How to Size a Hot Water Cylinder Replacement

It has served your family well for many years, but it has finally given up the ghost – your water heater has failed. Now it’s time to replace it. While you may decide that going with a replacement cylinder of the same size is the best idea, you may also find that it’s time to change sizes. How do you determine the right size for your needs?

First, let’s consider why you might want to change sizes in the first place? Why not just go with an identical replacement cylinder? There are two factors at play here – the available supply of hot water and the cost that you pay for that hot water. The larger the cylinder, the more hot water it will hold. However, the larger the cylinder, the more it will cost to operate.

The first thing you need to consider when choosing a replacement hot water cylinder is the amount of demand your household will have at its peak. That is, how much hot water will be needed during your peak hour demand? For many households, this is first thing in the morning when everyone is getting up, getting showers before work or school, making breakfast and the like.

• Shaving (.25 litres per minute)
• Showering (at least 45 litres per shower)
• Dishwasher (25 litres per use)
• Hot water clothes washing (30 litres per use)
• Washing hands (5 litres per minute)
• Food prep (5 litres per minute)

You’ll need to take those numbers and figure out how many times each is used per hour in your household. This will then allow you to determine the number of gallons used per hour. Based on that, you can choose a water heater of the right size for your needs.

In some instances, your household’s demand for hot water will change over time. For instance, your children will grow up and go away to school, or get married and start their own families. In other instances, you might have more children later in life. You could go through any number of other life changes that alter the number of people within your home, and your hot water usage will change, too.

The more people in a household, the more hot water you’ll need on hand at any particular time. The converse is true, as well. For instance, if you’re replacing a water heater after you’ve retired from work, and your children have started families of their own, you will need far less hot water on hand, allowing you to choose a smaller cylinder with a lower volume to save money.

And of course there are the minimum sizes based on the number of bedrooms and bathrooms to consider 

Ultimately, the best option is to work with an expert in water cylinder replacement. If your old water heater is beginning to show signs of its age, or it has failed already, we invite you to contact EasyFlow for an estimate on a replacement of the right size and capacity for your needs. Call us at 0161 941 5571.