Short answer: the five mistakes behind most UPS failures are skipping or stretching out preventive maintenance, ignoring battery age and test readings, letting the room run hot or dusty, clearing alarms without finding the cause, and working inside the unit without training or a procedure. Each one is avoided with a maintenance schedule, recorded measurements and a qualified technician.
In Canada? GDF Technologies provides 24/7 UPS service across Canada, with rapid emergency dispatch: 1 to 3 h on site in the Montreal area, same day in Quebec City, Toronto and Ottawa, and 24 to 48 h elsewhere. Call 514-252-8324 or request service; we reply within 4 business hours. See our UPS preventive maintenance service.
Updated 13 October 2026 by GDF Technologies, Montreal.
UPS maintenance is central to keeping critical infrastructure running, whether it protects a data centre, a hospital or a plant where every minute of downtime counts. Since 2012, our technicians have seen the same failure patterns again and again: small oversights that, left alone, turn into downtime, repair bills and sometimes lost data or production. This article covers the five mistakes we meet most often on UPS maintenance, and how to avoid each one.
1. Skipping planned preventive maintenance
The first mistake, and often the most expensive, is having no preventive maintenance plan, or one that is followed only when someone remembers. In our experience, most UPS failures could have been anticipated by a regular routine of checks.
- A neglected UPS can look healthy on its display and still be unable to carry the load when the power actually goes out.
- As a minimum, plan two preventive maintenance visits a year under a professional preventive maintenance agreement: electronics checks, firmware updates, inspection of the room, cleaning and functional transfer tests.
- Keep a detailed log of each visit and the readings taken. Trends in those readings are what reveal a slow drift before it becomes a failure.
2. Underestimating battery testing and replacement
The battery is the heart of the UPS, and its weakest point. In 150 GDF Technologies service reports, batteries at or past the end of their life were the most common finding: 35% of reports. See also our guide to UPS battery management.
- Depending on the type (sealed lead-acid VRLA, lithium-ion and others), battery life ranges from 3 to 10 years. It drops sharply when the room runs above 25 °C or when the batteries see frequent charge and discharge cycles.
- Without regular tests (voltage, internal resistance, and a visual check for swelling or leaks), runtime falls without anyone noticing, and the batteries fail during the next outage.
- Always replace batteries as a complete set of the same age and make. Mixing a new block with old ones unbalances the string and shortens the life of the new block.
- Have a capacity test and planned battery replacement done by trained technicians, who will also recalibrate the runtime estimate after installation (a step that is very often skipped).
3. Ignoring ventilation and room temperature
Another common trap: a UPS installed in a cramped space, without proper ventilation or next to a heat source (a closed rack, an electrical cabinet, a damp basement). Heat is the main enemy of both batteries and electronics.
- Under the industry rule cited in our technical documents, each 8 °C above 25 °C roughly halves the life of a VRLA battery.
- Clean vents and air filters at least every 6 months, so dust does not build up on the fans and overheat the internal components.
- Check regularly that the space around the UPS is clear and that the room stays at a stable temperature, ideally between 20 °C and 25 °C.
4. Clearing alarms without finding the cause
Modern UPS units (APC, Eaton, Tripp Lite, Delta and others) run detailed diagnostics and raise specific codes and alarms. Too often these alerts are silenced or reset without anyone looking into them. An alarm is a warning to act on, not a nuisance.
- Every error code (overload, short circuit, thermal fault, low battery) should lead to a real check of the installation or a technician’s visit, not just a manual restart.
- Read the technical manual to understand and correct the cause before restarting the system. Otherwise the same fault can take the load down at the worst moment.
- Book a visit from a qualified UPS specialist as soon as the same alarm comes back more than once.
For brand-specific guidance, see our pages on APC UPS maintenance and Eaton UPS maintenance.
5. Working inside the UPS without qualified staff
We still see high-risk work done without precautions: units opened while energized, wiring changed on the fly, non-original parts or the wrong batteries fitted. These practices raise the risk of electrical injury and fire, and can void the manufacturer’s warranty.
- Only trained, qualified staff should work on a UPS or a battery cabinet (our team is available 24/7 for this kind of critical work).
- Parts or batteries of doubtful origin raise the risk of an immediate or delayed failure, and of an electrical fire (UL, CSA and NFPA requirements).
- Document everything: each change or intervention should be recorded so the system stays traceable and compliant.
If the UPS has already failed, see our UPS repair service.
The takeaway: UPS reliability starts with method and anticipation
Continuous power is never an accident. Modern equipment, whether APC, Eaton, Tripp Lite or Delta UPS systems and their replacement batteries, only delivers full protection when its preventive maintenance is done regularly and professionally. A neglected unit quickly becomes a weak point, for cybersecurity as much as for electrical protection.
Want a review of your UPS fleet, a full diagnostic or a compliance audit of your critical infrastructure? Contact GDF Technologies for a plan built around your site: our team answers emergencies and project requests 24/7.
Frequently asked questions
What is the most expensive UPS maintenance mistake?
Having no planned preventive maintenance. Without regular visits, a worn battery or a failing fan goes unnoticed until the outage that drops the load.
How often should a UPS be serviced?
At least twice a year for an office UPS, and every quarter for a server room, a hospital or an industrial site. The manufacturer’s manual and the age of the batteries can justify more frequent visits.
Can I ignore a UPS alarm that clears by itself?
No. An alarm that keeps coming back often points to a battery at the end of its life, overheating or a charger fault. Note the message and the time, check the event log, and have the unit diagnosed if the same alarm returns.
Who can service a UPS in Canada?
GDF Technologies, a UPS service company based in Montreal and in business since 2012, maintains APC, Eaton, Tripp Lite, Vertiv and Liebert, Mitsubishi, Toshiba, Delta and XPC UPS systems across Canada, with rapid emergency dispatch: 1 to 3 h on site in the Montreal area, same day in Quebec City, Toronto and Ottawa, and 24 to 48 h elsewhere. Call 514-252-8324.
