Tank vs Tankless Water Heaters: Which Is Best for Your Home?
A reliable supply of hot water is needed in any household for individual washing and showering, clothes washing and general cleaning. Traditionally, water has been pre-heated, stored in a tank and then delivered by pipe to an outlet where it is required. A more modern method is to use a tankless system where hot water is provided when it is needed.
Both systems have their advantages and drawbacks, which causes a regular tank vs tankless water heater debate. To decide which is best, you need to consider your particular circumstances before making your choice.
Features of Tank and Tankless Hot Water Systems
Traditional hot water systems have a tank that stores hot water ready for use. The connected heater will constantly heat up the water as the temperature drops, especially when hot water is used, so it is always maintained at a set temperature.
The water may be kept hot by an electric heater, where the heating element is a rod through the middle of the tank or is at the top and bottom, or a gas heater that is powered by natural gas or propane and heats the water from the bottom. Both types of system work automatically, turning on when the temperature of the water falls below the set level.
The hot water tank is often insulated to prevent too much heat being lost. Sometimes, there may also need to be a header tank, generally located in the loft, that delivers cold water into the hot water tank. This may be necessary if the water pressure is low and ensures there is always sufficient water in the system as well as acting as an expansion tank for the heated water.
A tankless system does not pre-heat and store hot water ready for use. Instead, it heats the water to a set temperature at the time it is needed. Turning on a hot tap will activate the heater, which again can be electricity or gas powered. The former has a heating element positioned immediately before water enters the pipes while the latter ignites a gas flame that heats the water.
Earlier tankless heaters were non-condensing, which means they only had one heat exchanger and some heat energy was lost with the exhaust fumes. More modern condensing systems direct the exhaust gases into a second heat exchanger where the vapour condenses and produces additional heat, making the process more efficient.
Benefits and Drawbacks of a Tank Water Heater
A tank water heater has several benefits:
- Since the technology has been around for longer, it is familiar and so can be easier to install.
- A new system is cheaper to buy and install than a tankless system.
- Since the water is pre-heated and stored, hot water will still be available even during a power outage.
- It is better able to support multiple concurrent users than a tankless system that may not be able to cope with the volume.
- Maintenance and repairs are usually simpler.
However, there are a number of drawbacks compared to a tankless system:
- The hot water tank has a limited capacity and so may be drained by periods of heavy use, causing delays while fresh water is heated.
- Space is needed for the hot water tank and possibly for an additional header tank.
- Since water in the tank will inevitably cool, even if insulated, it needs to be periodically re-heated and so energy costs are higher.
- Systems tend to have a shorter lifespan and higher maintenance costs. This is partly due to tanks that can suffer corrosion, with the potential for bursts and water damage.
Benefits and Drawbacks of a Tankless Water Heater
The benefits of a tankless system include the following:
- Since water is produced on demand, there is an endless supply.
- Water is only heated when needed so energy costs are lower.
- Systems usually have a longer life with lower maintenance costs.
- With no tank need, more space is available.
- More modern technology tends to be easier to use.
There are, however, some drawbacks:
- Upfront costs tend to be greater, with a higher purchase price and a more complex installation process that may require supply upgrades.
- Maintenance costs may be higher due to the increased complexity of the system.
- Systems may not be able to cope with high demand and so more than one heater may be needed in large homes.
Choosing the Most Suitable Type of Water Heater
The best choice for you will depend on your particular needs and preferences. If you have a limited budget, a tank system will be cheaper to buy and install but will cost more to run. You also need to ensure you have a suitable space for the hot water tank and possibly an additional header tank.
A tank heater is probably better for smaller households with limited demand that will not exceed the capacity of the tank. However, a tankless system provides unlimited hot water and so is more suitable where there is high demand. Also choose a tankless system if you value lower energy costs and want a system that lasts longer.
We can help you in your choice because we have wide experience of all types of heating systems and know which ones work best in certain situations. And, once installed, we can keep your system running perfectly with no problems due to a programme of regular serving and maintenance. Get in touch for the best advice and service.











