Standard combi service
Fixed price
Full Gas Safe service, flue gas analysis, written record, sticker, digital copy emailed.
Heating & Gas Services
Annual Boiler Servicing in Corbyfixed-price — keeps your warranty validlandlord CP12 certificates included
An annual service is the cheapest insurance you'll ever buy for your heating system. Keeps your manufacturer warranty valid, reduces gas consumption, catches small problems before they become winter breakdowns. Booked at a time that suits you.
- Fixed-price service
- Gas Safe registered
- Landlord CP12 same day
- Worcester Accredited Servicer
Fixed
Standard combi service price
10+
Manufacturer checks performed
Same day
CP12 issued
100%
Gas Safe registered
Boiler servicing — combi, system, regular, LPG & oil
What an annual service actually does — and why your warranty depends on it
An annual boiler service is a 45–60 minute thorough inspection: visual check of casing and combustion chamber, flue gas analysis to confirm clean combustion, gas pressure check at the inlet and burner, condensate trap clean, system pressure check, expansion vessel check, electrical safety check, controls test, and a written service record.
Almost every domestic boiler manufacturer requires annual servicing as a condition of the warranty — Worcester, Vaillant, Ideal, Baxi, Glow-worm, Viessmann all specify it. Skip a year, and the warranty can be voided. Service annually with a Gas Safe engineer, and you keep the warranty live for its full 5–12 year term.
On top of warranty validity, a service genuinely reduces gas consumption. A boiler running with a partially-blocked flue, dirty heat exchanger or out-of-spec gas pressure burns more fuel for the same heat output. Annual service typically cuts gas use by 5–10% versus an unmaintained boiler.
What happens if you wait
Skipped services kill warranties — and find faults the hard way
We've seen 4-year-old boilers with rejected warranty claims because the owner couldn't produce annual service records. The boiler was fine; the paperwork wasn't — and a repair that should have been free under warranty became a chargeable bill.
Carbon monoxide is the other reason to service. A blocked flue or cracked heat exchanger can leak CO into the home — colourless, odourless, and lethal at the right concentration. Annual flue gas analysis catches it.
- Manufacturer warranty void after a missed service — repair bills back on you
- Gas Safe certification gap for landlords — fines and prosecution risk
- CO leak from blocked flue or cracked heat exchanger — silent risk
- Inefficient combustion = 5–10% higher gas bills
- Small faults (worn condensate trap, dirty filter) compounding into failures
- Insurance refusal on heating-related water damage with no service history
Our process
From first call to job done — exactly what to expect
- 01
Visual inspection
Casing, flue terminal, condensate, gas connections, electrical isolation, pipework, controls all visually checked.
- 02
Combustion test
Flue gas analyser used at the flue. CO, CO2 and ratio recorded against manufacturer spec.
- 03
Internal checks
Casing removed, burner condition checked, heat exchanger inspected, condensate trap cleaned, electrical safety tested.
- 04
System checks
System pressure, expansion vessel charge, inhibitor test, magnetic filter clean if fitted, controls tested.
- 05
Documentation
Written service record, sticker on boiler, digital copy emailed. CP12 issued same day for landlords.
Why customers choose Reactive
No guesswork. No upsell. Just the work, done right.
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Keeps warranty valid
Manufacturer service requirements met to the letter. Documentation accepted by Worcester, Vaillant, Ideal, Baxi.
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Cuts gas bills
5–10% gas reduction typical on a serviced vs unserviced boiler over a heating season.
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Catches small problems early
Worn condensate trap, weak ignition, low expansion charge — fixed before they cause winter breakdowns.
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Booked at your convenience
Evening and Saturday slots available. Annual reminder sent so you never miss.
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Landlord CP12 included
Same-day Landlord Gas Safety Record (CP12) issued where applicable. Digital copy emailed.
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Carbon monoxide check
Flue gas analysis catches CO leaks early. Genuine safety value, not a sales pitch.
In detail
What's actually in a Gas Safe boiler service — checklist by checklist
A proper service is not 'a quick look'. It's a defined sequence of checks against the manufacturer's specification for that exact boiler model. Worcester, Vaillant and Ideal each publish their own service schedules; we follow them to the letter and document each step.
The headline check is the flue gas analysis. A calibrated analyser samples the flue gas and reports oxygen, carbon monoxide, carbon dioxide and the ratio of CO to CO2 — known as the lambda or excess air figure. Each manufacturer specifies a target range for these values. Outside the range means dirty combustion, partial blockage, or burner wear.
Beyond combustion, we check: gas inlet pressure, working pressure at the burner, expansion vessel pre-charge (a flat vessel is the #1 cause of mystery pressure loss), system inhibitor concentration, electrical safety (Class 1 earth continuity), condensate trap cleanliness, controls function (call-for-heat, hot water priority, frost protection), and the condition of all visible pipework and fittings.
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Combi boiler service
Standard 45–60 min. Plus DHW priority, plate heat exchanger flow rate, diverter check.
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System boiler service
Plus unvented cylinder G3 check (where Reactive installed it), expansion vessel + PRV.
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Regular (heat-only)
Plus open-vent / F&E tank check, pump performance test.
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LPG service
Same as gas plus tank-to-property pipework check, regulator and changeover.
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Oil boiler (OFTEC)
Different process — burner strip-down, nozzle replacement, electrode reset, smoke and combustion.
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Landlord CP12
Statutory check for rented properties. Issued same day, digital + paper copy provided.
Honest pricing
How much does a boiler service cost in Corby & Northants?
Pricing depends on boiler type and whether a CP12 landlord certificate is required. Annual servicing plans cut the per-year cost.
System or regular boiler service
Fixed price
All of the above plus expansion vessel, PRV and unvented cylinder G3 check where applicable.
Landlord CP12 + service
Fixed price
Full service plus same-day issue of Landlord Gas Safety Record (CP12). Multiple appliances priced on request.
What changes the price
- Boiler type (combi, system, regular, LPG, oil)
- Single or multiple gas appliances
- Whether CP12 landlord certificate required
- Distance from Corby (Ring 1 — no travel charge)
- Annual plan vs. one-off service
- Magnetic filter clean if fitted (included free)
Free, fixed-price quote — no obligation, no callout fee.
Get my fixed priceAreas covered
Local cover across Northants & Rutland
Servicing covers everywhere we install — Corby, Kettering, Wellingborough, Desborough, Rothwell, Oundle, Oakham, Market Harborough and the surrounding villages. Annual reminder sent automatically once you're on our service list.
Who'll be doing the work
The Reactive engineering team
We personally service every boiler we install — annual service plus 12-year warranty registration on Worcester, 10-year on Vaillant. The boilers we install we still know intimately when we come back to service them.
- Gas Safe Registered
- Worcester Accredited Servicer
- Vaillant Service approved
- OFTEC for oil boilers
- Unvented Cylinder G3 Certified
FAQs
Questions we actually get asked
Anything not covered here? Pick up the phone — straight talk, no salesperson in the middle.
Call 07488 883576Ready when you are
Keep the warranty live. Book your service.
Fixed-price annual service, Gas Safe certified, manufacturer warranty maintained, landlord CP12 same day.
Last updated May 2026 · Reactive Gas Heating and Plumbing Services Limited · 9 Rutherford Court, Corby NN17 4SJ · Gas Safe Registered · OFTEC Registered · Checkatrade Verified