Keep your boiler running safely and your warranty intact. Gas Safe registered engineer based in Stowmarket.
A boiler service isn't just about ticking a box. A qualified Gas Safe engineer will check every part of the system that can degrade or fail — catching problems early before they become expensive callouts or dangerous faults.
Most boiler manufacturers require annual servicing by a Gas Safe registered engineer to keep the warranty valid. Miss a service and you may find yourself outside the warranty if something goes wrong.
I carry out boiler services across Stowmarket and mid-Suffolk. As a sole trader, every job is done by me personally — not passed to a subcontractor.
Standard annual boiler service
Boiler service + CP12 Gas Safety Certificate combined in one visit — saving you £50.
Book the landlord package →Landlords are legally required to have all gas appliances in rented properties checked annually by a Gas Safe registered engineer.
I can carry out the boiler service and the safety inspection in a single visit, issuing the Gas Safety Record (CP12) on the day.
Which? Trusted Trader — independently vetted and verified. View my listing
I arrive with the manufacturer's service documentation for your specific boiler model. Before I touch anything, I run the boiler briefly and observe how it's operating — flame picture, burner ignition, and how the controls respond. This gives me a baseline before I start stripping it down.
Isolating the gas supply and removing the casing. Once I've noted the running condition, I isolate the gas supply and remove the outer casing. With the casing off, I work through the internal components methodically.
Heat exchanger and burner. The heat exchanger is where combustion gases transfer heat to the central heating and hot water circuits. Over time, debris and combustion residues accumulate here, reducing efficiency and affecting combustion quality. I inspect it visually and clean it as required. The burner is removed, checked for distortion or blockage, and cleaned. The ignition electrodes — which provide the spark to light the burner — are checked for condition, gap, and signs of carbon build-up. Worn or incorrectly gapped electrodes cause unreliable ignition; I replace them if they're outside acceptable limits.
Condensate trap. Condensing boilers produce acidic condensate as a by-product of efficient combustion. The condensate trap can collect debris and block over time, triggering lockouts. I check it's clear and that the condensate pipework is draining freely.
Flue integrity check. I check the flue throughout its accessible length for correctly sealed joints and any signs of damage or deterioration. A compromised flue is a carbon monoxide risk. I also verify the flue termination is clear and correctly positioned.
Flue gas analysis. Using a calibrated combustion analyser, I measure carbon dioxide (CO₂) and carbon monoxide (CO) levels in the flue gases. These are compared against the manufacturer's published service data for your specific boiler to confirm combustion is within safe and efficient parameters.
Safety devices. I test the boiler's safety controls — including the overheat thermostat and any pressure-related safety devices — to confirm they're functioning as intended.
System pressure. I check the system pressure is within the manufacturer's recommended range and re-pressurise via the filling loop if needed.
Service record. Once everything is in order, I reinstate the casing, run the boiler to confirm normal operation, and complete the service record. You receive a copy on the day.
System pressure that drops repeatedly doesn't always mean there's a leak. The expansion vessel contains a rubber diaphragm that absorbs pressure changes as the heating system heats and cools. When the diaphragm fails, the vessel loses its pre-charge and the system pressure spikes during heating then falls back. Left unchecked, this puts repeated stress on the pressure relief valve and can cause it to weep. I check the vessel pre-charge pressure as part of every service.
Corrosion within the heating system produces iron oxide particles — commonly called magnetite or sludge — which circulate and settle in the boiler's heat exchanger, pump, and radiator bases. Heavy build-up restricts flow, reduces efficiency, and accelerates component wear. If I find significant contamination during a service, a power flush is worth considering before it causes more expensive damage downstream.
The condensate trap on a condensing boiler collects the acidic water produced during efficient combustion. Debris and biofilm build up over time and block it, causing the boiler to lock out with an error code. It's a straightforward fix during a service if caught early — more of a nuisance if the boiler has already stopped working on a cold morning.
The ignition electrodes erode gradually with use. The ceramic insulators can also crack or accumulate carbon deposits that interfere with the spark. A worn electrode set causes unreliable ignition, repeated lockouts, or a poor flame signal. Because this is a common wear item, I carry replacement electrodes for most boiler models and can swap them on the same visit.
Every boiler has a specified inlet gas pressure range. Supply pressure that's too low — typically caused by an undersized regulator or a partly restricted meter — means the boiler can't combust efficiently and may lock out under high demand. I measure inlet gas pressure at the boiler during every service and record whether it falls within the manufacturer's specified range.
Worcester Bosch, Vaillant, Baxi, and Ideal all require annual servicing by a Gas Safe registered engineer as a condition of their manufacturer warranty. Miss a year and you risk the manufacturer declining a warranty claim on the grounds that the boiler hasn't been maintained to their schedule. I'm a Worcester Bosch Accredited Installer and Vaillant Accredited Installer, so I'm familiar with the specific service requirements for both brands. For Baxi and Ideal I carry the same detailed knowledge from years of working on their ranges.
Late summer or early autumn — August to October — is the best time to book. Availability is better, and any issues can be sorted before you actually need the boiler running reliably. Leaving it until December or January means booking into the busiest period of the year. If something needs a part, you're waiting for it in a cold house rather than getting it sorted at your convenience beforehand.
"We have used Nick for the install of a new boiler and the subsequent annual maintenance and have always found him to be courteous, professional, on time and tidy. I recommend using Nick for both gas related work but also general plumbing."
Annual servicing keeps your boiler running safely and efficiently. Most manufacturers require it to keep the warranty valid. A Gas Safe engineer checks the heat exchanger, burner, flue, safety devices, and gas pressure — catching small issues before they become expensive breakdowns.
A full boiler service includes a visual inspection of the boiler and flue, checking gas pressure and flow, inspecting the burner and heat exchanger, testing safety devices and controls, checking for leaks or corrosion, and a flue gas analysis to confirm safe combustion. You'll receive a service record at the end.
Landlords are legally required to have all gas appliances checked annually by a Gas Safe registered engineer. The resulting certificate — commonly called a CP12 or Gas Safety Record — must be provided to tenants within 28 days and kept for two years. I can carry out the service and the safety check in a single visit.
A standard annual boiler service is £100. A combined boiler service and landlord gas safety certificate (CP12) is £150 — saving £50 on both done separately. All prices include checks, flue gas analysis, and a service record.
A standard boiler service typically takes between 45 minutes and an hour and a half, depending on the boiler model and what I find on the day. If the condensate trap needs clearing or the electrodes need replacing, it takes a little longer. I'll let you know if anything significant comes up before carrying out any additional work.
Yes — someone over 18 needs to be present throughout the visit. I'll need access to the boiler, any external flue termination points, and, on older properties, the gas meter. If you're a landlord, you don't need to be there yourself as long as your tenant is home and aware of the appointment.
I'll explain what I've found in plain terms and give you a clear idea of what it will cost to fix. Minor items — such as worn electrodes — I'll often carry parts for and can sort on the same visit. For anything more significant I'll provide a written quote before any further work is agreed. If the fault makes the boiler unsafe to operate, I'll follow the Gas Industry Unsafe Situations Procedure and advise you accordingly.
Yes. I service older back boilers and non-condensing boilers as well as modern condensing units. Older boilers often have more worn components and reduced efficiency. I'll give you an honest assessment of the boiler's condition and remaining serviceability, including whether replacement might be worth considering.