Lochinvar 402 - 2072 Fault, Cause, Corrective Action, Troubleshooting, No Display, No Burner

Copper-fin II/IIE Boiler, Water Heater and Pool Service Manual

3 Troubleshooting

Table 3A Troubleshooting Chart - No Display

FAULT

CAUSE

CORRECTIVE ACTION

•

Check external line switch, fuse, or breaker.

• Check position of ON/OFF switch. Turn switch to the

- No 120 VAC supplied to unit.

ON position.

• Check 120 VAC

through

the

ON/OFF switch.

No

voltage through switch, replace switch.

No Display

• Check wiring harness connection between the display

- Bad wiring connection.

board and the main control board. Connect the harness

at both points.

- Blown fuse.

•

Replace

fuse

F6

on

the

main

control board,

see

FIG. 3-1 on page 31 of this manual.

- Bad display board.

•

Replace board.

- Bad main control board.

•

Replace main control board.

- Main control board temperature set point

•

Review temperature setting.

satisfied.

- Remote thermostat satisfied.

•

Review remote thermostat setting.

No Burner

- Outside air temperature above Warm

•

Check

location

of

outside

air

sensor.

Check

Operation

Weather Shutdown (WWSD) set point for

resistance of outdoor air sensor and compare to Table

main control board.

3D on page 33 of this manual.

- Unit locked out on fault.

•

Consult

display for

specific

fault.

Refer

to

fault

descriptions on pages 35 - 42 of this manual for

corrective actions.

- Ramp delay active.

• Check ramp delay parameter settings. Optional PC

software required.

Unit Does Not

•

Turn ramp delay

feature

off.

See

page 18

of

this

manual for instructions on how to turn this feature off.

Modulate to

100%

- Boiler controlled by BMS.

• Check

BMS

parameter

settings.

Optional

PC

- Outlet temperature too high.

software required.

- Delta T too high.

32