Warm Air Heating Service: Cost and What’s Included (2026)

What a warm air service involves

The engineer needs to be Gas Safe registered with the warm air category, which is separate from the boiler qualification. With the casing off, a proper service covers:

• The heat exchanger inspected for cracks and corrosion. A cracked heat exchanger can let combustion gases into the air that’s blown round the house. It’s the most important check on the visit.
• The burner cleaned and checked, and the gas pressure and flame set to the manufacturer’s figures
• The circulating fan cleaned and checked, including its bearings and the fan delay control
• The flue checked for leaks and a flue gas analysis on newer models
• The overheat and safety cut-outs tested
• The return air filter cleaned or replaced
• On combined units that heat your hot water too, the water side checked as well

What affects the cost

A warm air service costs more than a gas boiler service. Few engineers hold the warm air qualification, the heat exchanger inspection takes time, and older units take longer to strip down and clean. The price for your unit depends on:

• The make, model and age of the unit
• Whether it heats your hot water as well as the house, as a combined unit has a water side to check too
• How easy the unit is to get at, and how much cleaning the fan and filter need
• Whether it’s a one-off service or part of a service contract

What to check before you book

Ask whether the engineer is Gas Safe registered for warm air, and whether the visit includes the heat exchanger inspection and the safety cut-out tests. A visit without those isn’t a full service.

Have the make and model to hand when you ring. They’re on the data badge, which is usually inside the front panel.

Service contracts for warm air units

Most boiler cover plans don’t include warm air units, so check the small print before you buy one. A service contract from a warm air firm is the alternative.

Ours includes the annual service and up to three priority call-outs a year, with fault finding on those visits. Parts aren’t included, and any repair is priced before it’s done. There’s a single-unit plan, and a two-unit plan for properties with two separate units, with discounts for landlords with more than one property.

Getting a price from Plumbusters

We service warm air units of any make across Kent, London, Essex, East Sussex, Surrey and Berkshire. Most are Johnson & Starley, from current WarmCair models back to Economaire and Modairflow units. Ring 01622 474008 or request a call back with the make and model, and we’ll give you a price for a one-off service or a contract.