Understanding hot water systems

1 December 2016
 Categories: , Blog

Winter is the toughest time of the year where the cold penetrates into your bones and chills you. It is important to ensure that your home is heated and also the homes of your loved ones, especially for any elderly relatives you may have. To do this properly it is vital to have some understanding of the different hot water systems that are available and the pros and cons of them all. This allows you to weigh up which hot water system it is beneficial to have in your own home or the home of a loved one that you are looking out for.

Basic systems

The first thing to understand is that there used to be just two main types of hot water system, these are direct and indirect heating. Direct heating is when the water is heated directly by the heat source, examples of this would be an immersion heater or boiler. Indirect heating is when the water and central heating are separate. In indirect systems a coil is heated directly from the boiler and therefore indirectly heats the water. These are both known as vented systems.

System identification

A direct water system can be identified easily by finding a vent pipe that will be fixed above your cold water tank.  An indirect system will have two water tanks, making it even easier to identify. What complicates matters in identifying your heating system is the other models of heating which are available. You can have any of the following:

  • An unvented system - This operates solely from the mains water, but the principles of heating are similar.
  • A thermal store system - This innovative new system has been developed in Britain—it's the indirect heating principle in reverse, since the boiler heats the water, sends it to the cylinder then onto the central heating.
  • A single point water heater - Works on a thermostat and can be electric or gas based—when the tap is drawn the burners are ignited and the hot water rises to the top.
  • A multi point water heater - More commonly known as combination boilers, they work on the same principle as single water heaters but with access to many different points.


You can also explore what type of water heater would suit you by what type of energy was fuelling it. As we've already mentioned, it can be electric or gas, but there are many other energy sources available nowadays. These include geothermal energy, propane, fuel oil and solar powered energy. The latter is becoming more and more readily available and prevalent as a heating option.

Best system for you

It depends what aspect is most important to you when choosing the best hot water system—whether it is it energy efficiency, cost or ease of use. If you're not going to be drawing two streams of water at once, showering whilst using the washing machine for example, then going with one of the tankless models might be a good idea. But, if you're hoping for an electric system these can be costly. There are many questions to consider, so hopefully this is a good start to understanding the options that are available to you.