Thermostat; Diagnostics - Detroit Radiant Products HLV Series Design, Installation, Operation, And Maintenance Manual

HLV Series

Thermostat

NOTE: Different thermostats operate according to their particular features. Refer to thermostat
specifications for details.
HLV Series heaters require a 24 V, two stage thermostat to operate. The burner control box is
equipped with a round terminal strip that accepts three (3) 1/4 in. insulated female spade terminals. Do
not supply 120 V to the 24 V connection.
Theoretical Example: The thermostat is set to 65°F. The thermostat's preset differential for
high fire mode is 3°F.
When the temperature drops below the set point of the thermostat (65°F), low fire will activate.
If the temperature continues to drop below the set point by another 3°F (62°F), high fire will
activate bringing the temperature back up to the thermostat's set point.

Diagnostics

The controls will automatically lockout the heater system when an external or system fault occurs.
Lockout: If proof of flame is not established, a component failure occurs or blockages are evident, the
heater will enter hard lockout. If lockout occurs, the control can be reset by briefly interrupting
the power source. Refer to Chart 4.1 below for a description of the control module diagnostic
indicator flash codes.
Chart 4.1 • Control Module Diagnostic Flash Codes
LED Flash Code
Steady ON
1 Flash
2 Flashes
3 Flashes
NOTE: Flash code indicator light is located internally on the control module.
Figure 4.1 • Operational Indicator Lights
Fault Status
Control Fault
Air Flow Fault
Flame - No call for heat
Ignition Lockout
Light 1* (amber)
*
Models with V-1SAO add-on are not equipped with high fire light.
4.0 Operation
Light 2 (amber)
Indicates High
Indicates Low
Fire Mode Fire Mode
Operational Indicator Lights
43
• Thermostat • Diagnostics
Light 3 (amber)
Pressure Switch