Fault Code 44
BLOWER CALIBRATION
·HEATINGÐDuring a call for heat, the desired
When unit is operating in low heat and furnace control board (date code 9505 or earlier) is flashing Fault Code 44, it indicates that desired
When unit is operating in high heat and furnace control board (date code 9506 or later) is flashing Fault Code 44, it indicates that desired
·COOLINGÐIf desired cooling blower RPM is less than 250 or greater than 1300 RPM, furnace control board starts flashing Fault Code 44 and runs at default (or previous) cooling speed control signal for rest of cooling cycle. During this sequence, it is possible for furnace control board to start flashing Fault Code 41 instead of Fault Code 44. This indicates that blower calibration failed and blower speed for cooling is also out of range.
·CONTINUOUS FANÐIf desired continuous fan blower RPM is less than 250 or greater than 1300 RPM, furnace control board will start flashing Fault Code 44 and run at default (or previous) continuous fan speed control signal for the rest of continuous fan cycle. During this sequence, it is possible for furnace control board to start flashing Fault Code 41 instead of Fault Code 44. When this happens, it indicates blower calibration failed and blower speed for continuous fan is also out of range.
STEP | ACTION | YES | NO | GO TO | |
1. | Turn power off, wait 30 sec, then restore power. Reset thermostat. Observe operation of furnace |
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through 1 heating cycle. | Ð | Ð | 2 | ||
| NOTE: Blower access panel must be in place. |
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2. | Does Fault Code 44 flash twice followed by Fault Code 41? | 3 | 4 | Ð | |
3. | Eventually furnace will lock out on Fault Code 12 given enough time. Go to page number indicated | Ð | Ð | INDEX | |
in Index for Fault Code 12. | |||||
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4. | Does only Fault Code 44 occur? | 8 | 5 | Ð | |
5. | Does a different fault occur? | 6 | 11 | Ð | |
6. | Go to page number indicated in Index for fault code flashed. | Ð | Ð | INDEX | |
7. | Go to page number indicated in Index for CLEANUP AND | Ð | Ð | INDEX | |
8. | Does unit operate in low fire while flashing Fault Code 44? | 9 | 3 | Ð | |
| You have excessive restriction in air delivery system. Check filter(s) and ductwork. If problem still |
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9. | persists, replace furnace control board. Make sure replacement board has a date code of 9506 or | Ð | Ð | 10 | |
later. This new furnace control board will allow unit to run in high fire when necessary. See descrip- | |||||
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| tion of operation at start of Fault Code 44. If problem still persists, use Appendix E to evaluate. |
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10. | Fix problem. | Ð | Ð | 7 | |
11. | Turn power off, wait 30 sec, then restore power. Reset thermostat. Observe operation of furnace |
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through 1 cooling cycle. | Ð | Ð | 12 | ||
| NOTE: Blower access panel must be in place. |
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12. | Does Fault Code 44 occur? | 13 | 14 | Ð | |
13. | You have excessive restriction in air delivery system. Check filter(s) and ductwork. Furnace blower |
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will operate in cooling mode at default speed. Check outdoor unit suction pressure and verify | Ð | Ð | 10 | ||
| charge to determine if indoor airflow is sufficient. If not, refer to Appendix E to evaluate. |
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14. | Turn power off, wait 30 sec, then restore power. Reset thermostat. Observe operation of furnace |
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after it goes into high fire. | Ð | Ð | 15 | ||
| NOTE: Blower access panel must be in place. |
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15. | Does unit operate in high fire while flashing Fault Code 44? | 16 | 7 | Ð | |
16. | You have excessive restriction in air delivery system. Check filter(s) and ductwork. Furnace blower |
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will operate in | Ð | Ð | 10 | ||
| does not trip primary limit. If it does, refer to Appendix E to evaluate. |
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