Wrong installation of floor heating

Overlooking the conduit

When installers are pushed for time it can be easy to sacrifice the pipe conduit but overlooking the function of this material could have implications post-installation. The conduit acts as a protective sleeve for pipes where they rise from the screed floor up to the manifold, as well as where pipes travel through an expansion strip. Not only does conduit protect the pipework from damage but it also helps to insulate the pipe and prevent an excessive build-up of heat in one area, which can often cause cracks in the floor screed. A little bit more time spent installing conduit on your pipework could well save you a call-back later on.

Bursting under pressure

If there's one piece of advice we like to give plumbers aside from using plastic fittings, it's to always remember to perform a pressure test. Unfortunately, this critical action is often skipped, particularly when installers are in a hurry to move from one job to the next. However, when you forget to perform a pressure test you also forget to expand the pipework. Installers shouldn't automatically expect the UFH system to perform at optimum capacity when the pipes are at their most expanded. We always advise performing a pressure test at 6 bar before flooring or screed is laid. This will allow you to check for leaks and ensure the pipes reach maximum expansion. Make sure you maintain this pressure until the screed has been fully applied, as this prevents the screed from cracking later on.

Carrying out the wrong pressure test

Believe it or not, carrying out a pressure test with air instead of water is a common mistake that many installers make. This will not allow the pipes to hydraulically expand, simply because air can be compressed, whilst water cannot be. It is important to make sure there aren't any traces of air in the system, as air loops in the pipe wouldn't let the system run properly.

Not opening the valves on the manifold when performing a pressure test

Tricky business this pressure testing, isn't it? Even if you remember to perform a pressure test and follow best practice by conducting a test with water rather than air, it is still possible to make a mistake if you do not open the valves on the manifold. Each manifold has two isolation points on each circuit. These are controlled by a decorator cap, which protects the valve. While pressure testing, the cap should be unwound so that it only just sits on the manifold, or removed completely to allow the water in the system to flow. If you forget to remove the cap, you will only pressurise the manifold, not the water. The same is true for the other isolation point, which has a cap on the flow gauge. This must also be open during a pressure test.