How do you find out where you have water leak

Hi Edith_92, it is highly likely that your leak will be on one of your radiators. Although this is the likely place where the leak is, it is not 100% definite as it is possible to be on a hidden heating pipe in the floor etc.. This leak will be a small leak that may only show when the heating is off. However it may also only show when the heating is on. Therefore firstly you should run your fingers around all of the silver coloured nuts and the copper pipes as they enter each side of every radiator… As stated, this should be done when the radiators are cold and if no leak found then check again when the radiators are hot. If your fingers get wet then you have found the leak. Also check the top of the radiators. At the very top of each radiator and at one end only, there will be a small square nipple. This is where the radiators are bled from with a special key to remove any air from the radiators. You should also check each radiator at that point as this is a potential area for a minor leak. Also a helpful tip is to feel the carpet (or look at any hard floor) under the radiators to see if you can feel or see a wet patch near to the radiator pipes. Even the smallest drop of water or minor water stain could be the clue to where your leak is coming from. It is possible the leak could be small enough to dry up and not always show the presence of water so check thoroughly. If after all these basic checks you do not find the leak then you could try wrapping tissue paper around the silver nuts mentioned above and check the tissue after a day to see if the tissue shows any signs of water ingress. Failing all of the above you will need to call a plumber to resolve. I hope this helps. Good luck, Ken

I recently came across a problem like this no sign of leaks but water pressure keeps dropping no matter how many times you top it up, I found the leak eventually by tieing a balloon around the blow off outside, the next day the balloon had filled with water, the blow off valve was passing water I changed it and the problem went away

The previous two answers were what I thought, good answers. If it's neither of these it could be a leak from pipework under ground floor floorboards. Which would become. A bigger job. A heating engineer could put some sealant into the system first to see if that cures the pressure dropping as it may seal a small leak.