Boilers FAQ

Yes, if your home is reasonably insulated and you want lower-carbon heating long term. Air source heat pumps use roughly a third of the input energy of a gas boiler for the same heat, and can qualify for up to £7,500 off through the Boiler Upgrade Scheme when eligible. A new gas boiler still suits homes where gas is in place, insulation is limited, or upfront cost is the priority. We install both and can compare for your home.

We install across England, Scotland, and Wales on UK mainland. When you request a quote we confirm coverage for your postcode and typical lead times, usually in the 3-5 day range for boilers. We don't cover Northern Ireland, the Channel Islands, or the Isle of Man.

No, not for a like-for-like gas-to-gas swap. The Boiler Upgrade Scheme only funds heat pump replacements. If you are on a low income or qualifying benefits, the ECO4 scheme and the upcoming Warm Homes Plan can cover boiler-related upgrades. Our 2026 grants guide walks through every option.

Yes, in most cases. A modern condensing boiler runs at around 90% efficiency, compared with 60-70% on older non-condensing units. The bill saving depends on your existing boiler's age and condition, your insulation, and how you use heating. Older G-rated units replaced with an A-rated condensing model typically deliver the biggest reduction. See our new boiler guide.

Yes, prices have moved upward in recent years. Two drivers stand out: rising wholesale gas and component costs, and the Clean Heat Market Mechanism, which requires manufacturers to sell a quota of heat pumps (8% in Year 2) or pay a per-unit penalty. That cost tends to filter into boiler list prices, so replacing now locks in current pricing. Browse the boilers hub for options.

For most boiler replacements, yes. Modern condensing boilers have narrower heat exchangers and are more sensitive to sludge and debris from older pipework. A full power flush protects the new boiler, helps maintain efficiency, and is usually required by the manufacturer to validate the warranty. Every UKEM boiler installation includes a power flush as standard.

Usually yes. Most radiators work with a new gas boiler as long as they are in sound condition and properly sized for each room. Our engineer carries out a heat-loss check on install day to confirm the radiator output matches the heat demand. If a radiator is undersized or corroded we will flag it before work starts so there are no surprises.

Often, yes. Many of the boilers we install include or recommend a smart thermostat, and we fit one as part of the upgrade where it makes sense. A good one can save around 10-15% on heating bills through better scheduling, geofencing, and room-by-room control. Your quote shows whether a thermostat is included or available as an add-on.

Quick rule of thumb: combi for 1-2 bathroom homes with decent mains pressure (no tank, hot water on demand). System for 2-3 bathrooms or homes that need stored hot water but want a sealed setup. Regular (heat-only) for larger homes, low mains pressure, or where the existing cylinder and tank layout stays. See our full comparison guide.

Yes, this is legally required in the UK. Anyone working on gas appliances in your home must be on the Gas Safe Register. Unregistered work is illegal, unsafe, and invalidates your boiler warranty and home insurance. Every UKEM engineer is Gas Safe registered, and we provide the Building Regulations notification after every install.

For most homes, no. The rollout of hydrogen home heating in the UK is uncertain and unlikely to reach most households this decade. Modern condensing boilers are already partially compatible with hydrogen blends up to 20% in the gas grid, so you are not locked out by replacing now. If hydrogen heating arrives, the conversion path is straightforward. See the heat pumps page for a lower-carbon alternative available today.

A modern gas boiler typically lasts 10-15 years with annual servicing. Lifespan depends on water quality, system cleanliness, usage patterns, and how well it was installed. Annual servicing protects the manufacturer warranty and catches small faults before they become breakdowns. Once a boiler is past 12 years and starting to fail, replacement is usually more cost-effective than ongoing repairs.

Once your quote is agreed, you apply for finance online with our FCA-authorised lender. You choose a term that fits your budget and pay a fixed amount each month by direct debit. The full installation cost is settled with us by the lender, so your engineer fits the boiler as normal. See our finance page for the full process and eligibility.

No for a quote alone; yes if you apply for finance. Getting an installation price doesn't touch your credit file. A full finance application runs a credit check recorded on your file, and only happens once you choose regulated credit. See our finance page for full detail.

No, not usually. Some plans are zero-deposit and others ask for an upfront contribution, which can lower the monthly payment or amount borrowed. The lender confirms what's available when you apply. You can put down more than the minimum if you prefer. Visit our finance page for current options.

Yes. Under FCA-regulated consumer credit, you have the right to settle your agreement early at any time. On 0% interest-free plans there is nothing extra to pay, you simply clear the remaining balance. On interest-bearing plans you receive an interest rebate for the unused term, so you only pay interest for the time you held the finance. Ask the lender for a settlement figure when you are ready.

UKEM Group is an Appointed Representative of Shermin Finance Limited, which is authorised and regulated by the FCA and acts as a credit broker, not a lender. Finance agreements are provided by an FCA-authorised lender. You receive the full pre-contract information, APR, total payable, and your right to withdraw before you sign. Credit is subject to status and affordability. The finance page sets out the lender details and our disclosure in full.

Usually, yes. A 20-year-old boiler typically runs at 70-80% efficiency against 90%+ for a modern A-rated unit, so roughly a fifth of your gas spend is wasted heat. Spare parts get scarce at that age and breakdown risk climbs. If it's safe and serviced it can keep running, but replacement usually pays for itself in lower bills and avoided repair costs.

Worcester Bosch, Vaillant and Ideal consistently top UK reliability and installer surveys. UKEM installs Worcester Bosch (4000 and 8000 series) and Ideal (Logic and Vogue) because their build quality, parts availability and warranty support hold up across thousands of installs. The right brand matters less than the right model and size for your home, which is what the online quote works out.