5-year compressor warranty on every unitWilliams range held in UK stock+44 7426 370650
Williams — UK distributor

Cool in July.
Warm in January.
One quiet box.

Williams inverter air conditioning and air source heat pumps, held in UK stock. Buy the unit alone, or have our engineers fit it — most installs finished in a day.

Shop the rangeWhich size do I need?
A+++
Top energy class
19 dB
Quieter than a whisper
5 yr
Compressor warranty
R32
Refrigerant throughout
5-year compressor warranty
5 years on the compressor, 3 on the indoor unit — registered automatically.
Supplied or fully installed
Buy the unit alone, or let our F-Gas engineers fit it.
The full Williams range
Nine A+++ inverter series, held in UK stock.
R32 refrigerant throughout
Lower GWP, and compliant beyond 2030.
Best sellers

What Britain is actually buying

Ranked by units shipped this season. Every one is in stock today.

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The range

Three ways to condition a building

Everything we sell runs on inverter technology and R32, and everything is held in UK stock. The difference is where the box goes.

Wall-mounted split
For the home

Wall-mounted split

The everyday hero. One indoor unit, one outdoor unit, heating and cooling from a single system all year round.

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Ceiling cassette
For business

Ceiling cassette

Four-way discreet distribution recessed into a suspended ceiling. The standard for offices, retail and hospitality.

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Concealed ducted
Invisible

Concealed ducted

Completely invisible. The unit hides in the ceiling void and only slim linear grilles are ever seen.

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Sizing

Get the capacity right first

An undersized unit runs flat out and never quite gets there. An oversized one short-cycles, wastes money and leaves the room clammy. Two minutes here saves both.

8 m²140 m²
Room type
Estimated load
8,800 BTU/h
Choose a unit rated
9,000 BTU
≈ 2.6 kW
See matching unitsAsk an engineer instead

A guide only. Awkward rooms, poor insulation and open-plan layouts change the answer — send us a photo and we will size it properly, free.

Who we are

The distributor, not a reseller

Reliable Williams is the United Kingdom distributor for Williams — the same team that has supplied the brand across southern Europe since 2012. Stock sits in our own Surrey warehouse, not on a container somewhere.

That matters when something goes wrong. Warranty parts ship from the same building your unit did, usually the same day, and the person who answers the phone can see your order.

We sell supply-only to trade and to competent installers, and we install directly across the South East and the Midlands with our own F-Gas registered engineers.

Our warehouse
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Years with the brand
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Units supplied
0
Williams series in stock
0.0/5
Average customer rating
Journal

Advice worth reading before you buy

All articles
Buying advice·

Don't buy for this summer alone: the cheap air conditioning trap

The unit that costs £180 less today can cost £90 a year more to run, and be scrap in six summers. Here is the arithmetic nobody does at the point of sale.

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Buying advice·

SEER, SCOP and the energy label: what the numbers actually mean

Two units both say A+++. One has a SEER of 8.6, the other 6.1. That gap is roughly £70 a year, and the label alone will never tell you.

Read more
Industry·

Why British homes are finally buying air conditioning

For decades the answer was a fan and an open window. Three consecutive record summers and a change in how we build houses have quietly ended that.

Read more
Get in touch

Tell us the room, we'll tell you the unit

No online checkout, no pressure — just send the details and we come back with the right Williams model and a price. Or call and speak to someone who has actually fitted one.

+44 7426 370650[email protected]

Request a price

Tell us the room and roughly its size and we'll come back with the right unit and a price. Photos always help.

Prefer to browse first? See the full range