Hot Water Recirculation Pump Setup
Updated February 20, 2026
Tired of running the faucet for two minutes waiting for hot water? A recirculation pump keeps hot water circulating through your pipes so it's ready the instant you turn the handle. There are two types: dedicated return line systems (more efficient but require a separate pipe run) and comfort valve systems (use the cold water line as a return -- much easier to retrofit). For most existing homes, the comfort valve system is the way to go.
Overview
Tired of running the faucet for two minutes waiting for hot water? A recirculation pump keeps hot water circulating through your pipes so it's ready the instant you turn the handle. There are two types: dedicated return line systems (more efficient but require a separate pipe run) and comfort valve systems (use the cold water line as a return -- much easier to retrofit). For most existing homes, the comfort valve system is the way to go.
What to Know
Tools & Materials
- Recirculation pump kit (pump, comfort valve, timer)
- Adjustable wrench
- Thread seal tape
- Bucket and towels
Step by Step
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Mount the pump at the water heater
Install the pump on the hot water outlet of the water heater. Most kits connect inline with threaded fittings. Shut off the water heater, close the supply valve, and drain a bit of pressure by opening a hot faucet. Thread the pump onto the outlet.
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Install the comfort valve at the furthest fixture
At the fixture furthest from the water heater, install the crossover valve under the sink. It connects between the hot and cold supply lines with simple threaded fittings. The valve has a temperature-sensitive element that opens to let water circulate and closes when the water reaches the set temperature.
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Set the timer
Program the timer on the pump for the hours you typically use hot water. No need to run it at 3 AM. Morning (6-8 AM) and evening (5-9 PM) is a typical schedule.
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Plug in and test
Plug the pump into a standard outlet near the water heater. Turn the water supply back on. Open a hot faucet at the furthest fixture -- you should get hot water within 30-60 seconds instead of the usual 2-3 minutes.
Pro Tips
- The comfort valve does send slightly warm water through the cold line during circulation. It's barely noticeable but if you want ice-cold water from the cold tap during circulation hours, a dedicated return line is the better option.
- If you have a tankless water heater, check that the recirculation pump is compatible. Some tankless units have a built-in recirc function.
- Install the comfort valve at the fixture that's truly the farthest from the water heater by pipe run, not necessarily by distance -- the pipe route through the walls matters.
Mistakes to Avoid
- Installing the pump on the cold water inlet instead of the hot water outlet.
- Not setting a timer and running the pump 24/7, which wastes electricity and heater energy.
- Placing the comfort valve at the wrong fixture -- it needs to be at the end of the longest pipe run.
- Forgetting to drain pressure before disconnecting at the water heater -- hot water under pressure is dangerous.
When to Call a Pro
The comfort valve system is very DIY-friendly -- it's basically threading on two fittings and plugging in a pump. Call a pro if you want a dedicated return line installed (requires running new pipe through walls) or if your water heater connections are corroded and difficult to disconnect.
Bottom Line
A recirculation pump is a $150-$350 upgrade that saves water and eliminates the wait for hot water. The comfort valve system installs in under an hour with no new pipe. It's one of the highest satisfaction-per-dollar upgrades you can make.