Serving Monterey Park, from the Highlands to Ramona AcresText a photo: (310) 628-9399

Recirculating pump controls compared

A recirculating pump brings hot water to far taps faster.

Call nowText a photo

Six days a week · all of Monterey Park

Call or text

(310) 628-9399

Mon–Sat, 8:30 AM–7 PM

Updated · 3 min read

Bottom line

A recirculating pump moves hot water through the pipes so it arrives at far fixtures sooner. Timer controls run it on a schedule, thermostat controls run it when the pipe cools, and on-demand controls run it only when someone presses a button or a sensor triggers.

Contents
  1. Why recirculation helps
  2. Dedicated loop or crossover
  3. Choosing the control
  4. What installation involves
  5. Before you call

Why recirculation helps

In a long single-story ranch or a split-level house in the hills above Atlantic Boulevard, the master bath may be far from the water heater. Cold water sitting in that line goes down the drain before hot arrives.

A pump returns that cooled water to the heater instead of the drain.

Heater sends hot water then Water cools in the line then Pump pulls it back then Hot water waits at the tap1Heater sends hot water2Water cools in the line3Pump pulls it back4Hot water waits at the tap
How a recirculating loop works.

Dedicated loop or crossover

Some houses have a dedicated return pipe from the farthest fixture. Most older homes in Monterey Park, where the median house dates from 1963, do not.

Those homes use a crossover valve under the farthest sink, which sends cooled water back through the cold line.

Dedicated return line: Separate pipe back to heater; Cold line stays cold; Common in newer builds. Crossover valve: Uses the cold line to return; No new pipe needed; Cold tap runs lukewarm brieflyDedicated return line• Separate pipe back to heater• Cold line stays cold• Common in newer buildsCrossover valve• Uses the cold line to return• No new pipe needed• Cold tap runs lukewarm briefly
Two ways to complete the loop.

Choosing the control

  • Timer: runs during set morning and evening windows. Simple, but runs whether or not anyone needs hot water.
  • Thermostat: runs when the pipe cools below a setpoint. Keeps water ready all day.
  • On-demand: runs only when triggered by a button, motion sensor or app. Uses the least energy.

What installation involves

Most under-sink or at-heater pumps need a nearby outlet. The pump mounts at the heater outlet or under the farthest sink, and a crossover valve or return line completes the loop.

We purge air from the lines, set the control, and check that hot water reaches the far tap and the cold side behaves.

Before you call

Will a pump waste energy?

A pump running all day loses heat through the pipes. Timer and on-demand controls keep that in check.

Can a recirculating pump work with a tankless heater?

Yes, with a compatible unit. Some tankless models have a built-in pump and recirculation mode.

Why is my cold water warm after adding a pump?

That is a crossover system returning water through the cold line. It clears after a few seconds of running.

Cited sources