Megaflo Unvented Boiler Systems: Everything You Need to Know

Welcome to our guide on Megaflo unvented boiler systems. If you’re considering a Megaflo system for your home, you’ve come to the right place. In this article, we will delve into the details of Megaflo boilers, their functionality, pros and cons, and associated costs. Our aim is to provide you with valuable insights that will help you make an informed decision for your heating and hot water needs.

Understanding Megaflo: An Introduction

The Megaflo system, often mistakenly referred to as “Megaflow,” is a remarkable hot water cylinder made of stainless steel. As an unvented system, it stores and distributes hot water as part of your central heating system. It’s important to note that the Megaflo system is not a boiler replacement but rather a companion to a system boiler. By combining the power of a system boiler with a Megaflo cylinder, you can experience unparalleled hot water performance.

Is a Megaflo System Right for You?

To determine if a Megaflo system is suitable for your home, consider the following factors:

  1. High Hot Water Demand: If you frequently use multiple baths and showers simultaneously or require a high flow rate of over 16 liters per minute, a Megaflo system is ideal for meeting your hot water needs.
  2. Water Pressure: Megaflo systems thrive in households with high water pressure requirements. If you have high-pressure demands and ample storage space for the cylinder, a Megaflo system is an excellent choice.
  3. Hydrogen Ready Boiler: If you’re considering a new system boiler, ensure it is hydrogen-ready to comply with the gas boiler ban in 2025. Pairing a hydrogen-ready system boiler with a Megaflo cylinder ensures a future-proof and environmentally friendly heating solution.

Exploring Megaflo System Prices

When investing in a Megaflo system, it’s crucial to understand the associated costs. Here’s a breakdown of the expenses you can expect:

  1. Megaflo Cylinder: The cost of a Megaflo cylinder, also known as a Megaflo tank, typically ranges from £500 to £1500. Prices may vary depending on the capacity and specific model you choose.
  2. Megaflo System Boiler: A Megaflo system boiler paired with an unvented cylinder can cost between £1,000 and £3,500. Be sure to inquire whether the price includes VAT and installation fees.
  3. Installation Costs: Unvented hot water cylinder installation can range from £500 to £2,000, depending on the complexity of the work required for the boiler installation. It’s advisable to obtain a detailed quote from a qualified installer.

Understanding the Megaflo System in Detail

Differentiating Between Indirect and Direct Unvented Megaflo Systems

Megaflo systems come in two variations: indirect and direct. Let’s explore their differences:

  1. Indirect Unvented Megaflo: In this configuration, the hot water supplied by an external source, such as a regular or system boiler, heats the water stored in the cylinder. The cylinder’s coil ensures the water temperature remains consistent based on the thermostat settings. When hot water is used, the boiler refills the cylinder to maintain an ample supply.
  2. Direct Unvented Megaflo: This type of Megaflo system utilizes the mains cold water supply as its primary source. Inside the cylinder, a Megaflo immersion heater switch, powered by electricity, heats the water to the desired temperature defined by the thermostat. When hot water is drawn, the system replenishes the supply with cold water from the main feed.that both indirect and direct unvented Megaflo systems offer reliable and efficient hot water solutions for your home. The choice between the two depends on your specific requirements and preferences.

Manufacturers of Megaflo Boilers

The Megaflo range is manufactured by Heatrae Sadia, a reputable company known for producing high-quality hot water cylinders and storage water heaters. You may also come across Megaflo systems referred to as Baxi Megaflo, as Baxi Boilers is the parent company of Heatrae Sadia. The Megaflo range has gained popularity due to its ability to meet the increasing hot water demands of modern households. Heatrae Sadia takes pride in offering reliable and efficient products that balance performance and energy efficiency seamlessly.

Advantages of a Megaflo Boiler System

Investing in a Megaflo system comes with several benefits, including:

  1. Space-saving Design: Megaflo systems eliminate the need for a large loft-installed tank, saving valuable space in your home. With no requirement for a cold water tank, you have more flexibility in choosing the installation location for your Megaflo cylinder.
  2. Easy Installation and Maintenance: Megaflo systems are designed for easy installation, and their components are readily available for replacement and maintenance. Regularly inspecting and maintaining the system ensures optimal performance and longevity.
  3. Compatibility with Renewable Energy: In the event of a boiler breakdown, the Megaflo system is compatible with solar PV, providing a renewable energy source and ensuring a backup solution for hot water needs.
  4. Enhanced Water Pressure: Megaflo systems utilize mains pressure, resulting in improved water pressure for your showers and baths. Even in busy households with multiple outlets in use simultaneously, the Megaflo system delivers a satisfying high-pressure shower experience.
  5. Safety Features: Megaflo systems incorporate various safety features, such as a cylinder thermostat that shuts down at the correct temperature and a Temperature/Pressure Relief Valve that regulates pressure by releasing water if necessary. These safety measures provide peace of mind for homeowners.

Considerations and Limitations

While Megaflo systems offer numerous advantages, it’s important to be aware of some considerations:

  1. Mains Water Pressure: If your mains water pressure is low, it may impact the water pressure delivered by the Megaflo system. To assess suitability, consider having a flow rate test conducted by engineers to determine if the system can meet your requirements.
  2. Potential Noise: The high velocity of water flowing through the pipes in a Megaflo system can generate noise. Proper inspection of the existing pipework’s capability to withstand the pressure is essential. Replacing pipes to accommodate a Megaflo system can incur additional costs.
  3. Continuous Water Supply: As Megaflo systems rely on the mains water supply, a consistent water pressure is necessary to ensure an uninterrupted hot water supply. Any interruptions in the mains water flow may result in a temporary shortage of hot water.

Megaflo Warranty and Longevity

Water hardness varies across different regions in the UK, making a robust warranty essential. Heatrae Sadia offers a remarkable 25-year warranty on all Megaflo hot water cylinders, reflecting their confidence in the quality and durability of their stainless-steel unvented cylinders. This warranty provides peace of mind, especially considering the potential longevity of a Megaflo system.

It’s important to note that other components of your unvented boiler system may have shorter warranties compared to the extended warranty offered on Megaflo cylinders. Be sure to consult with your installer or supplier to understand the warranty coverage for each component.

Megaflo Pressure for Large Households

If you have a larger household with multiple bathrooms and outlets, you may wonder if the Megaflo system can meet your hot water needs. Rest assured, the Megaflo system is more than capable of providing for larger households with high hot water demands. Its robust design and efficient heating capabilities ensure a steady supply of hot water throughout your home.

With a Megaflo system, you can enjoy the convenience of simultaneous hot water usage without compromising water pressure or temperature. Whether you’re running multiple showers, filling a bathtub, or using various outlets at the same time, the Megaflo system rises to the occasion, delivering reliable and consistent performance.


In conclusion, a Megaflo unvented boiler system offers exceptional hot water solutions for your home. With its innovative design, space-saving features, and compatibility with renewable energy sources, it provides a reliable and efficient heating solution.

Before making a decision, consider factors such as your hot water demands, available space, and water pressure. It’s advisable to consult with qualified professionals to assess your specific requirements and ensure a seamless installation process.

Remember, investing in a Megaflo system not only enhances your hot water experience but also offers long-lasting reliability and peace of mind with its extensive warranty coverage.

If you’re ready to experience the benefits of a Megaflo unvented boiler system, don’t hesitate to explore your options and obtain a fixed online price for your new boiler.

Get an online fixed price for your Megaflo system now and embark on a journey of superior hot water comfort for your home.

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