Skip to content 
A hot water cylinder is an essential household appliance that provides hot water for various domestic needs, including bathing, washing dishes, and laundry. Over time, hot water cylinders can deteriorate due to factors like wear and tear, corrosion, or mineral build-up. When your hot water cylinder reaches the end of its lifespan or becomes inefficient, it’s time to consider replacement or up-gradation.
What is Hot Water Cylinder
A hot water cylinder or water heating cylinder is a tank that stores heat and hot water. These cylinders are available in different capacities mostly between 90 and 300 litres based on the amount of hot water used in the household.
There are two main types of hot water cylinders:
- Vented Cylinders
- Unvented Cylinders
1. Vented Cylinders
Vented cylinders are connected to a cold water tank which is normally located in the loft and depends on gravity to deliver hot water.
2. Unvented Cylinders
Unvented cylinders are directly connected to the mains water supply and hence they deliver higher pressure of hot water and no cold water storage tank is required.
The choice of type depends on the water pressure, space, and the home’s plumbing system among other factors.
Energy Efficiency and Cost Considerations
Energy efficiency plays a crucial role when deciding to upgrade or replace a hot water tank. Modern cylinders offer improved insulation and more efficient heating mechanisms, resulting in lower energy consumption and reduced bills. For example, upgrading to an A-rated hot water cylinder can save up to 20-30% on energy costs compared to older models. Additionally, the initial cost of replacing a hot water tank varies depending on the type, size, and installation requirements. On average, the cost ranges from £500 to £1,500, including installation. However, investing in a higher-efficiency model can lead to substantial savings over time, making it a cost-effective choice in the long run.
Type of Tank | Average Cost (Including Installation) | Energy Efficiency Rating | Estimated Annual Savings |
Standard Vented | £500 – £800 | C – D | £100 – £150 |
Unvented | £800 – £1,200 | A – B | £150 – £250 |
Solar Thermal | £1,000 – £1,500 | A | £200 – £300 |
Types of Hot Water Cylinders
Before making a decision, it is essential to understand the type of hot water cylinder you currently have. Common types include:
- Storage cylinders: These store heated water for later use. They come in various sizes and insulation levels.
- Instantaneous cylinders: These heat water on demand and don’t require storage. They are ideal for smaller households with limited space.
- Combi boilers: These combine central heating and hot water functions in a single unit.
Benefits of Upgrading to a Modern Hot Water Cylinder
Upgrading to a modern hot water cylinder offers numerous benefits beyond just energy savings. Newer models provide better insulation, reducing heat loss and maintaining water temperature for longer periods. This results in less frequent heating cycles and lower energy consumption. Modern cylinders also come with improved safety features, such as thermostatic mixing valves that prevent scalding by mixing hot water with cold water to achieve a safe temperature. Additionally, upgrading can increase water pressure, especially when switching from a vented to an unvented system, enhancing the overall comfort of showers and baths. These benefits contribute to a more efficient, safer, and comfortable home environment.
Apply for Free Boiler Grants
Replace Your Old Inefficient Boiler With A Rated Condensing Boiler
Check your Eligibility Now
When To Replace Hot Water Tank
Several indicators can signal that your hot water tank needs replacement:
- Age: Cylinders typically last between 8-12 years. If yours is nearing this age, it might be time for an upgrade.
- Leaks: Leaks can indicate damage to the cylinder or its fittings.
- Poor performance: If you notice a significant drop in water temperature or pressure, it could be a sign of a problem.
- Rust or corrosion: Look for signs of rust or corrosion on the exterior or interior of the cylinder.
- High energy bills: An inefficient cylinder can lead to increased energy consumption.
Factors to Consider When Replacing or Upgrading
When choosing a replacement cylinder, consider the following factors:
- Size: The size of your cylinder should match your household’s needs. A larger cylinder will provide more hot water but may be more expensive to run.
- Insulation: Opt for a cylinder with good insulation to minimize heat loss.
- Energy efficiency: Look for cylinders with energy-efficient ratings to reduce your energy bills.
- Type: Decide whether you prefer a storage cylinder, instantaneous cylinder, or combi boiler based on your lifestyle and space constraints.
- Budget: Set a budget for your replacement or upgrade. Prices can vary depending on the size, type, and brand of the cylinder.
Replacement Costs
The cost of changing hot water cylinder can vary significantly depending on factors such as:
Factor | Cost Impact |
Cylinder Size | Larger cylinders are generally more expensive. |
Type | Combi boilers tend to be more costly than storage cylinders. |
Installation | Professional installation can add to the overall cost. |
Location | Costs may vary depending on your geographic location. |
Choosing the Right Size for Your Hot Water Cylinder
The size of the hot water cylinder you choose depends on your household’s hot water demand. For instance, a small family of two to three people may require a cylinder with a capacity of 120-150 litres, while a larger family of four or more might need a 180-210 litre cylinder. Oversizing a cylinder can lead to unnecessary energy consumption, while under-sizing can result in an insufficient hot water supply.
To determine the appropriate size, consider factors such as the number of bathrooms, frequency of hot water use, and whether you have high-demand appliances like power showers or large bathtubs. Proper sizing ensures efficiency and comfort, avoiding both waste and inconvenience.
Installation Considerations and Regulations
Installing a new hot water cylinder requires careful consideration of various factors, including space, plumbing compatibility, and compliance with building regulations. In the UK, installing an unvented hot water cylinder requires a qualified engineer with a G3 certification to ensure safety and adherence to regulations.
The installation location should have adequate space for the cylinder and allow easy access for maintenance and inspection. Proper ventilation is crucial, especially for unvented systems, to prevent pressure build-up and ensure safe operation. It is also essential to install safety devices like temperature and pressure relief valves, which release excess pressure and prevent potential accidents.
Maintenance Tips
To ensure your new hot water cylinder lasts as long as possible, follow these maintenance tips:
- Regular inspections: Conduct regular inspections to check for leaks or signs of damage.
- Scale removal: Periodically remove scale build-up from the cylinder to improve its efficiency.
- Insulation maintenance: Ensure the insulation around the cylinder is in good condition.
- Proper venting: Ensure the cylinder is properly vented to prevent carbon monoxide build-up.
Common Mistakes to Avoid When Replacing a Hot Water Cylinder
Changing hot water cylinder can be a significant investment, and avoiding common mistakes ensures you get the best value for your money. One common mistake is choosing the wrong type or size of cylinder, leading to either inadequate hot water supply or unnecessary energy consumption. Failing to hire a qualified installer can also result in improper installation, voiding warranties and potentially causing safety hazards.
Neglecting to check the compatibility of the new cylinder with your existing heating system can lead to inefficiencies and increased costs. Always consult with a professional and ensure compliance with local regulations to avoid these pitfalls and make an informed decision.
Environmental Benefits of Upgrading Your Hot Water Cylinder
Upgrading your hot water cylinder not only benefits your household but also contributes to environmental sustainability. Modern hot water cylinders are designed to be more energy-efficient, reducing carbon emissions and your home’s overall environmental footprint. Switching to an unvented system, for example, eliminates the need for a cold water storage tank, reducing water waste and improving efficiency.
Additionally, opting for cylinders compatible with renewable energy sources, such as solar thermal systems, further enhances sustainability by harnessing natural energy to heat water. These environmentally friendly choices align with global efforts to reduce energy consumption and promote sustainable living, making them a responsible choice for any homeowner.
Apply for Free Boiler Grants
Replace Your Old Inefficient Boiler With A Rated Condensing Boiler
Check your Eligibility Now
The Bottom Line
Regular maintenance and timely replacement of your hot water cylinder ensure continuous performance and efficiency. Whether you are changing your hot water cylinder due to an upgrade or necessity, understanding the factors involved helps you make the best choice. Prioritising energy efficiency, safety, and professional installation will provide peace of mind and a consistent supply of hot water for years to come. Remember, investing in a high-quality, energy-efficient hot water cylinder benefits your home, finances, and the environment, making it a smart and sustainable choice.
By following this comprehensive guide, homeowners can navigate the process of replacing or upgrading their hot water cylinders with confidence and clarity. With the right approach and considerations, you can enhance your home’s comfort, efficiency, and sustainability.
Frequently Asked Questions
If your hot water cylinder is over 10 years old, frequently runs out of hot water, or shows signs of leaks, it might be time for a replacement. Newer models offer better efficiency and performance.
Vented cylinders rely on a cold-water tank in the loft and generally have lower water pressure. Unvented cylinders use mains pressure, providing higher water flow and pressure, making them ideal for modern homes.
The cost varies depending on the type and size of the cylinder and installation complexity. Unvented cylinders are typically more expensive but offer better performance. Always get a few quotes from professionals to find the best option for your budget.
Get Your ECO4 Grant
Simply enter your postal code and answer a few questions, we’ll handle the rest!
Recent Blogs
Share Blog
