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A new boiler is one of those purchases no one plans for it. It always happens at the worst time when the heating stops working on the coldest day of the year.
And then comes the stressful part: calling around, getting quotes, and wondering how much is a new combi boiler with installation actually costs.
The final cost depends on the boiler size, brand, and the work required for your property. Every home is different, so the best way to know is to get a professional survey and a quote for your home.
In this guide, we’ll break down how much is combi boiler installation, what affects the cost, what’s included in a proper installation, and how you can make sure you’re getting a fair price – with no confusing jargon and no hidden extras.
What’s Included In A New Combi Boiler With Installation
A full quote from a Gas Safe engineer should cover everything needed to fit the boiler safely and legally.
The combi boiler unit – The price varies by brand and kW output
Installation labour – Removal of the old boiler, fitting the new one, testing, and Gas Safe certification team.
Essential parts – Flue, magnetic filter, controls, and any pipework required
Some companies advertise a low price for “boiler only” or a basic swap. Always make sure your quote lists all parts and labour so there is no extra charge.
Factors That Affect Combi Boiler Installation Cost
If you’re wondering how much for combi boiler installation, it’s to understand that the final price depends on these key factors
1. Boiler Size and Brand
The combi boiler installation cost depends on the KW output needed for your home and the manufacturer. Smaller flats need a lower kW boiler, while larger homes need a higher output. Premium brands often come with longer warranties.
2. Installation Type
A replacement in the same location is usually the most straightforward. Costs increase if the boiler is being moved to a new location, as this requires new pipework and flue work.
3. Additional Work Required
- Power flush: Cleans the system so the new boiler runs efficiently
- Magnetic filter: Required by most manufacturers to protect the warranty
- Smart thermostat/controls
- New flue
- Gas pipe upgrade
If your current system has sludge or the gas pipe is too small, additional work may be needed to meet regulation.
Combi Boiler And Radiator Installation Cost
If you are going to replace the older boiler and radiators at the same time, the Combi Boiler And Radiator Installation Cost will be higher than a boiler-only installation.
The total cost is included with the new combi boiler installation cost, all radiators, valves, pipework, and system cleaning. Replacing individual radiators will also add to the total cost.
Cost Of Combi Boiler And Installation By Property Size
1-2 Bedroom Flat / Small House
Usually requires a lower kW combi boiler. 3-Bedroom Semi-Detached House Typically requires a mid-range kW boiler and may need a system clean and filter.
4-5 Bedroom Detached House
Usually requires a higher kW boiler and may need additional controls or gas pipe upgrades. Prices can also vary by region across the UK.
How To Keep Costs Down
1. Get Multiple Quotes
Always compare quotes that list the exact boiler model and what is included.
2. Book At The Right Time
Installers may have better availability outside of the winter months.
3. Check Warranty Requirements
Most manufacturers require a magnetic filter and system clean for the warranty to be valid. This protects your investment long term.
What Is Not Usually Included
Some quotes do not include:
- Building or decorating work after installation
- Additional smart controls
- Annual servicing
Before any work starts, make sure you get everything in writing.
A proper written quote should list the exact boiler model, what’s included in this, how long the job will take, and the total price, including VAT. No guesswork, no surprises, no costs later.
It also protects you. If it’s written down, both you and the installer know exactly what’s being done.
Is A Combi Boiler Worth The Investment
Combi boilers heat water on demand, so there’s no big tanking up space in your airing cupboard. A new A-rated combi boiler is much more efficient than an older 15-year model – which means lower bills month after month.
Think of it like this: you’re not just paying for a boiler today. You’re investing in comfort, reliability, and peace of mind for the next 12 to 15 years.
With proper servicing of your boiler, a new combi boiler should last many years, helping to reduce energy bills.
Choosing The Right Installer
For safety and warranty purposes, your installer must be Gas Safe registered.
Look for:
1. Gas Safe registration
This is a legal requirement. Only a Gas Safe registered engineer can install your boiler safely and sign off the work.
2. Manufacturer accreditation for longer warranties
Accredited installers can offer longer manufacturer warranties. That means better protection for your new boiler.
3. Clear written quote with the boiler model
Your quote should list the exact boiler models, all parts, and labour. No vague pricing or hidden extra
4. Customer reviews
Check what other homeowners are saying. Good reviews are the best sign of reliable work and aftercare.
The cheapest quote isn’t always the best value. Pick an installer who explains the work clearly and provides proper certification with you
Conclusion
A new combi boiler is a big decision, but it doesn’t have to be stressful.
At the end of the day, it comes down to 3 things: the right boiler for your home, a safe, professional installation, and a clear quote with no surprise.
The best way to know the exact new combi boiler installation cost for your property is to book a survey. Unique Gas and Heating Solutions has a reliable team. Book a survey with our Gas Safe engineer who will check your current system, explain your options, give you a fixed price before any work starts, recommend the right boiler, and ensure boiler installation is done right the first time.
For an accurate price, book a home survey with Unique Gas and Heating Solutions. A professional installer will check your current system and provide a fixed quote with no hidden costs.
Don’t wait for your old boiler to break down in the middle of winter. Get the free quote today and get a peace of mind for years to come.
Frequently Asked Question (FAQs)?
1.How long does it take to install a new combi boiler?
For a straightforward like-for–like swap it usually takes 1-2 days. If the boiler is being moved to a new location or extra work like a power flush is needed, it can take longer. Your installer will confirm this during the survey.
2. Do I need a power flush with my new boiler?
Not always. But if your current system has sludge or debris, a power flush is recommended. Most manufactures also require a system clean and magnetic filter to keep your warranty valid.
3. What size combi boiler do I need for my home?
It depends on how many bathrooms, and your hot water demand. A smaller flat usually needs a lower kW boiler, while a larger house with 2+ bathrooms needs a higher kW model. A Gas safe engineer will size it correctly for you.
4. Is my installer required to be Gas Safe registered?
A Gas Safe registered engineer can legally install and certify a gas boiler. Always check their ID card before work start.
5. What’s the difference between a budget and a premium boiler brand?
The main differences are warranty length, reliability, and aftercare. Premium brands often come with 10-12-year warranties. Budget brands may have shorter warranties. Your installer can explain which is best for your home and budget.
