HVAC System Failures: What to do Before Calling for Emergency Repairs
Quick Checks to Save Time, Money, and Disruption
When a commercial HVAC system fails, the impact on a business could be immediate. Whether it’s an office where staff can’t concentrate due to constant temperature changes, a retail space where customers feel uncomfortable, or a school facing compliance concerns, downtime will cost money.
It’s totally normal wanting to call for an emergency repair straight away, however not all system failures are true emergencies, and in lots of cases, the issue can be traced back to something quite simple. If you were to carry out a few quick checks before calling for help, you can sometimes get your system back online and avoid unnecessary callouts.
Common Causes of HVAC System Failures
Before diving into finding a solution, it could help to understand why HVAC systems fail in the first place. Some of the most common causes include:
Power interruptions or electrical faults that prevent systems from starting.
Dirty filters reducing airflow and causing overheating.
Mechanical wear and tear on fans, compressors, and pumps.
Poor maintenance practices that allow small issues to become bigger problems.
If you know some of these failure points, you will help your facilities managers and staff make more informed checks before jumping straight to emergency repairs.
What to Check Before Calling for Emergency Repairs
1. Verify Power Supply and Controls
Surprisingly, loss of power is quite a common cause of reported “failures.” To confirm that the unit is receiving power, check circuit breakers and fuses, and make sure that the Building Management System (BMS) controls are set correctly. A recent power cut could sometimes reset settings without any warning.
2. Inspect Air Filters
Dirty or clogged filters restrict airflow, forcing systems to work harder until they shut down altogether, so if the filters haven’t been changed recently, this could be the issue. For busy commercial environments, filters should be regularly replaced around every 1–3 months to avoid the build-up of any dust.
3. Look for Airflow Restrictions
Something along of the lines of blocked pipes or vents can all mimic HVAC failure by preventing conditioned air to create a healthier environment. You could walk the building and make sure airflow paths are clear of any blockages like boxes or furniture.
4. Listen and Look for Warning Signs
Before calling for help, take note of any unusual signs.
Noises: Grinding or banging may point to failing mechanical components.
Smells: Musty odours suggest mould growth, whereas burning smells may indicate electrical faults.
Leaks: Leaking could show signs of system stress.
This kind of information could be very useful to engineers and may reduce repair time and save the engineers patience!
5. Perform a Safe System Reset
If your system has a manufacturer-approved reset option, performing a controlled restart can sometimes resolve temporary issues. However, you should avoid resetting the system consistently and repeatedly because if the fault carries on, this can worsen the damage.
When It’s Time to Call for Emergency Support
If basic checks don’t resolve the issue, or if you notice more serious signs such as smoke, don’t wait any longer in calling an emergency engineer. If you continue using a faulty HVAC system, this can increase damage, raise safety risks, and extend downtime.
A few examples of when emergency repairs are especially critical is if indoor temperatures are unsafe, or if air quality is compromised, and is causing health risks.
Reducing the Risk of Future Failures
While these checks can help in the moment, the best way to avoid HVAC emergencies is through planned preventative maintenance (PPM). Regular servicing ensures filters are changed, components are inspected, and minor faults are fixed before they turn into breakdowns.
Other preventative measures include:
Seasonal servicing in spring and autumn.
Proactive replacement of ageing components.
System monitoring through BMS.
How William Austin Can Help
Here at William Austin, we have supported businesses, schools, and organisations across the UK with reliable commercial HVAC services for over four decades. Our team provides:
24/7 emergency repair support with fast response times.
Scheduled planned maintenance tailored to each site.
Diagnostics to find root causes and prevent repeat breakdowns.
Upgrade advice for energy-efficient and reliable replacements.
Be Prepared, Not Reactive
A sudden HVAC failure can feel overwhelming but taking a few simple steps before calling for emergency support can save your business money and save yourself from any unnecessary stress. By combining proactive maintenance with a trusted repair partner, facilities managers can protect their operations from the disruption of unplanned breakdowns.
Written by Will Judd
Published 04/09/2025