Common Air Distribution Problems and Solutions
- Heating or central air conditioning does not work at all
- System runs but no hot or cold air flow
- Heating or cooling insufficient in part of the house
- Heating or cooling insufficient throughout entire house
- Air flow noisy
- Blower noise excessive
- Blower belt slips or squeals
Heating or central air conditioning does not work at all
| Possible Cause | Procedure |
|---|---|
| No power to unit | Reset circuit breaker or replace fuse |
System runs but no hot or cold air flow
| Possible Cause | Procedure |
|---|---|
| Blower belt broken or loose | Inspect and adjust belt tension |
| Fan-and limit control faulty | Test fan-and-limit control |
| Blower relay faulty | Test blower relay |
| Blower motor faulty | Inspect blower motor |
Heating or cooling insufficient in part of the house
| Possible Cause | Procedure |
|---|---|
| Register closed or blocked, or filter dirty | Open register and remove obstructions Replace filter |
| Blower blades dirty | Clean blower blades |
| Duct disconnected or damper closed | Reconnect duct or open damper |
Heating or cooling insufficient throughout entire house
| Possible Cause | Procedure |
|---|---|
| Air filter dirty | Replace filter |
| Blower running poorly | Oil blower motor and bearings |
| Blower bearings dry or worn | Lubricate bearings Call for service |
| Duct damper adjusted improperly | Adjust dampers |
Air flow noisy
| Possible Cause | Procedure |
|---|---|
| Blower speed too high | Adjust blower speed Call for service |
| Joints loose at duct corners | Tighten joints and adjust duct hangers Call for service |
Blower noise excessive
| Possible Cause | Procedure |
|---|---|
| Blower motor bearings dry or worn | Lubricate bearings Call for service |
| Motor or blower mounting hardware loose | Tighten mounting hardware |
Blower belt slips or squeals
| Possible Cause | Procedure |
|---|---|
| Belt tension incorrect | Adjust belt tension |
| Pulley misaligned | Align blower pulleys |
