Lochinvar 399 - Manual (Page 50)

Hydronic Heating Boilers and
Domestic Water Heaters
50
OPERATION Continued
Diagnostic Status Indication
The ignition module has an LED which indicates the status of the
safety circuits. A remote Ignition Module Status indicating
light(s) is wired from the ignition module Status LED and
mounted on the front control panel. The flashing operation of
these light(s)/LED indicates the diagnostic status of the ignition
control module. The status LED, mounted on the ignition
module, flashes a code sequence from the Ignition Module to
indicate the status of the ignition process. See TABLE–U, this
page for the flashing diagnostic status codes as signaled by the
ignition module.
Access to Internal Control Panel
The control panel is accessed by turning the mounting screw
located at the bottom center of the exterior control panel. Pull the
panel out at the bottom. The door will tilt into unit until it comes
free from the outer top. The outer control panel has an overlay
attached to the exterior surface which indicates the function of
each of the boiler’s indicating lights and a clear window to view
the digital temperature display from the electronic temperature
control. The thermostat and diagnostic light board are mounted to
the back of the control panel door.
The control panel assembly is mounted on a slide out chassis to
allow easy access to the components on the panel. The control
panel contains the ignition module, transformer for the 24 VAC
control circuit, circuit breaker for the control circuit, switching
relays for component operation and wiring harness connections
to the unit’s components. The control panels are common and
may be switched between units for troubleshooting.
Removing the Control Panel
1. Pull the control panel out as far as it will go.
2. Remove the multi-pin connector blocks from the top and
right side of the control panel.
3. Use a 1/2" box wrench or socket wrench to remove the bolt
on the right side of the control panel.
4. Remove the entire control panel.
5. Reinstall the control panel in the reverse order.
Code Sequence Condition
Constant ON System OK, no faults present.
Constant OFF Possible control fault, check power; LED may be effective,
do not replace control if all operational sequences function
properly, see TroubleShooting Guide.
One Flash Low Air, check air pressure switch and hoses to pressure
sensing points, fan, venting and sealing of pressurized
chamber. Note: Brief flashing normal on fan start-
up/proving.
Two Flashes Flame without call for heat, check for a gas valve stuck in
the open position, air, venting, burners and the combustion
process. Fan will remain on.
Three Flashes Lockout due to flame failure, push reset button on inner
control panel after correcting ignition problem. Initial heater
start up without properly bleeding air from the gas line may
require multiple reset functions to achieve proper ignition.
Four Flashes Igniter failure, igniter will not maintain minimum 2.75 amp
current draw, caused by low voltage, bad wiring/continuity,
high resistance or igniter failure.
Five Flashes Power supply problem, check for low supply voltage or
transformer output less than 18VAC.
Six Flashes Replace ignition module, internal fault.
TABLE-U
Ignition Control Diagnostic Codes