How Much Does It Cost to Replace a Hot Water Cylinder?
£800 – £2,200
supply and fit
Hot water cylinder replacement costs between £800 and £2,200 supply and fit, depending on whether you are replacing a vented copper cylinder or upgrading to an unvented pressurised system. Unvented cylinders cost more to supply and require a G3-qualified engineer, but they deliver mains-pressure hot water to every outlet in the home.
Average cost
£800 – £2,200
supply and fit
Prices vary by region, property type and tradesperson. Always get at least two quotes.
What affects the price?
Cylinder type - a standard vented copper cylinder costs £300-£600; an unvented cylinder costs £600-£1,200 for the unit alone
Cylinder capacity - a larger capacity cylinder for a family home costs more than a smaller unit for a flat
Access and location - cylinders in airing cupboards are straightforward; those in lofts or below-ground plant rooms add labour time
Additional components - expansion vessels, pressure relief valves, and immersion heaters are often replaced at the same time for reliability
Labour vs materials
Labour for a cylinder replacement typically runs £300-£600 depending on complexity. For unvented cylinders, a G3-qualified engineer must carry out the work - always verify this qualification.
Repair or replace?
A hot water cylinder over 15-20 years old with a failing thermostat or immersion element is often better replaced than repaired, especially if it is losing heat overnight due to poor insulation.
Questions to ask your tradesperson
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