Air Conditioning vs Gas Central Heating: Which Is Cheaper to Run?

For an air-to-air heat pump, divide the electricity unit price by its average coefficient of performance, or COP, over the period being considered. For a boiler, divide the gas unit price by an appropriate efficiency expressed as a decimal. Both calculations give a fuel cost per useful kilowatt-hour of heat.

An efficiency assumption of 0.90 means 90% of the gas energy becomes useful heat within the chosen calculation boundary. It is an illustration, not a claim about your existing boiler. Controls, cycling and distribution losses can affect the actual result.

Ofgem’s tariff tables give average Direct Debit unit rates for Great Britain of 26.32p/kWh electricity and 7.97p/kWh gas for 1 October–31 December 2026. Rates vary by region, payment method and contract; these are not a quotation for your home.

At an assumed COP of three, heat-pump fuel cost is 26.32 ÷ 3 = 8.77p per useful kWh. At an assumed boiler efficiency of 0.90, gas heat costs 7.97 ÷ 0.90 = 8.86p. These rounded results are close enough that different assumptions could reverse the comparison.

Using those example prices, the heat pump needs an average COP above approximately 2.97 to beat the assumed boiler on fuel cost alone. That follows from electricity price multiplied by boiler efficiency, divided by gas price.

Do not use the best COP printed in a brochure as a year-round guarantee. Request seasonal and cold-weather information for the proposed equipment. Our energy-price guide explains why your actual tariff matters more than a headline annual bill.

Retaining gas for cooking or hot water normally means retaining its standing charge. Do not count that charge as an avoided cost just because one room is heated electrically. Removing a gas connection is a separate decision with practical and financial consequences.

Standard air-to-air systems warm room air rather than supplying existing radiators or tap water. Include whatever arrangement remains necessary for bathing, other rooms and colder periods. Comparing space heating alone cannot establish the total cost of replacing a household’s full heating and hot-water provision.

Heating an occupied home office without warming unused rooms may reduce demand, but that is a zoning benefit as well as an equipment comparison. Gas controls can also provide zoning, depending on the existing system. Record room temperatures and operating hours before estimating a saving.

Use a range of heat-pump performance assumptions rather than a single optimistic number. The heating-cost worksheet helps separate heat demand, fuel price, efficiency and costs that stay unchanged.

Installation, maintenance, equipment life, noise and summer cooling all belong in the decision. Cooling is an additional electricity use, not a free consequence of efficient winter heating. A small fuel saving may not repay an installation undertaken solely to reduce bills. Keep any estimated payback separate from the value you place on more comfortable rooms.

Aircon Elite’s heating installation service covers air-to-air systems within its air conditioning range, not gas boiler installation. Ask for a property-specific assessment that explains the proposed comfort benefits and the limitations as clearly as the running-cost estimate.