Before you call us
Note whether the problem affects hot water, cold water, or both. Both means the fault is before the hot water unit; hot only means it is after it. That one observation narrows the search considerably. The single most useful thing you can do before calling is find your water meter and the tap beside it. On most properties it is at the front boundary, sometimes under a hinged cover. Knowing where it is, and being able to turn it, is what stops a leak becoming a floor replacement.
