I have water under my laminate flooring, quite a lot, and I think its extending through the whole of my ground floor. Could this be from a burst pipe, or my central heating, and who should I contact first?

I go with burst pipe. To check all water off and go to pressure gage on well and see if it drops or a city water meter and look for the little dial ( not just the numbers) and see if it moves If yes water line. If numbers don't move then another source check this first and post back

Signed 21 boat

If my answer helped rate this answer

Let me add a bit to boats answer. To check to see if you have a hidden leak first shut down everything in the house, no flush, no drinks of water, and if you are on a meter go out and check the little pointer in the gage. It should not move or creep. If it does you have a leak. If you're on a pump then check the pressure gage after the pump builds up to pressure and shuts off. The gage should not fall and the pump come back on. If so then you have a leak. Hope this helps and thank you for rating my reply, Tom