What Happens When an Appliance Fails PAT Testing?

When an Appliance Fails PAT Testing

Having an appliance fail a PAT test is not a disaster — it is the system working as intended. The purpose of PAT testing is to identify faults before they cause harm. Here is what happens when an appliance fails, and what your options are.

What Counts as a Fail?

An appliance can fail on visual inspection (before any electrical testing) or during the electrical tests themselves. Common reasons for failure include:

• Visual failures: Damaged cable, cracked plug, missing earth pin sleeve, cable not properly secured in the plug, damaged casing, signs of overheating or burning
• Earth continuity failure: The earth connection is too high resistance or absent — common in older equipment or items with damaged cables
• Insulation resistance failure: The insulation between live parts and accessible parts has broken down — a potential shock hazard
• Earth leakage failure: Current is leaking to earth beyond acceptable levels

Immediate Steps

When an appliance fails:

1. The appliance is immediately labelled as FAILED with a red sticker
2. It is removed from use — it must not be used until the fault is rectified
3. The failure is recorded on your PAT testing register with details of the fault
4. You are informed of the failure and the reason

Your Options

Repair: Some failures can be repaired — a damaged plug can be replaced, a loose cable can be re-terminated, or a frayed section of cable can be cut back. After repair, the appliance must be re-tested to confirm it now passes.

Replace: If the appliance is old, cheap, or the fault is internal (insulation breakdown), replacement is usually more cost-effective and safer than repair.

Dispose: Failed appliances that are not worth repairing should be disposed of properly. Do not leave them in a cupboard where someone might plug them in later — cut the cable off or clearly mark them for disposal.

Re-Testing After Repair

Any appliance that fails and is subsequently repaired must be re-tested before being returned to service. This confirms the repair has resolved the fault and the appliance is now safe.

Failure Rates

In our experience across businesses in Greater Manchester and Northwest England, typical failure rates range from 2-5% for well-maintained office equipment to 10-15% for construction tools and older catering equipment. If your failure rate is significantly higher than this, it may indicate that your equipment needs replacing or that your testing interval needs shortening.

Questions About Failed Appliances?

Contact Green Tag PAT if you have questions about failed appliances or need re-testing after repairs.