Boiler Service Cornwall

What a boiler service includes

A service is a test, not a glance. On a gas appliance the engineer should carry out and record the following, and show you the readings at the end:

• Combustion analysis with a flue gas analyser, against the manufacturer's stated ratios.
• Gas tightness and operating pressure — the supply as well as the appliance.
• Burner, heat exchanger and condensate trap inspected and cleaned.
• Safety devices and controls tested, including the flame supervision device and pressure relief.
• Ventilation and flue checked, including the termination outside and the flue seals.
• System checks — pressure, expansion vessel charge, inhibitor level and the magnetic filter if one is fitted.

Oil appliances follow the same principle with different specifics: nozzle and filter changes, combustion set to the manufacturer's figures, and the tank, line and fire valve inspected. LPG sits with gas. A heat pump gets its own annual check — refrigerant circuit, flow rates, strainer, controls and the recorded performance against design.

Why the annual date matters more than most people think

Two reasons beyond safety. First, manufacturer warranties almost always require an annual service by a qualified engineer, recorded. A ten-year warranty is worth nothing at year six if the service record has a gap in it. Second, if you let the property, the annual check is a legal duty, not a recommendation — see the landlord section below.

The third reason is money: a boiler that is short-cycling, running rich, or fighting a clogged filter burns more fuel every week until someone measures it. In an off-gas home on oil, that is the most expensive fuel in the county being wasted.

Landlord gas safety checks in Cornwall

Under the Gas Safety (Installation and Use) Regulations 1998, a landlord must:

• have every gas appliance and flue they provide checked every 12 months by a Gas Safe registered engineer;
• give a copy of the record to existing tenants within 28 days of the check;
• give a copy to new tenants before they move in; and
• keep records for two years.

The safety check and a service are not the same thing — the check confirms the appliance is safe on the day, the service maintains it — but they are normally done in one visit, which is what most Cornwall landlords ask us for. Holiday lets and second homes are covered by the same duty where gas appliances are provided.

Service, repair or replace?

The honest decision points, in the order we work through them at the visit:

• Under warranty and serviced? Repair, and keep the record straight.
• Out of warranty, single fault, parts available? Usually repair — a pump, a diverter valve or a fan is rarely worth replacing a boiler over.
• Repeat faults, scarce parts, or past ten years? Compare the repair against replacement, and against changing the heat source entirely.
• Oil or LPG, off the gas grid? Get the heat pump comparison before you commit to another fossil-fuel boiler: the Boiler Upgrade Scheme pays £9,000 until March 2027 where you replace oil or LPG and have no mains gas connection, and £7,500 otherwise. See heat pumps Cornwall and the Boiler Upgrade Scheme in Cornwall.

If replacement is the answer, our boiler installation page covers the options and the boiler replacement guide walks through sizing and controls.

What actually goes wrong in Cornish homes

• Frozen condensate pipes in a cold snap — the most common winter no-heat call, and usually preventable with a lagged or larger-bore external run.
• Pressure loss from a leaking expansion vessel or a weeping radiator valve; a pressure gauge that needs topping up monthly is a fault, not a chore.
• Sludge and poor water quality — the cause of cold-at-the-bottom radiators, noisy heat exchangers and early pump failure. A magnetic filter and the right inhibitor dose is the cheapest protection in heating.
• Oil tanks and lines — water ingress, sludge in the tank base and tired fire valves; found in a service, expensive as a breakdown.