Fixing a blocked water pipe caused by trapped air
It's very frustrating to open your taps and not get any water out of it. Now unless it's the draught season and the water authority board has decided to cut off water supply at specific times during the day, there must definitely be a problem with your water system. In most cases, if water is not coming out of your taps, it's because of an airlock. It happens when an air bubble gets trapped inside your water pipes and then creates a blockage, preventing water from flowing properly in your water system.
You can try some DIY tricks to fix the airlock in your house.
Step 1: Attach a hosepipe to the affected tap (tap where you're not getting any water) and attach the other end to another tap which is working fine (use a tap where there is direct feed from the mains water).
Step 2: Open both taps to allow the pressure from the working tap to force the air back out of the pipes. Leave to run for a few minutes.
Step 3: Turn off the air locked tap first and then the other one.
You may need to repeat this procedure a few times to get rid of the air lock.
If that doesn't solve the problem, then you can try to drain the water system down. You will need to turn off the water feed to your house. Locate the stopcock and turn it off. Then open all taps until all water has been drained down. After that, you need to open each tap only a little bit, let the water flow for a bit, then turn it a little bit more. Keep on opening each tap a little bit more until they are all fully open.
If you're still having problems with the airlock, then you can hire an air compressor to force the air bubble out. After plugging in the air pump, you need to put its hose to the affected tap and let air push the water back to your cold water tank. You will hear bubbles at the water tank to let you know that everything is being pushed back. After 5 minutes, you can disconnect the hose from the air compressor and you should see water flowing back from the tap.
As a last resort and if everything else above does not work, then you will need to call in a plumber. It can cost you on average £90 for a plumber to fix your air lock, so try the above methods before you call one.