A.O. Smith 120 trough 500, Service Handbook, Page: 31 / 55

BTR TANK TYPE HEATERS
SERVICE HANDBOOK
A.O. Smith Water Products Service Handbook
Irving, Texas ©2000 Training Department
30
TROUBLESHOOTING THE EFFIKAL STYLE DAMPER
Condition:
Thermostat closed, damper
STEP A1
TEST BETWEEN BLACK (COMMON) AND BROWN
ON THE DAMPER BOARD
IF THEN
24VAC is present This is correct
24VAC is not present
•
See Steps 1 thru 4
Check the harness plugs connecting heater
and damper for looseness or damage.
Condition:
Thermostat closed, damper in process of opening.
STEP A2 TEST FOR 24VAC BETWEEN BLACK AND ORANGE
IF THEN
24VAC is present This is correct
24VAC is not present
•
See Step 7
•
Check the harness plug connecting
heater ----or damaged
Wires are from left to right:
Black
i
Yellow
i
Brown
i
White