If you have had a boiler service recently and you are still wondering whether it was done properly, you are not being fussy. A boiler service is a safety check and a performance check, so it should leave you with clear evidence of what was tested, what was cleaned, and what condition the boiler was left in. The good news is you can verify a lot of this without tools, without removing covers, and without being a heating expert.
8 Signs Your Boiler Service Was Completed Properly
Check the service record first, not the boiler
The easiest way to confirm the service was completed correctly is the documentation left behind. You should have a dated service record that includes who carried out the work and what was done. Many boilers also have a Benchmark logbook within the manual pack, and this is commonly updated at each service.
A proper record is specific, not vague. It should not just say “serviced” with no detail, because a service is made up of individual checks. If you only received an invoice, ask for the service checklist or written notes that match what was inspected.
Look for proof of safety checks, not just “it’s working”
A boiler can turn on and still be unsafe or inefficient, so “it fires up” is not proof of a correct service. A proper service involves safety-focused checks, particularly around the flue, combustion, and signs of overheating or leakage. The service notes should reflect that these areas were checked and found satisfactory, or that issues were raised.
If the paperwork mentions flue checks, ventilation, and combustion-related readings, that is usually a strong sign the service was done properly. If nothing safety-related is mentioned at all, ask what checks were completed and whether any readings were taken during the visit.
Confirm the flu was inspected properly
The flu is one of the most important safety areas, so it should not be ignored. You can do a basic visual check by looking at the visible flue sections where accessible, without touching anything. You are looking for secure joints, no obvious gaps, and no signs of staining or heat marks around the flue area.
You should also check that nothing has been stored against the flue or blocking airflow around the boiler. If the engineer moved items to access the boiler, a good service normally ends with the area left clear and safe.
Check for signs the casing was removed and refitted correctly
On many boiler services, the engineer needs to remove the front case to access internal components, so after the visit the casing should sit flush and secure. Screws should be present and tight, and there should not be loose panels or rattles when the boiler runs. A missing screw or poorly refitted cover can indicate rushed work or a simple oversight.
You should also notice that the boiler and surrounding area are left tidy. A correct service might involve a small amount of water discharge during checks, but it should not leave drips, stains, or wet patches.
Pressure behaviour can reveal a lot in the days after
For combi boilers and sealed systems, the system pressure is one of the easiest things to monitor after a service. Check the pressure gauge and note the reading when the system is cold, then check again after the heating has been on for a while. You are not trying to hit an exact number, you are looking for stable behaviour.
If pressure drops noticeably over a day or two, it may point to a small leak or an issue with the expansion vessel. If pressure rises sharply when heating is on, that can also indicate system faults. These issues are not always caused by the service, but a correct service should notice warning signs and mention them.
Listen to how the boiler runs after the service
A boiler that has been serviced correctly should run smoothly and consistently. Some noises can be normal, but sudden changes right after a service are worth noting. Pay attention to frequent cycling on and off, repeated ignition attempts, loud banging, or persistent gurgling.
If you notice anything new, report it quickly. The sooner you feed back, the easier it is for the engineer to diagnose whether it is linked to an adjustment, a part that is wearing out, or a system issue that needs attention.
Ask the right questions if you are unsure
If you want to confirm the service was done correctly, ask practical questions that link directly to the work a service should include. Ask what was checked, what was cleaned, and whether anything was noted as borderline. You can also ask whether any parts showed wear that might need monitoring over the next year.
You should not feel awkward doing this. You are not challenging the engineer, you are verifying that you received the full service you paid for and that your home is safe.
What a good outcome looks like
When a boiler service has been done properly, you should have a clear record of the work, confidence that safety checks were completed, and a boiler that behaves normally afterwards. You should also know whether there are any recommended improvements, even if they are not urgent, because good servicing is as much about preventing problems as it is about checking today’s performance.
If anything feels unclear, you are within your rights to request the service details in writing. A professional company will usually be happy to explain what they did and what it means for your boiler.
Book A Boiler Service Check In Rossendale, Burnley, Rochdale And Ramsbottom
Want a second opinion on whether your boiler service was completed properly? JS Gas & Oil Ltd can review what was done and carry out a service check, so you know your boiler is safe and running as it should. Call 07791 802791 or fill out our contact form to book in today.
