Owner`s manual

Hydro-Hot Hydronic Heating System Shop Manual 07/03
R
Page 65
Section 8: Diesel-Burner Service, Maintenance, and Repair Information
Control Unit
8.11 Control Unit
Function: The Control Unit operates all the components of the Diesel-
Burner Head and safely shuts the heater OFF in the event of an overheat,
flameout,
and low voltage condition. It also receives Diesel-Burner
operation s
tatus signals from the Flame Sensor, VDC Control Thermostat,
and VDC High-Limit Thermostat.
Component Test: The following conditions must exist prior to performing
the Control Unit circuit tests on the following page. If one of the conditions
below does not exist, please contact our Technical Support Department at
1-800-685-4298 for additional assistance.
Condition #1
A battery voltage level of between 11.5 to 14.0 volts DC must be
present at the Control Unit during all testing, reference Figure 25. It
may be necessary to perform a voltage check to ensure that this
condition exists. To perform the voltage check, locate the Control
Unit's B-Plug, and insert the probes of a DC voltmeter into the B-4
(+) and B-2 (-) locations, reference Figure 26.
Condition #2
A voltage level of between 11.5 to 14.0 volts must be present at the
Diesel ON/OFF switch circuit of the Control Unit 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 Control
Unit's B-Plug, and insert the probes of a DC voltmeter into the B-1
(+) and B-2 (-) locations, reference Figure 8. Turn the Diesel switch
ON and observe the voltage level, reference Figure 4.
Diesel-Burner
Control Unit
Diesel-Burner
Head
Figure 25