In this video, This Old House plumbing and heating expert Richard Trethewey makes heating water more efficient by installing a heat pump. Read on to see the steps for this water heater heat pump retrofit.
Steps for adding a heat pump to a water heater
- Shut off the cold-water line and electrical circuit to the water heater.
- Pump all the water out of the water heater’s tank.
- Open a hot-water faucet in the kitchen to release pressure and break the vacuum in the tank.
- Use a pipe wrench to remove the drain valve from the water heater.
- Replace the old drain valve with a single-entry valve. Wrap plumber’s tape around the female threads and tighten the new valve into the drain-valve hole.
- Attach two lengths of PEX flexible tubing to connect the heat pump to the single-entry valve on the water heater.
- Slip foam-rubber pipe insulation over each length of PEX tubing.
- Drill a ½-inch-diameter hole through the thermostat cover on the water heater, then attach a rubber strain-release fitting.
- Feed an electrical cable from the heat pump through the strain-release fitting and attach it to the thermostat on the water heater.
- Screw the thermostat cover back onto the water heater.
- Install a condensate pump to collect and discharge condensation from the heat pump to the washing machine drainpipe.
- Turn on the cold-water line and the electrical circuit.
- Fill the water heater’s tank with water.
- Turn on the heat pump.