Airlock in water pipes

Airlock in water pipes

Hi, and welcome to my latest blog of the day airlock in my water pipes, In the picture to the right of you is a typical Central heating system, If your having trouble with you hot water tap then please go to how to get an airlock out of my tap, but if the airlock is in the central heating then please carry on reading this article.

An airlock in water pipes can be cause by a few different reason starting with the list below.

  1. Central heating pipes not level
  2. Draining down central heating
  3. Small air pocket due to corrosion
  4. Air being pulled in by pump from the expansion pipe more likely in attic
  5. build up of air bubbles over time and not bleeding your radiators

All these must be checked but the best way to get an airlock out is to completely drain the central heating system, as detailed below.

  1. Get an outside water hose pipe
  2. Attach to a drain off valve at end off radiator (If you have one, If not go to answer 11)
  3. Turn off mains stop valve
  4. Open up drain off valve and let drain until system stops draining, (In some circumstance this may take a long time or in other case too long which then is better to get a professional)
  5. Open each radiator on top floor until completely drain then do the same on each floor, (you may not need to do this on the ground floor if each radiator is fed from the floor above)
  6. As long as this is not a combination boiler then check near the cylinder to make sure there is no air valves which you may also need to undo
  7. Once the system is completely drained then all air vent valves need to be tightened up
  8. Turn the mains water back on and refill the central heating
  9. Wait until central heating tank is full then start filling up radiators start with the ground floor upwards
  10. Once central heating is completely full then turn the boiler back on to warm radiators up
  11. From Answer 2 If you don’t have a drain off valve then you can either drain from boiler or follow other instruction below
  12. At the lowest radiator turn off both central heating valves (If you have a thermostatic radiator valve and the room is too cold the valve may open up to let water through)
  13. Depending on the radiator, most radiators you are able to attach a drain of valve by using PTFE to make a seal then attach a hose pipe and draining down, (go back to answer 3)

Please note: A combination boiler is completely different to the above and is also allot easier to get an airlock out, to get an airlock out of a radiator all you need to do is open up a radiator valve, always make sure you have plenty of water pressure in your central heating and open one valve at a time well getting an airlock out.

There are always other ways to get an airlock out of a central heating by following the list below

  1. Open up radiators that have plenty of air in until you hear a bubbling effect
  2. Turn all radiator off except for one and run the central heating, (do this to every radiator in the house)
  3. Jump start the pump by using the setting from 1 to 3, to stop the pump with a count of 10 put the switch between 2 and 3 then back on to setting 3

If you are a Plumber and reading this article then be free to give us your point of view below.

As a very experience Plumber, we hope you follow these instruction in order to solve your problem , the chances of not fixing this air in water pipes issue is possibly a 1 in 10, this is our money saving tip but is not guaranteed.

If you have any further problems then please give us a call and we will get an experienced plumbing engineer to you possibly with 30 to 90 minutes if in an emergency. We operate a 24 hour plumbing service.



2 Comments so far

  1. simba on September 17, 2012 2:14 pm

    we have water problems in my area. Many a times when there isn’t water my kids left the taps on and this has been resulting in a disaster in house 4 the past years. l want to use air lock system to prevent this from happening again. For example when the tap is left open and there is no water (an airlock that would prevent water from coming out until attended to must be set up).help me come up with a mechanism.

  2. motorised valve Information, tips and includes the 2 way and the 3 way on December 11, 2012 9:35 am

    [...] the switch located on the motorised valve. This will also help you determine whether it is an Central Heating Airlock or in fact the motorised valve. [...]

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