Top 5 Ways to Winter-Proof Your Commercial HVAC System

Winter has a habit of sneaking up on us, one minute you’re enjoying a crisp autumn morning, the next you’re wondering why your building feels like the inside of a walk-in freezer. For commercial sites, facilities teams, and anyone responsible for making sure people don’t spend their workday shivering, winter-proofing your HVAC system isn’t just nice to have… it’s essential.

A well-prepared system runs more efficiently, costs less to operate, reduces downtime, and keeps your building’s occupants comfortable without needing to wear three layers and a scarf. At William Austin, we see the same winter pitfalls every year, and trust us, you don’t want to be the site that discovers an issue on the first frosty Monday morning of January.

So here’s your guide. Simple, practical, and sprinkled with some personality (because HVAC doesn’t have to be boring).

1. Check (and Protect!) Your System’s Frost Protection Settings

If there’s one thing that can cause expensive winter callouts, it’s a system left without proper frost protection. When temperatures drop, water in pipework can freeze, expand, and cause leaks, damage, or system failures, none of which look great on your maintenance budget.

Frost protection is designed to automatically kick in when temperatures fall close to freezing, ensuring circulation pumps operate and heating activates just enough to prevent ice build-up.

Why it matters for winter:

• Prevents burst pipes and cracked coils

• Reduces emergency repair costs

• Keeps vital areas (like plant rooms) safely above freezing

Pro tip: Don’t assume frost protection is set correctly “out of the box.” Make sure your BMS or standalone controllers have accurate temperature sensors and correct setpoints. A quick check now can save you thousands later — and your future self will thank you.

2. Replace Dirty Filters (Your System Will Breathe Again)

Air filters tend to get ignored… until airflow drops, heating struggles, or someone wonders out loud, “Why does it feel stuffy in here?” Winter is when your HVAC system works harder than ever, so dirty or clogged filters can seriously slow performance and increase energy usage.

Why it matters:

• Improves HVAC efficiency

• Reduces energy consumption (good for budgets and sustainability targets)

• Prevents strain on fans and heating components

William Austin engineers see blocked filters more often than we’d like to admit, thankfully, replacing them is quick, cost-effective, and one of the easiest wins to prepare for winter.

3. Inspect and Test Heating Components Before You Need Them

The first cold day of the year almost always reveals which buildings haven’t tested their heating early enough. Boilers, heat pumps, and warm-air systems need a proper once-over before the temperature drops.

This includes:

• Boiler servicing and combustion checks

• Verifying flow and return temperatures

• Ensuring pumps and valves are operating correctly

• Checking heat pump defrost cycles

• Confirming thermostats and zone controls are responding properly

A “winter HVAC inspection” not only prevents breakdowns, it ensures your heating system runs efficiently, keeping energy bills manageable during peak usage.

4. Review and Optimise Your BMS for Winter Settings

Think of your BMS (Building Management System) as the brains of the operation. When set up correctly, it can save serious energy over the winter period. When ignored… well, let’s not go there.

Key BMS checks for winter:

• Are heating schedules correct for how your building is actually used?

• Are setback temperatures realistic?

• Are holiday shutdown modes set for Christmas and New Year?

• Are deadbands (between heating and cooling) wide enough to avoid unnecessary overlap?

Energy-saving tip: If your building shuts down over the holidays, or even operates on reduced hours, adjusting BMS schedules can significantly reduce wasted heating. It’s one of the easiest ways to cut carbon and costs without affecting comfort.

Many sites don’t realise their BMS is still heating areas that don’t need it, or running ventilation at full speed when occupancy is low. A quick optimisation can pay for itself almost immediately.

5. Make Sure Your System Has a Winter-Ready PPM Visit

A proper winter PPM visit brings everything together. Engineers can spot warning signs early, test safety controls, check refrigerant levels, ensure pumps are lubricated, inspect electrical components, and confirm everything is running exactly as it should.

A winter-focused PPM typically includes:

• Full heating operation checks

• Verification of frost protection

• Inspecting external units for debris or ice risk

• Checking insulation on pipework

• Ensuring drain lines are clear and functional

• Reviewing system efficiency and energy usage

It’s preventative maintenance at its best, avoiding costly winter breakdowns when you need your systems the most.

At William Austin, winter PPMs are one of the most valuable visits we conduct each year. They keep systems reliable, efficient, and ready for whatever the UK weather decides to throw at us.

Final Thoughts: Winter Doesn’t Have to Catch You Off Guard

A winter-ready HVAC system is safer, more efficient, more reliable, and far more cost-effective. By following these five steps, and giving your equipment a bit of seasonal TLC, you’re setting your building up for a smooth, comfortable, and energy-efficient winter.

And if you need expert support, advice, or a winter PPM…

The team at William Austin is always here to help.

Written by Will Judd

Published: 20/11/2025