How often should a gas boiler be replaced?

30 August 2023

How often should a gas boiler be replaced?

Gas boilers are complex but tough pieces of machinery that have been improved greatly over the years. But because you completely rely on for your hot water and to keep you and your family warm in the winter, you want to keep yours running as reliably as possible.

Many people ask us how long they can expect their boiler to last once it has been installed. There are two answers to this question, really. There’s the amount of time it’ll last if it is regularly maintained and serviced, and how long it would last if it was completely neglected.

A well serviced boiler

When you have your boiler installed, it will come with a warranty that protects you from unexpected repair bills for quite a long time. In general, these warranties last between 7 and 10 years, although sometimes they can be as long as 12 years.

However, that warranty does come with a very important condition – you must have it serviced by a professional boiler engineer at least once every 12 months, starting the day it’s installed. The engineer will probably stamp the log book or give you a receipt of some kind whenever they do a service, and that will be your proof that you have kept your side of the deal.

Servicing is very important from a safety and an efficiency point of view. The process tests for carbon monoxide, ventilation, pressure and all the things that keep the machine safe and cheap to run. If it uncovers any issues, you can have them repaired or have components replaced. Since faults in gas boilers tend to get worse over time (limescale build-up being a typical problem), finding and repairing it early is very important.

If you miss a service, however, the boiler manufacturer may consider your warranty voided, and you will have to foot the bill for any repairs. There could also be certain repairs that are excluded from free repairs. For example, themistors or external casings might not be covered. Different manufacturers have different stipulations, so check the small print and look at comparison sites for good deals.

So, judging by the manufacturer’s confidence in their products, it’s fair to assume you can get about 10 or 12 years’ service out of your boiler as long as you’ve kept it well maintained.

In reality, that kind of duration is when you can expect your boiler to be running at its most efficient, and is based on average wear and tear. If you use your boiler quite lightly, and live in a soft water area, you could probably get upwards of 15 years’ use out of it. If you have your boiler running almost 24/7, for example in a house with multiple occupants demanding hot water and heating, the 10 year mark could be a little more realistic.

As mentioned above, boilers run at good efficiency over that first decade of use. But that’s not to say they will completely stop working after then. You’ll probably have a few years where it’s not running at peak performance, with water not quite reaching the same temperatures as it used to, or you may notice your gas bills being higher than they were. You could find that after 10 years, components might start to fail, and they will need fixing or replacing. In other words, there’s still life left in the old thing, but it’s up to you whether you think you should replace it based on running costs and quality of life, but it’s fundamentally safe.

Basically, though, you should be good for 10 years or however long the warranty lasts, and if anything does fail during that time, it should be repairable.

An unserviced boiler

If, on the other hand, you have a boiler installed and then fail to look after it, its lifespan will almost certainly be greatly reduced.

As we said at the start, they are pretty robust pieces of kit, designed to undergo high temperatures, frequent hot and cold cycles and flowing fluids, and have moving parts like pumps and valves that are regularly running to keep your boiler pumping out heat. But nothing is indestructible, so there will always be small repairs to do.

Just as your car will need new tyres and brake pads every so often, so boilers need new components as they wear out. If you ignore your tyres or brake pads, they could fail catastrophically and damage your wheels, bodywork, axle or engine – or even endanger your life. In other words, failing to maintain your boiler will probably mean that your engineer doesn’t get the chance to diagnose something small, which means something bigger happens down the line.

For that reason, it’s not really wise to guess what the lifespan of an unserviced boiler would be, as there could be as little as a year or two before something big fails and your repair or replacement bill would be many times the cost of a service and routine repair.

In short – make sure you always have your annual service. It’s about an hour out of your life every twelve months, but it can pay for itself many times over.

Signs that say you need a new boiler

If you want to get as many years as possible out of your boiler, an annual service will surely help, but inevitably, things will start to wear out eventually. You don’t want to take any chances, so here are a few things to look out for that could signal it’s time for a new one.

  • Strange sounds – boilers aren’t supposed to be completely silent, but if you notice unusual sounds coming from it, it’s likely that there’s an issue. Find out more about boiler noises here.
  • Leaks – If you find puddles around the boiler, or indeed if you see or hear drips coming from it, it’s definitely worth calling the professionals. Find out more about boiler leaks here.
  • Carbon monoxide alarms – It’s absolutely vital that you get it checked out if your CO alarms are going off. Keep your home ventilated and call your boiler engineer today.
  • Regular breakdowns – All machinery breaks down from time to time, but if your boiler is regularly needing repairs, it probably makes financial sense to invest in a new one.

Whether you need a boiler service, repair, replacement or just to check something you’re worried about, please get in touch so we can give you a quote.