Honeywell L8104B ユーザーズマニュアル

13

68-0063—3

L8104A,B,C,D

TROUBLESHOOTING

CHECK TRANSFORMER, 120V SUPPLY, 
CORRECT AS NECESSARY. 

IGNITION MODULE WAS IN LOCKOUT.
OBSERVE FOR 2-3 CYCLES TO MAKE 
SURE SYSTEM IS OTHERWISE OK.

SENSOR(S) MAY BE SHORTED OR 
OPEN. CHECK FOR LOOSE, BROKEN 
OR SHORTED WIRES.  REPLACE 
SENSING BULB(S) IF NECESSARY.

REPLACE ELECTRONIC CONTROL 
MODULE. RECONNECT ALL LEADS 
AND CHECK OUT SYSTEM. 

REPLACE POTENTIOMETER. 
RECONNECT ALL LEADS AND CHECK 
OUT SYSTEM.

NO

YES

NO

YES

CHECK VOLTAGE AT 24V TERMINALS 
OF ELECTRONIC CONTROL MODULE.

IS THIS AN ELECTRONIC IGNITION 
SYSTEM WITH 100 PERCENT LOCKOUT?

DISCONNECT 24V POWER AT IGNITION 
MODULE AND RECONNECT AFTER 
ABOUT 1 MIN. SET POTENTIOMETER TO 
MAX TEMPERATURE SETTING.

DISCONNECT ECO LEADS AND MEASURE 
RESISTANCE WITH OHMMETER.

DISCONNECT SENSOR LEADS FROM 
ELECTRONIC CONTROL MODULE AND 
MEASURE RESISTANCE OF SENSOR(S) 
WITH OHMMETER.

SENSORS OK. IS THE POTENTIOMETER 
REMOTE?

DISCONNECT POTENTIOMETER LEADS FROM 
ELECTRONIC CONTROL MODULE. MEASURE 
RESISTANCE OF POTENTIOMETER WITH 
OHMMETER.

POTENTIOMETER OK. REPLACE ELECTRONIC 
CONTROL MODULE. RECONNECT ALL LEADS 
AND CHECK OUT SYSTEM.

YES

NO

NO

YES

NO

YES

YES

YES

NO

NO

M135B

IS VOLTAGE BETWEEN 21.5 AND 
28.5 VAC?

DOES HEATER TURN ON?

IS RESISTANCE GREATER THAN 
100K OHMS (OPEN)?

IS RESISTANCE BETWEEN 700 AND 
30K OHMS (SEE TABLE 1)?

IS RESISTANCE GREATER THAN 1000 OHMS AT
MINIMUM TEMPERATURE SETTING AND LESS 
THAN 50 OHMS AT MAXIMUM TEMPERATURE 
SETTING (CHECKS FOR OPEN OR SHORTS)?

START

REPLACE SENSING BULB WITH ECO 
SWITCH AND OBSERVE SYSTEM IN 
OPERATION. IF WATER HEATER DOES 
NOT TURN OFF AFTER WATER 
REACHES SET POINT TEMPERATURE, 
REFER TO TROUBLESHOOTING IF 
WATER IS TOO HOT.

If water temperature is too cold or heater does not come on, proceed as follows: