Air conditioning servicing
and maintenance
An annual service keeps the manufacturer warranty valid, stops the smell that starts in year two, and catches the small refrigerant leak before it becomes a new compressor. Any make, including systems we did not install.
- Domestic annual service from 95 pounds plus VAT
- Any make, any age, including other installers' work
- Written record of every reading, for your warranty
- Commercial contracts with fixed response times
Second and subsequent unit on the same visit: 55 pounds plus VAT each.
- Electro Heating LimitedCompany 12609754, registered in England and Wales
- NICEIC and Gas Safe registeredHeld by the parent company
- MCS certifiedFor heat pump and solar work
- 10+ years in LondonSame engineers, same company
Air conditioning should be serviced once a year, and a domestic service in London costs 95 to 140 pounds plus VAT for one system.
Almost every manufacturer warranty is conditional on documented annual servicing, so the service is usually cheaper than the warranty it protects. Book it in April or May, before the first hot week fills every diary in London.
What happens in the two hours we are there
A service is not a look and a wipe. These are the twelve things we do, and the order matters because half of them only make sense once the system is running.
| Step | What it prevents |
|---|---|
| Filters cleaned or replaced | Lost airflow, higher bills, coil freezing |
| Indoor coil deep cleaned | The smell, and a 20 percent capacity loss |
| Blower wheel cleaned | Noise, poor throw, dust blown into the room |
| Condensate tray and drain flushed | Water dripping down your wall |
| Outdoor coil washed | High head pressure and a shortened compressor life |
| Electrical connections checked | Burnt terminals, the most common fire risk |
| Operating pressures measured | Finding a leak while it is still small |
| Temperature split measured | Proving the system actually performs |
| Refrigerant charge verified | Running low, which destroys compressors |
| Fan motor and bearings checked | The noise that starts in year four |
| Controls and all modes tested | Faults you would only find in December |
| Written record issued | A warranty claim that gets accepted |
What it costs
| Service | Price | Included |
|---|---|---|
| Domestic annual service, one system | £95 plus VAT | Full 12 point service and written record |
| Each additional unit, same visit | £55 plus VAT | Same service, no second call-out |
| Deep clean, heavily soiled indoor unit | £160 plus VAT | Chemical coil clean, blower wheel removed |
| Commercial system, per unit | £110 plus VAT | Plus F-Gas leak check and log where required |
| Annual contract, 2 visits | From £220 plus VAT | Priority response and no call-out fee on faults |
Why the smell happens, and why deodoriser makes it worse
The indoor coil is cold, wet and dark for four months of the year. That is an ideal surface for biological growth, and once it establishes, the smell arrives about thirty seconds after the unit starts, then fades. That timing is the giveaway.
A spray can pushes scent through the coil and leaves a residue that the growth then feeds on, so the smell returns worse. The fix is mechanical: pull the covers, clean the coil properly with the right chemistry, remove and wash the blower wheel, and flush the drain so the tray is not sitting in standing water for the rest of the year.
F-Gas: what actually applies to you
UK F-Gas rules set leak-check duties by system size, measured in tonnes of CO2 equivalent rather than in kilograms, so the same weight of two different refrigerants gives different answers.
| System size | Leak check | Typical example |
|---|---|---|
| Under 5 tonnes CO2e | No legal duty | Nearly all domestic single splits |
| 5 to 50 tonnes CO2e | Every 12 months | Larger multi-split, small commercial |
| 50 to 500 tonnes CO2e | Every 6 months | Office VRF systems |
| Over 500 tonnes CO2e | Every 3 months, plus leak detection | Large commercial plant |
The duty sits with the operator of the equipment, which for a leased office is normally the tenant rather than the landlord. Records must be kept for at least five years. If a system is below the threshold the check is still worth doing, because a slow leak costs you efficiency long before it causes a breakdown.
Servicing questions
How often should air conditioning be serviced?
Once a year for a domestic system, and every six months for a commercial one that runs all day. Almost every manufacturer warranty requires documented annual servicing, and a warranty claim on an unserviced system is normally refused.
The best month is April or May, before the first hot week. Everyone calls in the third week of June and nobody can get a slot.
What does an air conditioning service actually include?
Filter clean or replace, indoor coil and blower wheel clean, condensate tray and drain flush, outdoor coil wash, electrical connections checked and tightened, operating pressures and temperature split measured, refrigerant charge verified, and controls and modes tested.
You get a written record of the readings, which is what a manufacturer asks for if you ever make a warranty claim.
Do I legally need an F-Gas leak check?
Only above a size threshold. Systems containing 5 tonnes of CO2 equivalent or more must be leak checked at least every twelve months by a certified person, and records kept. Almost every domestic single split sits below that threshold, so the check is good practice rather than a legal duty.
Most commercial multi-split and VRF systems are above it, and the duty falls on the operator of the equipment, which usually means the business occupying the building rather than the landlord.
My air conditioning smells. What is that?
Almost always biological growth on the indoor coil and in the condensate tray, where a dark, wet, warm surface has been left to itself for a couple of years. It is the single most common reason people call us about a system that is otherwise working.
A proper coil clean and drain flush fixes it. A spray can of deodoriser masks it for a fortnight and makes it worse, because the residue feeds the growth.
Will you service a system another company installed?
Yes, any make and any age. We do a lot of it. What we will not do is sign off a system we can see is unsafe or badly installed without telling you what is wrong with it in writing first.
If the original installer left no commissioning record, we start one, which puts your warranty position back on a documented footing.
Book a service before the first hot week
One visit a year keeps the warranty valid, the bills down and the smell away. Any make, any age, including systems another company installed.