Lochinvar 399 - 800 service manual Rem Ctrl Flt, Parameters, Progr, Open

FAULT

DESCRIPTION

CORRECTIVE ACTION

Outlet water temperature has exceeded the

• Verify that the boiler pump is set to the proper speed

Temp O/Shoot

maximum outlet water temperature.

or that the boiler pump is the proper size. Reference

Section 6 - Hydronic Piping of the Knight

XL

(continued)

Installation and Operation Manual for boiler pump

specifications.

• Replace the main control board.

External control is cycling too often.

• Check set point of the external control.

Rem Ctrl Flt

• Check the wiring between the external control and the

unit.

• Replace the control.

Parameters

After downloading parameters from a laptop,

• Press the ENTER/RESET button on the SMART

the main control board must be reset.

SYSTEM display panel.

Progr

(will require a manual

reset once the condition

has been corrected. Press

the RESET button on the

SMART SYSTEM display

to reset.)

APS

Air pressure switch contacts are open.

• Check the wiring connections to switch. Wires should

be connected to the common and normally closed

Open

terminals.

(will require a manual

reset once the condition

• Vent/air intake lengths exceed the maximum allowed

has been corrected. Press

lengths. Refer to Section 3 - General Venting of the

the RESET button on the

Knight XL Installation and Operation Manual

for

SMART SYSTEM display

proper lengths.

to reset.)

• Check for obstruction or blockage in the vent/air

intake pipes or at terminations.

• Check reference hoses connected to the air pressure

switch for blockage or obstruction.

• Inspect the burner. Reference page 26 of this manual

for removal and cleaning procedures. Replace if

necessary.

• Inspect the heat exchanger. Reference page 27 of this

manual for removal and cleaning procedures.

Replace if necessary.

• Faulty air pressure switch. Replace switch.