Jim's Plumbing


How to Stop Water Hammer

Steps to Solve Water Hammer

Step 1

Check that there are no leaking taps, toilets, or valves on hot water heaters as this gives a cause for possible hammering throughout the night. If any of these are found to be leaking, then replace them.

Step 2

Pin or fasten any tap washers that may be left in the open position at all times; such as washing machine taps, toilet isolation taps, hot and cold water isolation taps or outside taps that may be connected to timers or irrigation. By flattening the shaft of these washers where they sit in the spindle means that the tap washer will not be jumping around when the tap is open. This is the most common form of water hammer that we do find and definitely can be a cause for the banging of pipework throughout the night.

Step 3

It can be something as simple as the irrigation system that may be on a timer where it turns on or off throughout the night. Most homes have solenoid vales connected to their irrigation which shut off very quickly and abruptly, resulting in pipes hammering. If this is the cause, change the cycle of time that the irrigating is on or off.

Step 4

If your toilet cistern has a slight drip of water going from the toilet cistern into the bowl, the ball valve within the cistern can turn on, creating a banging noise throughout the night. This leak is often undetected as it is not visible. However, we would advise putting a few drops of food colouring into the cistern which will show a slow drip of water into the bowl. Without this food colouring it often cannot be seen. If this is the case, the flushing assembly bottom rubber will need to be changed as this is a faulty rubber where the water is bypassing and the float valve then is refilling the water throughout the night creating the shuttering of pipes.

Step 5

Once finding what the cause of the problem is, the water hammer arrester can always be installed on the offending tap. However, in our experience, this solution is not a guarantee.

Step 6

A pressure limiting valve can be installed at the water meter. What this does is decrease the incoming pressure to the house. It is not a complete solution but it often reduces the noise of water hammer.

Step 7

If you have an electric storage hot water heater which is on a heating tariff that heats through the night, you may find that when the hot relief valve dumps water due to the hot water in the tank expanding while in the heating cycle, that you are then getting the shuttering noise of pipework also. This is a normal operational factor for storage heaters and looking at one of the above issues may assist in alleviating the hammering noise.

Step 8.

We have found that water meters are hammering from the tap washer. Unfortunately, customers and plumbers do not fix this. The water authority should check it and fix it.

Step 9

Check all pipework in the ceiling and walls and saddle support pipework where you can.

If you need assistance with any of these water hammer issues that may be occurring in the middle of the night, please call Jim’s Plumbing. We can have a licensed plumber out to you 7 days week, 24 hours a day!

15 Years of Service
15 Years of Service