How to Create Zones in a Hot Water Heating System

In this how-to video, This Old House plumbing and heating contractor Richard Trethewey shows how to share the warmth by installing zone valves.

In this video, This Old House plumbing and heating contractor Richard Trethewey explains how to create zones in a hot-water heating system.

Steps for Adding Zones to a Hot Water Heating System

Turn off the cold water line to the boiler; shut the electricity to the boiler.
Drain water from the boiler, if there’s no floor drain remove water with an electric pump.
Cut copper pipe coming from the boiler with a tubing cutter.
Use a reciprocating saw to cut steel pipe, and remove the remaining pipe with a pipe wrench.
Thread copper adapter into the boiler to connect new copper tubing; apply both pipe sealant and Teflon tape to threads of the adapter.
Solder together new zone valve assemblies and attach to the boiler with solder-less fittings.
Install the wireless thermostat in the room of the new zone; locate the thermostat away from direct sunlight or cold drafts, and about 60 inches above the floor.
Install an electric control box beside the boiler and make wire connections between zone valves and thermostats in each zone.
Turn on the cold water line and electricity to the boiler.