conventional-system-boiler diagram

So, your trusty boiler has finally decided to call it quits. Don’t panic! Replacing your boiler might seem daunting, but with MML Plumbing, the process can be smooth and efficient, and you can get your home toasty warm again in no time. But a crucial question remains: how long will it take to get my new boiler installed?

Unveiling the Timeline for a Warm and Efficient Home

The answer to “how long does it take” to fit a new combi boiler, for instance, depends on a few factors. However, this article will give you a clear picture of the typical timeframe for boiler exchange in North London, categorised by boiler type and installation complexity. We’ll also delve into the services MML Plumbing offers to ensure a seamless boiler installation experience, maximising your comfort and minimising disruption. Plus, we’ll explore some money-saving tips to keep your new boiler investment budget-friendly.


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Your Central Heating System Explained: Keeping Your Home Cosy

A central heating system acts as the heart of keeping your home warm and comfortable, especially during colder months. It works by generating heat in a central location and then distributing it throughout your house using a network of pipes and radiators.

Here’s a breakdown of the key components:

Boiler: This is the powerhouse of your system. It burns fuel (gas, oil, electricity, etc.) to generate heat. Common boiler types include gas combi boilers (providing both heating and warm water) and gas/oil heat-only boilers (paired with a cylinder for warm water needs). To install a new boiler, it is crucial to hire a gas-safe engineer to make sure it is installed according to gas safety regulations. ( UK gas safe regulations)

Fuel Source: The boiler relies on a fuel source to generate heat. Common options include natural gas, liquefied petroleum gas (LPG), heating oil, or even electricity.

Pipework: A network of pipes carries warm water from the boiler to radiators throughout your house. These pipes are typically made of copper or plastic and are insulated to minimise heat loss.

Radiators: These are the heat emitters strategically placed in each room. The water flows through the radiators, warming the metal fins, which then radiate heat into the surrounding air.

Controls: A thermostat regulates the temperature in your home. You set the desired temperature, and the smart thermostat then communicates with the boiler to turn it on or off accordingly. Some systems also include thermostatic radiator valves(TRVs) that allow you to control the temperature in individual rooms.

Gas supply pipe: A gas supply pipe delivers natural gas or LPG, to appliances like boilers and heaters, crucial for their operation. Proper installation and maintenance by qualified professionals are essential to preventing safety hazards such as gas leaks.

heating unit completed installation in London

Benefits of a central heating system


Comfort and warmth: Central heating provides a consistent and efficient way to keep your entire home warm throughout the day and night.

Efficiency: A- A-rated modern boilers are highly efficient, converting most of the fuel they burn into heat, minimising energy waste and potentially lowering your heating bills.

Controllable: Thermostats and TRVs allow you to regulate the temperature in your home and individual rooms, ensuring comfort and potentially saving energy.

Central control: The central location of the boiler simplifies maintenance and servicing.

Considering a central heating system upgrade?

Whether you’re experiencing boiler problems or looking for a more efficient current heating system solution, MML Plumbing can help. We offer a wide range of central heating services, from boiler installs and repairs to system upgrades.

Contact MML Plumbing today and let our experienced engineers ensure your home stays warm and comfortable all year round!

Get a Free Boiler Installation Quote Today

Get a free quote today and take the first step toward resolving your heating system needs. Reach out now to discover how we can assist you with reliable services at competitive rates.

To fit a new boiler – Timeframes:

Here’s an estimated timeline for boiler replacements based on different boiler types:

1. Electric boiler exchange (4-6 hours):

Electric boilers are generally the simplest to install, often taking between 4 and 6 hours. This is because they don’t require a flue or gas connection, simplifying the process. However, consider the availability of your existing electrical wiring and any upgrades needed. Upgrading your electrical system might add time to the installation.


2. Gas boiler system conversion to an electric boiler ( 1 day +).

Converting a gas boiler system to an electric one typically takes longer than a standard replacement boiler, ranging from a full day to several days, depending on the complexity.


3. Gas Combi Boiler Exchange (4-6 hours):

Gas combi boilers are a popular choice in London homes, as they provide both heating and hot water. Replacing a combi boiler with a new energy-efficient combi boiler typically takes around 4–6 hours. This assumes a straightforward swap, with existing pipes and boiler flue connections readily accessible. So getting a new combi boiler is relatively quick.


4. Gas Heat-Only Boiler Swap (4-6 hours):

Similar to gas combi boilers, replacing a gas heat-only boiler (often paired with a separate hot water cylinder) usually takes around 4-6 hours. Again, this timeframe is based on a straightforward swap with existing pipework and flue connections.

5. Gas System Boiler Swap (1-2 days):

Gas-system boilers offer superior warm water flow and pressure compared to heat-only models. However, their installation can be more complex, often taking 1-2 days. This is because they might involve rerouting pipework, installing a new cylinder, or connecting to a separate water storage tank.

6. Boiler Conversion Timeline:

Simple Swap: Like-for-Like swap to existing system (1-2 days): Converting from a gas combi boiler to a new combi boiler (or vice versa) might be relatively quick, taking around 1-2 days. This assumes the existing pipes and flue connections are compatible with the new boiler.

Simple Swap ( New Location, Different Location Within Home: 1-2 Days): If the new boiler location is within your home but requires some new pipework or adjustments to reach existing connections in the central heating system, the timeframe might extend to 1-2 days. Our experienced engineers will work efficiently to minimise disruption while ensuring a safe and proper installation.

Moderate Complexity (2–3 days): Converting from a gas heat-only boiler to a new combi boiler, or vice versa, can be more involved. It might require additional pipework modifications and potentially installing a storage tank. This could take 2–3 days.

Significant Complexity (3-5 days or more): The most complex conversions involve switching from a completely different fuel source (e.g., from oil to gas) or installing a system boiler with extensive pipework rerouting and cylinder integration. These projects can take 3-5 days or even longer, depending on the specific requirements.

new radiator and central heating install

Factors Affecting Conversion Time:

Current pipework and flue compatibility: If significant modifications are needed, it will add time. ( if new gas pipes need to run)

Cylinder installation or removal: If the cylinder is required for the new system, it adds to the timeframe.

Fuel source change: Converting from one fuel type (like oil) to another (like gas) or from gas to electric requires additional considerations and permits, extending the process.

Unforeseen complications: As with any plumbing work, unexpected issues might arise, slightly extending the timeline.

Factors Affecting the Boiler Swap Time:

While the above timeframes provide a general guideline, several factors can influence the actual duration:

Boiler accessibility: Easily accessible boilers with readily available connection points will be quicker to replace.

Complexity of existing pipework: Extensive modifications or rerouting of pipes might add installation time.

Flue needs: If a new flue needs to be installed or the existing one requires modification, it can extend the timeframe.

Electrical upgrades: For electric boilers, upgrading your electrical wiring might be necessary, adding time.

Unforeseen complications: During the installation of gas supply pipes, unforeseen issues like hidden pipe damage might arise, extending the process slightly.


MML Plumbing: Your Partner for Efficient Boiler Installation in London

At MML Plumbing, we prioritise efficiency and transparency. Our experienced and Gas Safe-registered engineers will:

  • Conduct a thorough pre-installation survey. We’ll assess your existing boiler, heating system, and potential challenges to provide an accurate timeframe and cost estimate upfront online! If you require a visit, it is chargeable.
  • Offer expert advice: Our team will help you choose the right boiler type for your needs and budget.
  • Handle all aspects of the installation: From disconnecting your old boiler to commissioning your new one, we take care of everything. removal of the old boiler, new boiler fitted, chemical flush, * this is not power flushing! fitting of a new smart thermostat, fitting of a new CO2 alarm (avoid carbon monoxide poisoning), and, upon agreement, fitting new radiators, making the old boiler system more efficient, or a new gas pipe if needed)
  • Signing with Confidence: Once you’ve chosen the perfect boiler for your needs and budget, signing the contract is a simple step. From that moment on, MML Plumbing takes care of everything.
  • Dispose of your old boiler responsibly. We’ll ensure the safe and eco-friendly removal of your old boiler.
  • Provide a comprehensive warranty. Enjoy peace of mind with our warranty on boiler installations.

Money-Saving Tips for Your Boiler Install:

heating system fault finding

Investing in a new boiler is an important financial decision. Here are some ways to save money:

Get a quote: Get a quote today and breathe easy, knowing you’re one step closer to a warm and worry-free winter.

Choose the right boiler size: A boiler that’s too powerful for your needs will be less efficient and cost you more in the long run.

Regular maintenance: Regular boiler servicing by MML Plumbing helps prevent breakdowns and extends the lifespan of your boiler, saving you money on repairs in the long term.

What happens on the day of the installation?

Our experienced engineers will arrive on time and ensure a smooth and efficient installation process. Here’s a general overview:

  1. Safety checks: We’ll prioritise safety by conducting the necessary gas and electrical checks.
  2. Disconnection of the old boiler: We’ll carefully disconnect your old appliance.
  3. Installation: Our team will expertly install your new boiler, ensuring proper connections and functionality.
  4. System testing and commissioning: We’ll thoroughly test your new boiler and heating system to ensure everything is working perfectly.
  5. Demonstration and handover: We’ll provide a clear demonstration of your new boiler’s operation and answer any questions you may have.
  6. Safe disposal of an old boiler: We’ll responsibly dispose of your old boiler, following all environmental regulations.
new radiator and central heating install


Question not answered? Ask A Question by email

The cost depends on the type of boiler, brand, size, and complexity of the installation. However, at MML Plumbing, we offer competitive rates to ensure your investment is budget-friendly. We’ll provide a transparent quote.

We understand that brand choice is important. MML Plumbing is a certified installer for a wide range of leading brands, including:

  • Worcester Bosch
  • Viessmann
  • Ideal Boilers
  • Vaillant
  • Baxi
  • Glow-worm

We can recommend the best brand and model based on your specific needs, budget, and desired features.

While your presence isn’t mandatory throughout the entire process, we recommend being available at the beginning and end of the installation. This allows you to discuss any questions or concerns with our engineers and receive a handover of your new boiler’s operation.

MML Plumbing prioritises minimising disruption during your installation. We:

  • Use dust sheets to protect your floors and furniture.
  • Disconnect your old boiler carefully.
  • Dispose of your old boiler responsibly.
  • Clean up thoroughly after the installation.

While some dust might be inevitable, we take all necessary measures to keep your home clean and tidy.

The cost of a boiler replacement depends on several factors:

Boiler type: Gas combi boilers are generally more expensive than electric boilers.

Boiler brand and model: Different brands and models have varying price points.

Complexity of installation: A straightforward swap might be more affordable than a system conversion requiring extensive pipework modifications.

Disposal of an old boiler: Proper disposal adds to the overall cost.

By choosing MML Plumbing for your boiler replacement in North London, you can expect a professional, efficient, and transparent service. We’ll ensure your new boiler is installed quickly and correctly, keeping your home warm and comfortable for years to come. Contact MML Plumbing today for a free online quote and experience the difference!

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