel Series Service Manual
REV 220302
p. 71
Condition 1:
A battery voltage level between 11.6-14 Volts DC must be
present at the diesel burner controller during all testing.
It may be necessary to perform a voltage check to ensure
that this condition exists. To perform the voltage check,
locate the controller’s B-plug and insert the probes of a
DC voltmeter into the B-4 (+) and B-2 (-) pins.
Condition 2:
A voltage level of between11.6-14 volts must be present
at the diesel ON/OFF switch circuit of the diesel burner
controller during all testing. It may be necessary to perform
a voltage check to ensure that this condition exists. To
perform the voltage check, locate the controller’s B-plug
and insert the probes of a DC voltmeter into the B-1
(+) and B-2 (-) locations. Turn the diesel burner ON and
observe the voltage levels.
Ground Circuit Test:
Locate the controller’s B-plug and C-plug. Insert the
probes of a DC voltmeter into the B-4 (+) and C-5 (-)
locations and turn the diesel burner ON. If a voltage
reading does not register on the voltmeter, the controller
must be replaced. If voltage is present, proceed to the
next test.
ETS Module Circuit Test:
Locate the diesel-burner controller’s B-plug and C-plug.
Insert the probes of a DC voltmeter into the C-1 (+)
and B-2 (-) locations and turn the diesel burner ON. If a
voltage reading does not register on the voltmeter, the
Burner Components
Diesel Burner Controller
The diesel burner controller operates all the components of the
diesel burner head and safely shuts the heater OFF in the event
of an overheat, flame-out, and low voltage condition. It also
receives diesel burner operation status signals from the flame
sensor, control thermostat, and DC high-limit thermostat.
Component Test:
The following conditions must exist prior to performing the
following diesel burner controller circuit tests. If one of the
conditions below does not exist, please contact Technical
Support at 1 (800) 685-4298 for assistance.
NOTE:
Before troubleshooting the Diesel Burner Controller,
verify that the Burner has voltage at Pin 4 as shown in Figure
115. There will only be voltage on that pin if the burner
status is shown as ON.
Aqua-Hot Controller
Figure 114
Figure 115
Controller B-Plug & C-Plug
Figure 113
