Repair your boiler.

A boiler repair in the UK typically costs £90–£400, depending on the fault, the boiler model, and whether parts need to be ordered. The most common faults are pressure loss, faulty diverter valves, broken pumps, and frozen condensate pipes — all fixable in a single visit if the engineer carries common parts.

Any boiler work involving the gas supply must be done by a Gas Safe registered engineer. Don't be tempted by handyman quotes for boiler work — illegal, unsafe, and invalidates your insurance.

Common boiler faults and what they cost

Standard callout: £55–£90. Same-day or weekend callouts add £30–£60.

Fault codes — what they mean

Modern boilers (Worcester, Vaillant, Baxi, Ideal, Glow-worm) display fault codes when something's wrong. Common codes:

• F22 / F28 (Vaillant) — low pressure, top up the system to 1.0–1.5 bar via the filling loop.
• EA / E1 (Worcester Greenstar) — flame failure or ignition fault. Often a frozen condensate pipe in winter; otherwise needs an engineer.
• F1 (Baxi) — low pressure. Top up via filling loop.
• F4 / F5 (Ideal) — flame failure or fan failure. Engineer required.
• D5 / D6 — temperature sensor faults; engineer required.

Look up your specific code in the manual or on the manufacturer's site before booking — some are user-fixable in 2 minutes.

Frozen condensate pipe — the winter classic

Modern condensing boilers produce a small amount of acidic water as a by-product, drained through a plastic pipe to outside. In freezing weather, that pipe can freeze solid, the boiler senses the blockage, and shuts down with a fault code. Fix: pour warm (not boiling) water along the external pipe until you hear it flow, then reset the boiler.

To prevent recurrence: lag the external pipe with foam insulation, or have it re-routed inside the building if possible. Many engineers can do this as part of a service.

Repair vs replace

Use the 50% rule: if the repair quote is more than half the cost of a replacement boiler installed (£2,500–£4,000 for a typical UK combi swap), replace. A 12-year-old boiler with a heat exchanger fault is on the wrong side of that line. A 5-year-old boiler with a £250 pump fault is well clear.

Other replacement triggers: noisy operation that's gradually worsening, frequent fault codes, parts becoming hard to source (most boilers under 10 years have plentiful parts; over 15 years, you may struggle).

Things people often miss

• Manufacturer warranty — most boilers have 5–12 year manufacturer warranties. If it's still under warranty, the manufacturer's engineer should fix it for free; don't pay an independent in that window.
• Service plans — British Gas, EDF and similar offer monthly cover plans. Worth it for older boilers (over 8 years), borderline for newer ones — do the maths against expected repair cost.
• Powerflushing — sludge build-up in old radiators causes pump failures and cold spots. A professional powerflush (£400–£800) extends boiler life and improves heating performance — worth pairing with a major repair.
• Annual service — keeping a boiler serviced yearly maintains the manufacturer warranty and catches small faults early. £75–£140 a year is cheap insurance.
• Magnetic system filter — devices like the MagnaClean or Adey Filter capture iron oxide sludge before it reaches the boiler. £200–£350 fitted; most modern installs include one as standard.

Frequently asked questions

Want a local pro to handle this? A Gas Safe registered engineer with experience on your boiler brand will diagnose and fix most faults in a single visit. Don't try to repair gas appliances yourself — illegal, dangerous, and not covered by insurance.