Boiler Servicing & Maintenance
Full 21-point check, flue gas analysis and written report. Keeps your warranty intact, your bills down, and your home safe — booked in a single phone call.
£80+VAT
single boiler
21-Point
service
Gas Safe
certified
Same Week
appointments
Service Overview
An annual boiler service is a full mechanical inspection, clean, test and recertification of your gas appliance. To manufacturer schedule, it covers the burner, heat exchanger, combustion chamber, flue, condensate, controls, safety devices and gas tightness — finishing with a calibrated flue gas analysis to verify safe, efficient operation.
Every household with a gas boiler. Particularly critical for landlords (where it's a legal requirement on every let property), anyone with a manufacturer warranty in force (services missed will void it), and households relying on the boiler through a cold winter.
Annually, every year, without fail. Most manufacturers and the Gas Safe register recommend a service inside 12 months of install date, then annually thereafter. The best month is late summer or early autumn — services booked in October/November fill up quickly, and the worst time to find a fault is mid-January.
Three reasons. Safety: combustion faults can produce carbon monoxide, which kills silently. Warranty: every major manufacturer voids cover the moment a service is missed. Cost: a serviced boiler runs 5-12% more efficiently than a neglected one, paying for itself within the year on gas savings alone — before you factor in the £400-£900 repair bills a service typically prevents.
The Cost of Waiting
What happens when a boiler isn't serviced annually:
Our Process
01
One phone call. We confirm appliance brand, model and age, and offer the next available slot — usually within the week.
02
Casing off, full visual on heat exchanger, burner, fan assembly, controls and pipework.
03
Burner removed and cleaned, condensate trap flushed, pressure and gas tightness tested, controls and safety devices verified.
04
Calibrated flue gas analyser measures CO/CO₂ ratio at the flue — the only way to verify safe, efficient combustion.
05
Written service report, Gas Safe documentation, warranty record updated. Emailed within 24 hours.
Why Choose On-Tap
Service record meets every major manufacturer's annual service requirement — Worcester, Vaillant, Ideal, Baxi, all covered.
Clean combustion components mean every cubic metre of gas does more useful work — savings hit the next bill.
Most £900 emergency repairs start as £40 service-discovered issues. A service is preventative, not cosmetic.
Combustion analysis and CO check confirm the appliance is safe to run for another year.
Booked at a time that suits you, done in one visit, paperwork emailed afterwards.
If everything's fine, we'll tell you so. If something needs attention, you'll get a clear written quote — no pressure.
In Depth
Boiler 'services' offered cheaply online are often a 10-minute visual check and a sticker. Here's what a proper service to manufacturer schedule actually involves.
Casing removed. Visual inspection of burner, heat exchanger, combustion chamber, fan, ignition electrodes, pilot (if applicable), condensate trap, expansion vessel, pump, diverter valve and PCB. Burner removed and cleaned. Combustion chamber inspected for cracking or corrosion. Condensate trap removed, flushed and refitted. Heat exchanger inspected for fur, scale or deposit build-up. Where access permits, fins brushed clean.
Standing and working gas pressure measured against manufacturer specification. Gas tightness test on the supply pipework. Expansion vessel pressure checked and recharged if needed. System fill pressure verified. Pump performance checked. Electrical safety check on the appliance's earth bonding and supply.
Flue gas sample taken with a calibrated analyser. CO, CO₂, O₂ and combustion efficiency measured at the flue and recorded against manufacturer's acceptable range. Visual inspection of the full flue length where accessible, including joints, terminations and clearances. Any flue concern is flagged and quoted before any further work.
We offer single-visit annual services for homeowners and landlord packages where the service and CP12 can be combined into a single visit at a single price — no contract, no auto-renewal, no surprises.
£80+VAT for a single appliance at a standard residential property. Combined service + CP12 for landlords is £110+VAT.
Typically 45-75 minutes per appliance, depending on brand, age and condition. We'll always confirm a time window when we book.
Yes — in the right direction. A documented annual service by a Gas Safe engineer is a requirement of every major manufacturer's warranty. Skipping one usually voids cover.
We'll explain it, write a fixed-price quote, and let you decide. No pressure, no surprise charges. If it's a quick fix we can often do it on the same visit.
Yes — Worcester Bosch, Vaillant, Ideal, Baxi, Glow-worm, Viessmann, Potterton, Alpha and most others. Our accredited status with Worcester and Vaillant simply lets us extend their warranties on new installs.
August to October is ideal — engineer availability is good, and faults are caught well before winter. December and January are our busiest months and slots fill 2-3 weeks ahead.
Yes — single-visit annual services, plus landlord portfolio plans with reminder scheduling. Ask when you book.
Stevenage, Bedford, Luton, Milton Keynes, Hitchin, Flitwick, Biggleswade, Barton-le-Clay and across Bedfordshire and north Hertfordshire.
Related Services
A fixed-price quote in writing, a Gas Safe engineer on site, and the job done right first time.
