Home /Top Questions to Ask Before Booking a Gas Boiler Service
When planning to install a new boiler or looking for a replacement, it is important to ask the right question to your gas boiler expert. This can help save money, time, and keep you off future headache or trouble.
In the UK, about 1 in 6 gas appliances are actually unsafe, according to the Gas Safe Register. That is a terrifying stat when you think about it. We are talking about carbon monoxide risks, which unfortunately still cause around 30 accidental deaths and 200 hospitalisations every year in England and Wales. So, when you call out one of the local boiler repair companies, you aren’t just paying for a sticker; you are paying for peace of mind. Let’s walk through the big questions you should be asking your boiler engineer.
If your engineer suggests a gas boiler replacement during the service, you need to know which type of boiler fits your lifestyle. It is not a one-size-fits-all situation.
Most of us just call these “Combis.” They are great for smaller homes because they heat water directly from the mains. No big tank in the loft, no waiting for a cylinder to heat up. It is instant, but if two people try to shower at once, someone is going to get a cold shock.
Also known as regular or conventional boilers. These are the old-school ones that need a cold water tank and a hot water cylinder. If you have a massive house with older pipework, this might be your best bet because it doesn’t put as much pressure on your radiators.
These are like the middle ground. They need a cylinder for hot water but most of the “guts” are built into the boiler itself. They are brilliant for big families who need lots of hot water at once without cluttering the loft with extra tanks.
This is the big one. You don’t want to spend £2,000 if a £100 service can fix it. However, a poorly maintained boiler can lose 10% to 15% efficiency, which is basically like burning money. If your boiler is over 10 or 15 years old, the parts become harder to find and it might be safer to swap it out. An efficient new model can save you between £100 and £300 a year on your energy bills, so sometimes the investment pays for itself fairly quickly.
Always ask about the “paperwork.” Most UK manufacturers require proof of an annual gas boiler service to keep your warranty valid. If you skip a year, that 10-year guarantee you were promised is basically worth nothing. Make sure your boiler engineer is Gas Safe registered—it is the law in the UK—and ask if they are accredited by specific brands like Worcester Bosch or Vaillant, as that often gets you an extra few years of cover for free.
Always ask about the “paperwork.” Most UK manufacturers require proof of an annual gas boiler service to keep your warranty valid. If you skip a year, that 10-year guarantee you were promised is basically worth nothing. Make sure your boiler engineer is Gas Safe registered—it is the law in the UK—and ask if they are accredited by specific brands like Worcester Bosch or Vaillant, as that often gets you an extra few years of cover for free.
A service is the perfect time to ask how to lower those eye-watering bills.
You don’t need your hot water to be scalding. Lowering the flow temperature on a combi boiler can save a decent chunk on your monthly spend without you even noticing the difference in the shower.
Some newer setups can have an economiser or “Flue Gas Heat Recovery” system. It captures the heat that usually goes out the pipe and uses it to pre-heat your water. It is a bit like recycling heat.
Don’t just wait for it to go “bang.” Regular servicing (which usually costs between £70 and £120 in the UK) keeps the internal parts clean and prevents that 15% efficiency drop I mentioned earlier. This is why picking reliable boiler repair companies for annual check-ups is so vital.
It sounds simple, but heat escapes from every exposed bit of metal. Cheap foam jackets for your valves and pipes keep the heat in the water and out of your cupboards.
You don’t want your house to be a building site for a week. A straightforward “like-for-like” swap (combi for a combi) usually takes about a day. However, if you are moving the boiler from the kitchen to the loft or switching from a tank system to a combi, you are looking at two to three days of work.
Read More: Boiler Installation Checklist
At the end of the day, your boiler is the heart of your home. It keeps you warm and ensures your morning shower isn’t a miserable experience. While nobody likes spending £70 to £120 on a gas boiler service, it is a lot cheaper than an emergency call-out or, heaven forbid, a hospital visit. Be proactive, ask your boiler engineer the tough questions, and make sure they are legal and registered. It keeps your house warm, your bills lower, and your family safe.
You should always ask to see their ID card. On the back, it will list exactly what they are qualified to work on. You can also pop their licence number into the official Gas Safe Register website to be 100% sure.
Beyond the safety aspect of checking for carbon monoxide, it is about the warranty.
Manufacturers are quite strict; if you don’t have a service record for every year, they won’t pay out for repairs if the heat exchanger or pump fails.
Not quite. A safety check ensures the appliance is safe to run, but a service is a deeper “clean and tune-up.” Think of it like an MOT versus a full car service. You want the service to ensure it actually runs efficiently.
That is often called “kettling.” It usually means there is a buildup of limescale or sludge in the system. A service can identify this, and the engineer might suggest a “power flush” to clear the gunk out and get things quiet again.
Honestly, do it in the summer. Engineers are way less busy, and if they find a part that needs replacing, you won’t be freezing while you wait for it to arrive. Plus, you’ll be all set for the first cold snap in October.
