Top 10 Things to Consider When Replacing Your Boiler
Replacing your boiler isn’t something most of us do often – and when the time comes, it can feel like a bit of a minefield. With over 25 years of experience fitting thousands of boilers across North London and Hertfordshire, we know exactly what questions homeowners ask – and what they should be asking.
Whether your boiler’s on its last legs, your heating bills are creeping up, or you just want to futureproof your home, here are the top 10 things to consider when replacing your boiler.
1. Age of Your Current Boiler
If your boiler is over 10–15 years old, chances are it’s no longer operating efficiently – and replacement is worth considering. Even if it’s still working, you could be wasting energy (and money) every time you turn the heating on. Most modern boilers are over 90% efficient – compared to 60–70% for older models.
2. Type of Boiler: Combi, System or Conventional?
Not all boilers are created equal. The three main types are:
Combi boilers (most common): Heat water on demand, no storage tank needed.
System boilers: Use a cylinder to store hot water – good for larger households.
Conventional boilers: Require both a cylinder and a tank – usually found in older systems.
The right choice depends on your home, lifestyle, and space.
3. Your Home’s Heating and Hot Water Demand
Do you live alone in a flat, or have a busy household with two bathrooms and teens who love long showers? Your heating and hot water usage should inform the size and type of boiler you choose. An oversized boiler is inefficient; an undersized one won’t cope.
4. Boiler Efficiency and Energy Bills
Swapping an old boiler for an A-rated model can significantly reduce your energy bills. Many homeowners see savings of £200–£400 per year depending on the efficiency of the old system. Look for efficiency ratings, and ask your installer to help you estimate potential savings.
5. Installation Costs – And the Hidden Ones
The boiler itself is only part of the cost. You’ll also need to budget for:
Pipework adjustments (if needed)
Flue replacement
Controls and thermostats
Removal of your old boiler
A reputable installer will give you a clear, all-in quote with no surprises.
6. Where Will the New Boiler Go?
In many cases, the new boiler can go exactly where the old one was. But if you’re switching boiler types (e.g. from a system to a combi), relocation might be necessary. We always consider ventilation, accessibility, and compliance with current regulations when advising on placement.
7. Smart Controls and Thermostats
Upgrading your boiler is the perfect time to install smart heating controls. You’ll have better control over your heating, save energy, and manage everything from your phone. Some systems even learn your habits to keep you warm without wasting energy.
8. Futureproofing: Hydrogen-Ready or Hybrid Systems
Many modern boilers are now “hydrogen-ready” – designed to work with future low-carbon fuels. If you’re not ready for a full heat pump system, choosing a hydrogen-ready boiler or a hybrid system (combining gas and electric) helps futureproof your home as we head toward net zero.
9. Warranties, Guarantees and Peace of Mind
A good boiler should last 10–15 years – and the best models come with warranties of up to 10 years. Make sure your installer is accredited by the manufacturer so you can access full warranty protection. At Calidra, we always register your warranty and make sure you know how to keep it valid (e.g. with annual servicing).
10. Your Installer: Reputation Matters
This is arguably the most important factor. A boiler is only as good as the engineer who fits it. Choose a Gas Safe registered installer with great local reviews, clear pricing, and experience working in your type of property. Don’t be afraid to ask questions.
Final Thoughts
Replacing your boiler is an investment in your home – not just for comfort and reliability, but for energy efficiency and long-term savings. Whether you’re upgrading to a more efficient model, switching to a different boiler type, or thinking about your home’s carbon footprint, getting the right advice and the right installer is key.
At Calidra, we specialise in helping homeowners make the best decision for their home. No jargon, no upselling – just straight-up advice and expert installation.
