A plumber is a person who installs, repairs and maintains plumbing fixtures or systems in businesses, industries or residences. Finding a leak may seem like finding a needle in a haystack, but it’s worth a shot, before calling a heating tech most all hvac companies charge an hourly rate, which can become quite expensive, if they spend hours troubleshooting your system. Sign up to which? legal for clear, step-by-step advice on problems big and small. Generally.