Book an annual boiler service with an RGI‑registered engineer who performs a combustion analysis and hands you a signed service report. That single decision protects your household from carbon monoxide risk, keeps your boiler running efficiently, and preserves any manufacturer warranty. Expect the visit to run 30 to 90 minutes and to cost within a fair, transparent range, paid only once you’ve seen the readings and paperwork.
TL;DR:
- Only a registered gas installer should perform boiler servicing, and verifying their registration number before work begins is crucial for safety.
- A proper service includes a combustion analysis with a clear CO and CO2 reading, which is vital for detecting dangerous gas leaks.
- Costs vary based on season, boiler type, and fault discoveries, with independent engineers often offering lower rates than branded service plans.
- A thorough service takes 30 to 90 minutes, with a signed report and combustion analysis being essential for safety and warranty validation.
- Always ask for a signed, detailed service report and keep a photo record to ensure safety, warranty coverage, and proper documentation for future reference.
Table of Contents
- What does a boiler service actually include?
- Who is legally allowed to service a gas boiler?
- How much does a boiler service cost in Dublin?
- How long does a boiler service take?
- What should you ask before and during the visit?
- Why the service report matters for safety and warranty
- How Workily makes booking a boiler service simple
- What actually matters most in a boiler service
- Book your next boiler service through Workily
- Sources
What does a boiler service actually include?
A proper boiler service is a lot more than a quick glance and a sticker on the casing. Done correctly, it follows a defined technical sequence that any competent engineer should walk you through, not rush past.
The engineer starts with a visual inspection: the flue, the outer casing, the seals and pipework, checking for corrosion, staining or damage that hints at a leak. From there they move into the mechanics, cleaning the burner and inspecting the heat exchanger for any build-up or scaling.
The most important technical step is combustion, or flue gas, analysis. The engineer inserts a probe into the flue and measures carbon monoxide (CO), carbon dioxide (CO2), and the ratio between them, alongside a gas-rate check to confirm the boiler is burning fuel correctly. This full checklist of a proper annual service also covers testing safety devices and controls, checking system pressure, and inspecting the condensate trap for blockages.
Pro Tip: Ask to see the combustion analyser reading before the engineer packs up. A number written on the service report, not just a verbal “it’s fine”, is the clearest proof a full service actually happened.
If the CO reading or CO/CO2 ratio comes back outside accepted safety limits, a properly trained engineer will investigate the fault rather than sign off the appliance as safe. That single check is what the whole visit is really for.
Everything gets recorded on a completed Benchmark or service report, which should include:
- Combustion readings (CO, CO2, and the CO/CO2 ratio)
- Confirmation the burner and heat exchanger were checked and cleaned
- Results of safety device and control tests
- System pressure and condensate trap notes
- The engineer’s name, registration number, and the date of the next service
Who is legally allowed to service a gas boiler?
Only a Registered Gas Installer (RGI) may legally carry out work on a gas boiler in Ireland. This isn’t a quality preference, it’s a safety requirement rooted in the risks of carbon monoxide and gas leaks, and it’s the reason the register exists in the first place.
Before anyone touches your boiler, run through this quick verification:
- Ask for the engineer’s RGI number and check it against the official RGI register before the appointment, not after.
- Check the photo ID card they carry matches the name and registration you were given.
- Confirm the registration covers the specific work you need, since some RGIs are certified for particular appliance types only.
- If they can’t produce ID or a valid registration number, stop the job immediately.
If someone turns up unregistered or refuses to show ID, don’t let them near the appliance. You can report the concern through the RGI website. It’s a five-minute check that could save you from a badly executed job or, far worse, a genuine gas safety hazard.
How much does a boiler service cost in Dublin?
Prices vary more than most homeowners expect, and the gap usually comes down to who you book rather than what gets checked. An independent RGI engineer booked directly will typically sit at the lower end of the fair-market range, while a national supplier’s branded service plan often carries a noticeable premium for the same core checklist.
A few factors push the price up or down:
- Season: booking in spring or summer, when demand is lower, tends to cost less than scrambling for an engineer in the depths of a cold January.
- Timing: emergency or out-of-hours call-outs always cost more than a scheduled daytime appointment.
- Boiler type: older systems, back boilers, or unusual installations can take longer and cost more than a standard modern combi.
- Discovered faults: if the engineer finds a worn part during the service, replacing it adds to the bill, so ask for a separate itemised cost before agreeing.
On cover plans: an annual maintenance plan can make sense if your boiler is old or prone to faults, since it bundles in priority call-outs. But if your system is relatively new and reliable, independent engineers booked off-peak often work out cheaper than paying into a bundled cover plan year after year. Do the maths on what you’d actually claim before committing.
Servicing costs also tie into your wider running costs, since a poorly maintained boiler burns more gas for the same heat output. If efficiency is on your mind beyond the annual check, it’s worth reading about home energy efficiency improvements that compound the savings.
How long does a boiler service take?
A healthy, modern combi boiler usually takes an engineer 30 to 45 minutes to service properly. Older systems, back boilers, or units with a history of faults can take up to 90 minutes, since there’s simply more to inspect and clean.
Watch for the warning signs of a rushed job: a visit lasting 15 minutes or less, no combustion analyser ever coming out of the toolbox, or the engineer leaving without handing over any paperwork. A genuine service leaves physical evidence, casing panels removed and refitted, a probe used in the flue, and a completed report in your hand before they leave.
What should you ask before and during the visit?
When you call or message an engineer, ask about their RGI registration number, whether combustion analysis is included in the quoted price, and what the cancellation policy is if you need to reschedule.
On the day itself, run through this checklist:
- Check the engineer’s photo ID against the RGI number they gave you at booking.
- Ask them to show you the combustion analyser reading once the test is complete.
- Insist on a signed service report or Benchmark document before they leave, not “we’ll email it later”.
- If they propose a repair, get an itemised quote covering parts and labour separately.
- Ask whether original manufacturer parts will be used, since generic substitutes can affect your warranty.
Pro Tip: Keep the questions short and specific. An RGI engineer with nothing to hide will answer all five points without hesitation, usually before you’ve finished asking.
For a step-by-step walkthrough of the whole process from quote to completed job, this guide on how to service a boiler in Ireland covers the practical booking pathway in more detail, and Mystic Valley Services’ homeowner guide is a useful second opinion on what the visit should look like.
Why the service report matters for safety and warranty
The paperwork you get at the end of the visit isn’t a formality, it’s your evidence. Manufacturers commonly require an annual service record to validate a warranty claim, and without it a claim can be refused outright, even if the fault is clearly a manufacturing defect.
Keep a copy, photographed or scanned, somewhere you’ll actually find it again. On the report itself, check for:
- The engineer’s name and RGI registration number
- The full set of combustion readings, not just a pass/fail tick
- A plain explanation of any repairs carried out
- The recommended date for the next service
Landlords have a separate, stricter obligation. A homeowner’s annual service report is not the same as the CP12-style gas safety certificate landlords must issue under Irish rental regulations, so if you’re renting out a property, check what documentation your obligations specifically require. Retaining that service record is the one habit that protects you most cheaply, long after the engineer has left.
How Workily makes booking a boiler service simple
Booking through Workily means you can search for RGI-checked engineers and confirm availability without the usual round of phone tag. You specify what you need, a full service, combustion analysis included, and get matched with verified professionals who can often turn up the same day.
Workily reports a 98% satisfaction rate across more than 100,000 customers, which reflects a vetting process that checks registration before a professional ever appears in search results. That doesn’t remove your job as homeowner, though. Once the engineer arrives, still ask for the combustion analyser reading and insist on a signed report. Photograph it and store it somewhere safe, alongside any previous years’ records, so warranty claims or future sales have a clean paper trail. Our guide on boiler servicing for homeowners walks through what to check at each stage.
What actually matters most in a boiler service
Most advice on this topic obsesses over price comparison and skips the one thing that actually determines whether you’re safe: the combustion reading. A cheap service with no analyser used is worse than a slightly pricier one that produces a proper CO/CO2 figure on paper, because the entire point of an annual check is catching a slow carbon monoxide leak before it becomes dangerous.
Conventional advice tends to frame servicing as a box-ticking chore, something you do because the manual says so. That undersells it. The real value isn’t the tick on a maintenance schedule, it’s the twenty minutes an RGI engineer spends with a probe in your flue, looking for a number that shouldn’t be there.
If you take one thing from this guide, prioritise verification over price. Check the RGI number before the engineer arrives, not after. Ask for the reading. Keep the report. Everything else, the euro amount on the invoice, the time of year you book, the brand of the boiler, matters far less than those three habits, and they cost nothing extra to insist on.
— Thomas
Book your next boiler service through Workily
Workily is the practical alternative to ringing round for quotes and hoping someone calls back. In and around Dublin, a booking feature lets you compare registered engineers side by side and request a combustion analysis and signed service report as part of the job, rather than as an afterthought you have to chase.
Get quotes from more than one engineer before you commit, since prices for the same checklist can vary by season and supplier type. Once the work is done, keep the service report on file for warranty purposes and note the date your next service falls due. Head to Instant Booking to compare verified boiler engineers near you and get a service booked in for a time that suits your household.
Sources
- Service your Boiler – Registered Gas Installers (RGI)
- Annual boiler service checklist
- Boiler service: real costs and what’s checked (Selectra)
