A.O. Smith 960 through 967 - Manual (Page 27)

ВТН S E R V I C E H A N D B O O K
T R O U B L E S H O O T I N G
BLOWER (CONTINUED)
BTH 250, 962 & 966 SERIES ONLY
(Models equipped with blower speed reduction board)
STEP 8B 120 VAC TO BLOWER FROM SPEED REDUCTION BOARD
BTH 250, 962 & 966 Series oniy
Blower Speed Reduction Board
Go to control
board CN 5
Go to control
board CN 6
Go to control
board CN 2
STEP 8B: CHECK FOR 120 VAC TO BLOWER FROM CN2 PLUG PIN 1 AND 2 ON BLOWER
SPEED REDUCTION BOARD.
Condition:
• Reconnect all plugs to control board.
• On/Off switch is on.
• Call for heat is activated.
Insert meter probes into back of CN2 plug on pins 1 and 2 with CN2 plugged into blower speed
reduction board. Power should be on with a call for heat activated.
IF... AND THEN
120 VAC is not present check CN2 plug connection, replace blower speed
reduction board if Step 8A has been performed and
results were successful.
120 VAC is present blower is not running check CN2 plug connection, replace the blower.
120 VAC is present blower is running continue to Step 8C.
STEP 8C: LISTEN FOR BLOWER TO REDUCE SPEED DURING IGNITOR WARM UP PERIOD.
IF... THEN
blower runs, but does not reduce speed or stops during ignitor warm up period replace blower speed reduction
board.
blower does reduce speed during ignitor warm up period continue to Step 9A.
Technical Training Department
TC-044 Revision 6
26
A. O. Smith Water Products Co.
Ashland City, Tennessee © 2004