Is It Normal for unvented or Thermal Store Water Cylinders to Have Condensation?

Your unvented cylinder holds heated water inside it until you’re ready to use it. However, what if you notice water outside the cylinder? Specifically, is condensation normal for unvented cylinders?In a word, yes. Condensation can be normal. However, there are instances when it can be a sign that there’s something wrong. In this blog post, we’ll explore what you need to know so you can make an informed decision if you notice condensation on your unvented cylinder.

In most circumstances, you should not see any condensation on the outside of your unvented cylinder. However, there is one exception – when the incoming water from the mains is very cold. When very cold water enters the cylinder, the combination between heat and cold can cause some condensation to form on the sides of the cylinder. For instance, you may notice this happens during the depths of winter when the incoming water from outside your home is at its coldest.

This will be most common when you’ve gone through all the heated water in the cylinder or when filling a cylinder for the first time.

If you’re experiencing seasonal condensation, there is nothing you need to do to correct the situation.

Another reason to see condensation on your unvented cylinder is if your thermostat is set too low. Thankfully, this is a simple fix. Just increase the temperature on your thermostat and you should notice the condensation vanish. Note that this will also help protect your unvented cylinder against problems like bacteria colonising it and causing foul odours.

Condensation can be easy to mistake for a leak, particularly if it is heavy and rolls down the sides of the cylinder to the base and begins to pool there. How do you tell if you’re seeing condensation, rather than water seeping from an internal leak? Here are a few simple steps to help give you peace of mind.

• Dry the water under the cylinder completely.
• Turn the thermostat off if electric or to “pilot” if it’s gas-fired.
• Wait for the water in the tank to cool completely. Note that this can take a couple of days.
• Inspect the cylinder for any signs of water. If you notice water on the surface of the cylinder or at the base at this point, you should suspect a leak.
• Call the professionals at EasyFlow to inspect your cylinder, locate the leak, and repair or replace it as necessary.

A leaking unvented cylinder is an accident waiting to happen. In some cases, they can explode. Even if the worst-case scenario does not happen, you could still be facing costly water damage if the leak affects the surrounding areas of the home.

At EasyFlow, our certified plumbers can inspect your unvented cylinder, repair it if possible, or recommend a replacement if that’s necessary. We can also offer annual maintenance plans to ensure that you’re never surprised by these types of problems.