Fan Coil Units in London Apartments

Wix
Jul 9
3 min read

Updated: Aug 5

The Hidden System You Shouldn’t Ignore

When you step into a luxury London apartment, you're likely greeted by clean lines, clever design, and consistent indoor comfort. But hidden behind wardrobes, bulkheads or ceiling grilles is a vital piece of equipment most homeowners and tenants rarely think about: the fan coil unit (FCU).

These units quietly heat or cool your space — but if they’re not properly maintained, they can become inefficient, noisy, or even unhygienic. In this article, we explain what fan coils do, why they matter, and how our 6-monthly maintenance keeps your apartment running at its best.

What Is a Fan Coil Unit?

A fan coil unit is a compact system that draws in air, passes it over a coil filled with hot or chilled water, and then pushes the conditioned air back into the room through a grille.

In summer: chilled water cools the air.
In winter: warm water heats the air.

They don’t connect to outdoor units like air conditioners — instead, they rely on a central plant in your building. You’ll typically find a fan coil in each main room or bedroom of your apartment, but the unit itself is hidden behind ceiling panels or built-in joinery.

You only see the grille. The hard-working components are tucked away.

Why Do Fan Coils Need Servicing?

Just like a car, fan coils need periodic maintenance. At Maintain My Home, we carry out a 6-monthly service which includes:

1. RDU-45 Spraying of the Impeller

The impeller is the spinning fan that circulates air.
Over time, it gathers dust, bacteria and grime — especially in London’s urban environment.
We use RDU-45, a professional HVAC disinfectant spray, to clean and sanitise the impeller.

This prevents smells, bacteria build-up, and noisy operation.

2. Exercising the Valves

Fan coil valves open and close to let hot or chilled water into the coil.
In winter, your cooling valves may go unused for months.
We “exercise” the valves (turning them manually open and shut) to prevent sticking or seizure before summer returns.

This reduces the risk of the system failing just when you need cooling most.

3. Cleaning or Replacing the Filters

Fan coils draw in air and pass it through a filter to remove dust and particles.
Dirty filters mean:
Reduced airflow
Higher energy bills
Poor air quality

In London, where outside pollution is high, filters can get clogged quickly — especially on lower floors. Our standard service includes removal, cleaning, or replacement depending on their condition.

FAQs: Fan Coil Unit Maintenance

Q: Where is my fan coil unit located? Most are hidden in ceiling voids, above wardrobes, or inside built-in joinery. Only the grille is visible.

Q: Can I clean the filters myself? Not easily. Most apartments require tools or professional access to ceiling panels. It’s safer and easier to let our technicians handle this.

Q: Why does it smell when I turn on the cooling? This often comes from bacteria on the impeller. RDU-45 spraying eliminates the source of these smells.

Q: What happens if I skip maintenance? Your cooling or heating may underperform, make noise, or fail entirely — often during peak seasons when HVAC engineers are busiest.