How to Drain and Refill Your Water System

If you intend leaving your home or property unoccupied for a lengthy time during the winter months, it is advisable that you know how to drain and refill your water system. Failure to drain your water system may result in your pipes freezing while you are away, which could cause them to split and burst, leaving you with a nice expensive repair job when you return.

You can drain your complete water system by following these simple steps:

  • Switch off the main boiler or emerging heating units.
  • Rake out any solid fuel boilers and give them time to cool down.
  • Switch off your main stopcock located on your rising main, and then run off all the water coming from all of the hot and cold taps.
  • If you have a drain cock located on the rising main itself, drain any water in the pipe using that drain cock.
  • Flush your toilets.
  • Drain your hot water cylinder.

You do not have to drain all the water from your central heating system, however, you could make sure that the system contains some antifreeze. If where you live it tends to get very cold, it may be wise to add some salt to your toilet pan in order to prevent the water in the trap and u-bend from freezing.

Refilling your system

In order to refill your system, make sure you close all the taps and drain cocks, once this has been done open your main stopcock. Once the system starts to fill, make sure that the float valves are working properly.

Any trapped air in the system might cause the taps to gurgle and splutter until the air is forced out. If the air does not clear the system naturally, you may have to remove it using the mains pressure.

Curing an airlock

A simple way to remove trapped air from inside your water system, is to attach a piece of hose pipe to both the hot water and cold water taps in your kitchen as the cold tap is connected directly to the mains.

Turn on the hot tap and then the cold tap and leave them turned on for a few minutes. The pressure from the cold water mains should blow the airlock out of the hot tap.

You may have to repeat the process a couple of times until the water starts to flow freely from both taps.