On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
This guide assists Clinical Engineering in troubleshooting a 3M Bair Paws 875 patient warming unit when the blower appears to run but airflow is weak, inconsistent, or obstructed. Poor airflow prevents proper warming and may cause the system to shut down or alarm.
The guide focuses on checking simple and external causes first, such as hose connection issues, intake blockages, filters, and airflow restrictions before assuming internal blower failure.
Step-by-Step Troubleshooting
1. Confirm the Unit Powers On and the Blower Starts
- Turn the unit on and start a warming cycle.
- Observe:
- Does the blower start immediately?
- Do you hear normal fan noise?
- Is there any airflow at the hose outlet?
Why this matters: If the blower does not start at all, the problem may be electrical or internal rather than airflow restriction.
2. Inspect the Hose Connection
- Verify the warming hose is fully inserted into the front hose port, locked into place, and not cracked or damaged.
- Remove and reconnect the hose to ensure a proper seal.
Why this matters: Loose or damaged hose connections reduce airflow and may appear as weak blower performance.
3. Check the Disposable Blanket Connection
- Ensure the blanket hose port is not collapsed.
- Verify the blanket air channels are not folded or compressed.
- Confirm the blanket is compatible with the Bair Paws system.
Why this matters: Improperly connected or obstructed blankets restrict airflow and prevent heat from distributing properly.
4. Inspect the Air Intake Area
- Locate the rear or side intake vents on the warming unit.
- Check for dust buildup, drapes or linens blocking the vents, equipment carts or walls obstructing airflow, and tape or labels covering vent openings.
- Clear any obstruction and ensure at least several inches of clearance around the unit.
Why this matters: Restricted intake airflow will reduce blower output and can cause overheating protection to activate.
5. Inspect the Air Filter (If Accessible)
- If the intake filter is externally accessible, check for heavy dust accumulation and clean or replace the filter if necessary.
Why this matters: Clogged filters significantly reduce airflow and force the blower to work harder.
6. Run the Unit Without a Blanket Attached
- Disconnect the blanket and run the blower briefly.
- Observe airflow strength directly from the hose and any unusual sounds from the blower.
- If airflow improves significantly with no blanket attached, the restriction is likely in the blanket or hose.
Why this matters: This step isolates the blower from external airflow restrictions.
7. Listen for Abnormal Blower Operation
- While the unit is running, listen for grinding sounds, high-pitched whining, intermittent fan speed changes, or rattling noises.
Why this matters: These sounds may indicate internal blower wear, debris inside the blower housing, or fan motor degradation.
8. Check for Overheating Shutdown Behavior
- Observe whether the unit runs briefly then shuts off, displays overheating alarms, or reduces airflow over time.
Why this matters: Restricted airflow can cause internal overheating protection to activate.
If the Problem Persists
If hose connections, blankets, filters, and intake airflow have been verified and airflow is still weak, the issue is likely due to an internal blower motor problem or internal airflow restriction.
At this point:
- Remove the device from service
- Label the unit Out of Service
- Send the device for repair or bench evaluation
Internal blower components and heating systems should not be disassembled in the clinical environment. Knowing when to stop and escalate is proper troubleshooting.
Clinical Use Tip
Do not troubleshoot a patient warming system while it is connected to an active patient.
- Move the patient to another warming device first
- Then remove the suspected unit from service for evaluation
Patient temperature management should never rely on a device with suspected airflow problems.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
“Staff reported the Bair Paws warming unit was running but producing very weak airflow and the patient blanket was not warming properly.”
Cause
What was observed during troubleshooting.
Example:
“Air intake vents were partially obstructed by linens placed against the rear of the unit, restricting blower airflow.”
Resolution
What action was taken.
Example:
“Cleared vent obstruction, verified strong airflow from the hose outlet, and returned the unit to service after operational testing.”
Helpful Details to Include (If Known)
- Outlet tested and verified
- Hose connection inspected
- Intake vents inspected and cleared
- Filter condition checked
- Blower sound normal or abnormal
- Blankets and hoses inspected
- Final airflow verification completed
Final Thought
Weak airflow in patient warming systems is often caused by simple external restrictions such as blocked intake vents, dirty filters, or improperly connected blankets. Clinical Engineering troubleshooting should always start with these easily verifiable issues before assuming internal failure. Ensuring safe airflow protects both the equipment and the patient. Proper documentation and escalation when necessary are essential parts of effective equipment management.
That is successful troubleshooting.