Boiler Servicing

What does a boiler service actually include?

A proper boiler service includes flue gas analysis with a calibrated analyser, gas rate and burner pressure checks against the manufacturer's data, inspection of seals, electrodes and the condensate trap, a clean of the magnetic filter, proving of safety devices, a flue and ventilation check, and the Benchmark service record updated.

The flue gas analysis is the heart of it, and it's what separates a service from a glance. The analyser samples the combustion products and reports the CO and CO2 figures and their ratio — numbers that reveal a fouling burner or a drifting gas valve long before a fault code ever would. We check them against the manufacturer's tolerances and adjust where the boiler allows it. No analyser print-out, no evidence the combustion was ever measured; it's a fair thing to ask any servicing firm to show you.

Beyond the boiler itself we check system pressure, the expansion vessel charge, the condensate run and your carbon monoxide alarm. Fifteen-minute services skip most of this list — that's how they fit six to a morning.

How much does a boiler service cost in Surrey?

A full boiler service costs £90–£110 at Surrey Heating, depending on boiler type — a straightforward combi sits at the lower end, system boilers with cylinders and back-boiler units at the upper. The price includes the flue gas analysis, filter clean and Benchmark logbook entry; there are no attendance fees on top.

You'll see cheaper numbers advertised, and the arithmetic behind a £45 service deserves daylight: at that price the visit must be short, and short visits are visual checks, not services. You'll also see dearer routes, chiefly cover plans costing £200+ a year whether anything needs doing or not. The £90–£110 independent service with proper test equipment is the value position, which is why it's the one we occupy. And the service price is the service price — anything found during it is quoted separately and the choice is yours, because our service is not a loss-leader that must earn its keep through discovered work.

Do I really need a boiler service every year?

Yes, for three independent reasons: the manufacturer guarantee requires an annual service to stay valid; combustion safety — including carbon monoxide risk — can only be verified by measurement; and small faults caught at a service cost a fraction of the winter boiler repairs they become.

The guarantee condition is contractual, not advisory. Manufacturers' terms require annual servicing by a Gas Safe registered engineer, evidenced in the service record, and claims assessors do check. On a boiler carrying a 10 or 12-year guarantee, roughly £100 a year protects a four-figure appliance for its whole insured life — it's the cheapest part of owning the thing.

The practical case is just as strong locally. Surrey's very hard water means scale accumulates in every heat exchanger every year; the service catches kettling early, and a clean magnetic filter keeps sludge from circulating. Boilers also fail when worked hardest — the first cold week — and a September service finds the perished seal, the lazy electrode and the vulnerable condensate run before January does.

What's the difference between a boiler service and a gas safety check?

A gas safety check (the landlord's CP12) verifies that an appliance is safe: gas tightness, flue operation, ventilation, safety devices. A boiler service includes those safety elements but goes further — combustion analysed and adjusted, components inspected and cleaned, the filter emptied, and the manufacturer's service record completed.

The distinction matters most to landlords, because the law requires the annual Landlord Gas Safety Record for tenanted property but a CP12 alone does not satisfy the boiler manufacturer's servicing condition — so a rental property boiler can be legally compliant and out of guarantee at the same time. The efficient answer is to combine both in one visit, one engineer, one piece of scheduling: we do the safety record for every gas appliance in the property and the full service on the boiler, and price the combination accordingly. For homeowners the takeaway is simpler: a bargain "safety check" isn't a service, won't protect your guarantee, and leaves nothing cleaned, adjusted or recorded in the Benchmark logbook.

Why does hard water make servicing matter more in Surrey?

Surrey's water is very hard — typically over 300 ppm of dissolved calcium and magnesium — and every litre your boiler heats leaves a little of it behind as limescale. Scale on the heat exchanger insulates it, cuts efficiency, causes kettling and shortens the component's life, which makes the annual service unusually valuable here.

The service is where scale gets caught while it's still cheap: early kettling responds to a chemical clean and fresh inhibitor at modest cost, while advanced scaling ends in the most expensive repair on the boiler's parts list. The magnetic filter clean matters for the same reason — it pulls the circulating debris out of the system before it settles somewhere expensive. We also check your scale defences — inhibitor concentration and any scale reducer on the cold feed — because manufacturers can decline guarantee claims for scale damage where no protection was fitted, a paragraph of small print that matters more in KT8 than almost anywhere.