Sputtering tap


If a sputtering supply of water comes out of the hot tap, the most likely cause is an airlock in the hot water pipe.

 The mains pressure of the cold water is much greater than that of the hot water, so you can use this to force a bubble of air back up the hot water pipe to the hot water cylinder. There are two ways of doing this.

Say you have a sputtering tap in the kitchen.If your washing machine is connected to a hot and cold water supply, you can fix an airlock quite readily:

  • Turn off the cold water tap at your washing machine and disconnect the hose from the back of the machine.
  • Turn off the hot water tap and disconnect the hose from the tap. Now connect the free end of the cold water hose to the hot water tap. (You should now have the two taps connected to each other by a hose.)
  • Turn on the hot water tap and then the cold water tap. Leave both taps on for approximately 30 seconds (CAUTION: no longer, because you don’t want to overfill the hot water cylinder). This’ll allow the greater pressure of the cold water to push the airlock back up the pipe.
  • Now check the flow at the hot water tap in the kitchen. If there is no improvement, follow the same procedure again. If after three attempts the problem isn’t solved, you‘ll need to call a plumber

Another method is to use the mixer tap in the kitchen (or bathroom). Read all the instructions below before you start.

  • Jam a cloth over the tap outlet and hold it firmly in place with the palm of your hand to prevent any squirting or flowing from the outlet. (Wear your wetsuit just in case!)
  • Turn on the hot tap and then the cold for 30 seconds (make sure it’s in that order to prevent the mains pressure from forcing your hand away). The cold supply will now run through the mixer and across into the hot water pipe, clearing the airlock.

Allow the taps to run for 30 seconds, then turn the cold water tap off first, then the hot.

What temperature should the hot water be? (click here). Adjust the temperature (click here). How to repair a leaking or dripping tap. (click here). Water supply (click here).