How do I choose the best water heater?

Author: Rointe


Need some help choosing the right hot water heater for your home? Here’s our practical guide for selecting the best water heating system for hot water >>


Hot water is used without really thinking about it but is critical to comfort in the home. We turn the tap on and expect hot water streaming out straightaway. We don’t want to waste precious minutes folding the toilet paper into a fancy point whilst we wait for the water to heat up. Nor do we want to experience a sudden cold shower at 6.30 am. Again. Ever. But without a reliable water heating system, you may find these regular occurrences. The difficulty is finding the right water heater to produce hot water all the time, at the right temperature, without breaking the bank.

Selecting the best hot water heaters

First, let’s explain what we mean by domestic hot water or D.H.W. It’s the term coined for heated water intended for human use. The most common are the bath, shower or sink, but it’s also used for cleaning and household appliances like washing machines and dishwashers.

Step 1 – the difference between unvented and vented water heaters

There are two main differences between water heaters: unvented and vented.

Unvented water heaters heat water directly from the mains water supply. This means they benefit from higher pressure/flow rates and more balanced hot/cold water supplies and can be installed practically anywhere. They’re the ideal water heating system for properties with multiple outlets, like kitchens and bathrooms.

Vented water heaters are generally installed over the sink area. They have an open outlet, so rely on a tap or valve opening on the inlet side to displace the hot water stored in the heater. There are ideal for use with single sink needs like in a kitchen, surgery or office.

It’s important to understand the difference, so you can search for the right water heating product for your needs.

Unvented water heater

explanation diagram of an unvented hot water heater

Vented water heater

explanation diagram of a vented hot water heater

Step 2 – understanding the different types of water heaters

When we say “water heater”, many immediately think of the commonly used storage tank method. However, nowadays there are quite a few modern products to choose from:
  • Storage/tank – widely available, these types of water heaters are the most common, installation is fairly straight forward (for a professional) and quite often the least expensive. They include a large water tank that stores hot water for use on demand. The water is heated by either electric heating elements or a gas/propane burner. As it tries to keep a large amount of water hot, sometimes these are not very efficient. Look for units with high levels of insulation that offer ways to time the heating process.

  • Tankless/on-demand/instant – these provide hot water on demand by heating water as it travels through the unit. This makes them quite efficient as you’re only using energy when you need it. Larger households with significant hot water needs can experience issues as a tankless system won’t keep up with demand. However, you can install multiple units to overcome these issues. They don’t take up much space They do cost more upfront than other types of water heaters, but they tend to have longer lifespans to recoup your investment. They are rated in terms of how much water is heated per minute e.g. 4.6 litres/min and should be selected as such opposed to the tank size in a storage water heater.

  • Heat pumps – this style of water heater is unique in that is uses heat in the air and in the ground to heat water. This means that electricity is only used to move heat from the ground or air to the water, making them very energy efficient. Heat pumps can use up to 60% less electricity than traditional water heaters. They can be quite large, so you’ll need more space for heat pumps. Because this water heater style relies on pulling heat from the ground or air around it, it will not work very well in cold spaces like basements or in climates where it is excessively cold for long periods throughout the year. They can also be expensive, but it’s a great investment knowing you’ll spend far less on your heating bills.

Storage/tank water heater

Instant/tankless water heater

Heat pump

Step 3 – consider water heater fuel sources, costs and efficiency

When deciding on a water heater you’ll need to consider fuel costs and the different fuel sources available to heat your H20. This depends on where you live as not all are available to everyone. You might also be able to save money by making a smart fuel choice. Don’t forget, different types of water heaters have differing degrees of efficiency, which is a big part of the cost-saving equation.

  • Electric – widely available and works well with conventional tank-type designs as well as tankless water heaters and heat pump systems. Modern electric water heaters are also extremely efficient as they convert all energy they use into heat for the water. Electrically powered water heaters heat using coiled elements and then act intermittently to maintain a pre-set temperature, therefore minimising energy wastage. They also don’t require as much maintenance as your typical gas heater.

  • Gas – commonly used to heat water and space, gas is considered the cheapest fuel source currently, but not the most efficient or ecological. Cold water enters the bottom of the tank, where it’s heated by a gas burner ignited by a pilot light. As the water warms, it rises and is drawn off into a discharge pipe ready for use.

  • Solar – water is pre-heated naturally by the solar panel and use a heat-conducting fluid to transfer this solar energy to the hot water tank through a heat exchanger. You’ll need more space and solar panels, therefore these types of heaters can be more expensive to install. That being said, you can expect a significant saving on your heating bill and greater efficiency, particularly in locations where warmth and sun are prevalent.

  • Geothermal – usually used with a heat pump system that can heat both air and water. This can be extremely efficient. geothermal systems use the ground as their main source of energy. They can transfer heat to radiators and other climate control systems in your home, and provide hot water. Many of these systems can also be used in reverse in hot weather to provide geothermal cooling.

Step 4 – choosing the right size or capacity

Choosing the right tank, cylinder size or water heating capacity depends on a number of factors like the number of users in the household, types of hot water use and the property your water heating system is to be installed in.

Due to a large number of hot water cylinders available on the market, choosing the right one can be daunting. We make this easy for you with our simple guide to Rointe hot water heater sizing, so you can select the correct capacity for your needs:

USERSUSENECESSARY CAPACITYROINTE PRODUCT
1Sink / ShowerInstant | 4 – 15 litresVenice Compact | Capri Instant
2Sink / Shower80 – 100 litresRome WiFi | Siena Digital | Geneva basic
3Sink / Shower / Bath150 – 200 litresRome WiFi | Siena Digital | Dalis Heat Pump
4Sink / Shower / Bath150 – 200 litresRome WiFi | Siena Digital | Dalis Heat Pump
5Multiple Sinks / Showers / Bath260 litresDalis Heat Pump
6Multiple Sinks / Showers / Bath260 litresDalis Heat Pump

When you’re deciding how to approach the purchase and installation of a water heater it’s important to tap into the expertise of experienced professionals with the knowledge to apply the right solution for your home. Contact our team and we’ll help find the best way to keep your water hot and your family happy.

Buy Rointe water heaters now

Learn more about our range of electric heating systems including: radiators, towel rails, domestic hot water heaters, underfloor heating and smart heating controls.

You can also buy Rointe heating systems now from our online shop.


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