Power Surges & Equipment Damage – Insurance Implications

Introduction

A power surge is a sudden spike in voltage that can damage electrical and electronic equipment. For UK businesses, the impact is rarely limited to a single burnt-out device. A surge can take out routers, servers, CCTV, EPOS systems, refrigeration, manufacturing controls, and even safety systems—then trigger downtime, missed orders, and reputational headaches.

From an insurance perspective, power-surge losses sit at the crossroads of property damage, equipment breakdown, and business interruption. Whether a claim is paid (and how much) often comes down to the cause of the surge, the type of policy you hold, and how well you can evidence the loss.

This guide explains the common causes of power surges, the typical insurance routes for cover, the exclusions that catch businesses out, and the risk controls that can reduce both incidents and disputes.

What causes power surges (and why insurers care)

Insurers focus on cause because different causes can fall under different insured perils—or be excluded.

Common surge causes include:

• Lightning and storms: A nearby strike can induce a surge through overhead lines, external cabling, or building wiring.
• Grid switching events: Voltage spikes can occur when the network is reconfigured, after faults, or during restoration.
• Internal electrical faults: Loose neutrals, failing breakers, worn wiring, or incorrect earthing can create damaging transients.
• High-load equipment cycling: Motors, compressors, welders, lifts, and HVAC can generate spikes when switching on/off.
• Generator/UPS issues: Incorrect changeover, poor maintenance, or misconfigured UPS systems can cause instability.
• Construction works: Damage to cables, temporary power setups, or poor site electrics can affect neighbouring premises.

Why it matters: a surge caused by lightning may be treated as a storm-related event under property cover, while a surge caused by wear and tear or poor maintenance may be excluded unless you have the right extensions.

What gets damaged (and what it really costs)

Surges don’t only “blow” equipment. They can degrade components and shorten lifespan, leading to repeat failures.

Typical affected items:

• IT and comms: servers, NAS, switches, routers, Wi‑Fi access points, VoIP systems
• Payment and retail systems: EPOS terminals, card readers, tills, barcode scanners
• Security and compliance: CCTV, access control, alarm panels, fire detection interfaces
• Cold storage and catering: fridges/freezers, controllers, combi ovens, extraction systems
• Manufacturing and engineering: PLCs, VFDs, CNC controls, sensors, test rigs
• Medical and lab equipment: diagnostic devices, sterilisation units, calibration equipment

The “hidden” costs often drive the claim value:

• Data corruption and recovery
• Emergency call-out fees
• Temporary hire of replacement equipment
• Spoilage (e.g., food, pharmaceuticals)
• Lost revenue and extra costs to keep trading

Where power-surge cover sits in business insurance

There isn’t one universal “power surge policy”. Cover is usually found in one or more of these sections.

1) Commercial property (buildings and contents)

Many commercial property policies cover contents against defined perils such as fire, flood, storm, and sometimes “accidental damage”.

Power-surge damage may be covered when:

• The surge is linked to an insured peril (for example, lightning or storm)
• The policy includes accidental damage to contents
• The wording includes electrical surge or damage by electricity as an insured cause

Common friction points:

• Some policies treat “damage by electricity” as excluded unless fire occurs.
• Some include a low inner limit for “electrical surge” losses.
• Some require evidence of an external event (e.g., storm reports, network incident notes).

2) Equipment breakdown (engineering) insurance

Equipment breakdown (often called engineering breakdown) is designed for sudden and unforeseen mechanical or electrical failure—especially for plant, machinery, and critical equipment.

This can be a strong route for surge-related losses where:

• The failure is internal to the equipment (e.g., power supply, control board)
• The property wording is restrictive on “damage by electricity”
• You need cover for expediting expenses (overtime, express shipping) to get running again

Engineering policies may also offer:

• Business interruption triggered by equipment breakdown
• Cover for deterioration of stock (spoilage) due to breakdown

3) Business interruption (BI)

BI doesn’t cover the damaged equipment itself; it covers the financial impact of downtime—typically loss of gross profit and sometimes increased cost of working.

BI may respond if:

• There is insured damage under the property or engineering section
• The interruption is within the policy’s indemnity period
• The loss is properly evidenced (turnover trends, accounts, order logs)

Watch-outs:

• BI often requires material damage first (a “damage proviso”).
• If the only issue is a power cut from the grid with no damage at your premises, you may need a public utilities or denial of access

4) Cyber insurance (sometimes)

Cyber policies generally focus on malicious events (hacking, ransomware), but some include cover for:

• Data restoration
• System failure (non-malicious outages) as an optional extension

A pure power surge is usually not “cyber”, but if the main loss is data recovery and the policy includes system failure, it may be relevant. This is highly wording-dependent.

Common exclusions and limitations (the bits that cause claim disputes)

Every insurer’s wording differs, but these themes are common.

Wear and tear, gradual deterioration, and maintenance

If the insurer argues the failure was due to ageing components, poor maintenance, or defective wiring, they may decline or reduce the claim. Engineering cover can still exclude wear and tear but may cover resultant damage.

Faulty workmanship or defective design

If a surge is linked to incorrect installation, poor earthing, or non-compliant electrical work, insurers may investigate whether:

• The work was carried out by a competent contractor
• Electrical certification exists
• The defect existed before inception

Electrical/electronic breakdown exclusions in property policies

Some property policies exclude “electrical breakdown” unless:

• Fire follows, or
• The policy includes an extension for electrical damage

Inner limits for surge, data, and portable electronics

Even when covered, you may face:

• Inner limits (e.g., a cap for “electrical surge” claims)
• Separate limits for computer equipment
• Lower limits for portable items

Excesses (deductibles)

Electrical damage claims can attract higher excesses, especially in storm-heavy areas or for certain trades.

Underinsurance and average

If your contents sum insured is too low, insurers may apply average, reducing the payout proportionally. This is common when businesses add expensive equipment over time but don’t update values.

What insurers typically need to assess a surge claim

Fast, organised evidence can reduce delays.

You’ll usually be asked for:

• Incident timeline: when it happened, what you noticed, what stopped working
• List of affected equipment: make/model/serial numbers, age, and replacement cost
• Engineer’s report: cause of failure, confirmation of surge damage, repair vs replace
• Photos: damaged components, error codes, burnt PSUs, tripped breakers (where safe)
• Maintenance records: PAT testing, service logs, electrical inspection reports
• Proof of ownership and value: invoices, asset register, lease/hire agreements
• BI evidence (if claiming): sales reports, accounts, job sheets, bookings, order cancellations

If the surge may be external, it can help to obtain:

• Weather reports for the time and postcode
• Any network incident confirmation from the electricity network operator (where available)

Practical examples: how cover can play out

These examples are illustrative; outcomes depend on wording and facts.

Example A: Lightning-induced surge damages server and router

• Likely route: property contents (storm/lightning) and possibly computer equipment section
• BI: may respond if the outage causes trading loss and damage is insured
• Key evidence: engineer confirms surge; weather/lightning activity supports cause

Example B: Internal wiring fault causes repeated controller failures

• Likely route: may be disputed under property; engineering may respond depending on exclusions
• Potential issue: insurer argues pre-existing defect or poor maintenance
• Key evidence: electrical inspection, remedial works, competent contractor documentation

Example C: Surge destroys refrigeration controller and stock spoils

• Likely route: engineering breakdown for equipment + deterioration of stock extension
• BI: could apply if the business cannot trade
• Key evidence: temperature logs, stock records, disposal evidence

How to reduce risk (and make claims easier)

Insurers like controls that reduce frequency and severity.

Electrical protection and resilience

• Install surge protection devices (SPDs) at the distribution board and at sensitive equipment
• Use UPS for servers, EPOS, and comms—configured and maintained properly
• Separate sensitive circuits from high-load machinery where possible
• Consider power conditioning for critical electronics

Maintenance and compliance

• Keep electrical inspection and testing up to date (and retain certificates)
• Log faults and repairs; don’t ignore “nuisance trips”
• Use competent contractors and keep documentation of works

Asset and data discipline

• Maintain an asset register with values and serial numbers
• Keep offsite backups and test restores
• Document your disaster recovery steps (who does what, in what order)

Insurance housekeeping

• Review sums insured annually (and after major equipment purchases)
• Check whether you have:

• accidental damage
• electrical surge extension
• engineering breakdown
• deterioration of stock
• BI with an adequate indemnity period

What to do immediately after a suspected surge

Your actions can affect both safety and claim outcomes.

1. Make it safe: isolate affected circuits if needed; don’t re-energise unsafe equipment.
2. Prevent further damage: unplug sensitive devices; use surge-protected temporary power.
3. Document everything: photos, notes, timestamps, what was running.
4. Call a competent engineer: obtain a written report on cause and remedy.
5. Notify your insurer/broker promptly: ask what evidence they need and whether you can authorise repairs.
6. Keep damaged parts: insurers may want inspection of boards/PSUs.
7. Track downtime and costs: labour, hire, overtime, lost sales, cancelled jobs.

FAQs

Are power surges covered by business insurance?

Sometimes. It depends on the cause of the surge and your policy wording. Some property policies cover surge damage only when linked to an insured peril (like lightning), while others require accidental damage or a specific electrical damage extension. Engineering breakdown cover can be a better fit for electrical failure of machinery and controls.

Will insurance cover a surge that damages computers but doesn’t cause a fire?

It can, but not always. Some policies exclude “damage by electricity” unless fire follows. Others include cover for electrical damage, computer equipment, or accidental damage. Always check for inner limits and higher excesses.

Does business interruption cover apply to power surge losses?

BI usually applies only if there is insured damage under the policy (property or engineering). If the grid goes down but you have no damage at your premises, you may need a public utilities extension.

What if the surge was caused by faulty wiring in my building?

Insurers may investigate maintenance and compliance. If the issue is linked to a pre-existing defect or poor workmanship, cover may be limited. Having up-to-date electrical inspection reports and evidence of competent work can help.

Can I claim for spoiled stock after a surge?

Possibly, if your policy includes deterioration of stock/spoilage cover and the spoilage results from insured damage or breakdown. Temperature logs and stock records are often important.

What evidence should I keep for a surge claim?

Keep an incident log, photos, engineer reports, invoices, asset register details, maintenance certificates, and records of downtime and extra costs. If relevant, keep weather information and any confirmation of network incidents.

Final thoughts + CTA

Power surges are common, but the insurance response is not always straightforward. The best outcomes come from matching the right cover (property, engineering, BI, and sometimes cyber extensions) to the way your business actually uses equipment—and from keeping strong maintenance and documentation.

If you’d like, I can help you review your current cover structure and identify where surge-related losses might fall through the cracks. For advice tailored to your business, speak with a specialist broker and request a clear explanation of surge, electrical damage, and equipment breakdown cover in writing.