Boiler Servicing in Paisley & Renfrewshire
A proper annual service, with the combustion figures written down and handed to you at the end. Not a five-minute look and a sticker.
The case comes off. Every time.
There is a version of a boiler service where someone turns the heating on, watches it fire, fills in a card and leaves. It takes ten minutes and it tells you nothing.
A real service means the case comes off, the burner comes out, and the boiler is tested under load with a calibrated flue gas analyser. That is the only way to know whether it is burning cleanly or slowly drifting out of tolerance — and drift is invisible until the day it locks out.
On a modern condensing boiler I am looking for a CO to CO2 ratio comfortably under 0.004, a gas rate at the meter that matches the data plate, and case seals that are still doing their job. A room-sealed appliance relies on those seals. Perished ones are one of the most common things I find and one of the cheapest to put right.
What I check, and why
Flue route and terminal
Where the flue runs, whether it is still sealed where it passes through the wall, and whether anything has been built or boxed around it since. Flues in ceiling voids need an inspection hatch — a lot of older installs here do not have one.
Case off, burner out
Burner, injectors and electrodes cleaned or replaced. Heat exchanger fins checked for debris and corrosion. The condensate trap gets emptied and refilled.
Combustion analysis under load
Analyser in the test point, boiler running at maximum rate. I write the readings down and you get a copy. If they are outside manufacturer tolerance the boiler needs work, and I will say so.
Gas rate at the meter
Timed against the meter and compared with the data plate. An under-gassed boiler will never make its output and will nuisance-lock in cold weather.
Safety devices and pressures
Standing and working pressure with a manometer, flame supervision, overheat stat, pressure relief valve and expansion vessel charge. A flat vessel is behind most of the pressure-loss calls I get.
Re-seal, re-test, write it up
Case sealed properly, boiler re-tested, and the service recorded in the benchmark book so your warranty stays intact.
What it costs and how long it takes
| Typical time on site | 45 minutes to an hour on a boiler that has been serviced regularly. Longer if it has been left several years — expect more cleaning and possibly parts. |
|---|---|
| What you get | Written combustion readings, benchmark book completed, and a straight answer on anything that needs attention. |
Renting the property out?
A service and a landlord gas safety certificate are two different jobs, and the certificate does not include a service. Most landlords I work for have both done on the same visit — it is one appointment for the tenant and it keeps the boiler warranty valid.
Questions I get asked
Does a service keep my warranty valid?
On almost every manufacturer, yes — and they will ask for proof. The service has to be annual, done by a Gas Safe registered engineer, and recorded in the benchmark book at the back of the boiler manual. A missing year is the usual reason a warranty claim gets turned down.
The boiler is working fine. Do I still need it done?
Combustion drifts gradually and case seals perish slowly, so a boiler can be running badly for a long time before you notice anything. The service is what catches it while it is still a cheap fix. It is also the only way anyone can confirm it is not producing carbon monoxide.
What happens if you find something unsafe?
I classify it under the Gas Industry Unsafe Situations Procedure — either Immediately Dangerous or At Risk — explain what that means in plain terms, and ask for your permission to make it safe. Nothing gets disconnected without your say-so unless it is genuinely dangerous to leave.
How often should a filter be cleaned?
Every service. If you have a magnetic filter fitted I empty and flush it as part of the visit, and how much comes out of it tells me a lot about the state of the system water.
Book this year's boiler service
Most services take under an hour. I will give you the combustion figures at the end and tell you what to watch.