If you need to install or repair pipes or fixtures, you'll want to hire a plumber. If you need to install or repair a heating system, you'll want to hire a heating engineer.

Plumbers typically work on heating systems, including radiators and pipework, but not all of them are qualified to work on the boiler itself or the gas pipe. However, these days you'll find that some plumbers have also trained as Gas Safe engineers – making them well-equipped to repair a gas boiler.