Dealing With Airlocks in Your Hot Water System: 2 Solutions

Posted on: 29 November 2017


If you hear a loud hissing sound or see bubbles in the water when you turn on the hot water taps in your home, it is highly likely that you are experiencing a very common plumbing problem called an 'airlock'. Airlocks happen when air becomes trapped in the pipes of your hot water system. This air makes it difficult for water to move around the system and results in hissing and bubbles. Thankfully, fixing an air lock issue is relatively easy. Below is a guide to 2 methods you can use.

Bathroom Tap

The course of action you need to take will depend on the type of tap you have installed in your bathroom. You will either have two separate hot, and cold taps which are supplied by different pipes or you will have a single mixer tap, which is connected to both the hot and the cold water supply.

If you have separate hot and cold taps, you will need to attach one end of a section of hose to the hot tap and the other end to the cold tap. You should apply waterproof tape to the edge of the tube to help to create a watertight seal. You should then turn on both taps. The cold water which is coming from the public supply is typically under more pressure than the water coming from your hot water tank so it will force any air which is trapped in the hot water system out.

If you have a single mixer type tap, you should ensure it is in the central position, so it opens both the cold and hot water valves. As the water starts to come out of the nozzle, you should cover it with your thumb. Doing so will force the higher pressure cold water back into the hot water pipe. This increase in pressure should remove any trapped air. You should be aware that placing your thumb over a running tap is likely to create a short spray of water so you should be prepared to get a little wet.

Washing Machine

Alternatively, you can use your washing machine to clear an airlock. Your washing machine will be fitted with two hoses, one from the hot water system and one from the cold water supply. Simply turn the vales on these hoses to cut off the water supply. Disconnect the hoses from the back of your washing machine and attach them together using waterproof tape. You can then turn both valves back to the open position. This will send high-pressure water into the hot water system to clear any trapped air.

If air blocks are repeatedly forming in your hot water system, this could be a sign that there is a bigger problem with your plumbing so you should call in a professional plumber.