CarePenguin and hot water recirculation systems water heater next to woman handing CarePenguin penguin a phone

CarePenguin and Hot Water Recirculation Systems

CarePenguin works with nearly all hot water systems used worldwide whether they are tank based, boilers, or tankless systems.  This is because CarePenguin monitors the temperature of the pipe that exits the water heater.  As demand for hot water occurs the pipe exiting the hot water system will heat up rapidly and CarePenguin looks for this to signal a water use event.  

There is a case where CarePenguin will not work however: locations with residential hot water recirculation systems. These systems are generally designed into the house at build time (often requiring additional plumbing) and involve moving the water constantly from the hot water heater into the pipes, to the point of use faucets, and back to the hot water heater. This allows house occupants to always have hot water at the point of use without having to wait for hot water to reach the sink, shower etc.

hand pointing at recirculation pump on water heater
This is what a recirculation pump looks like

These systems are generally rare, but in some locations of the country such as California, larger houses built since 1980 are required to have such a system. The reasoning is that waiting for hot water is a waste because users run water down the drain waiting for the hot water to reach them and the conservation of water is more important than the conservation of energy in these municipalities.

While hot water recirculation systems are nice, they can use significant energy and can be costly to operate unless they are tuned to the user’s behavior patterns.  These systems by design are heating water in uninsulated pipes for most or all of the day.

Recirculation systems are not compatible with CarePenguin, however, because they keep the water in uninsulated pipes in the house close to the temperature of the water in the insulated water heater. As a result, CarePenguin cannot determine water use events because the pipe never cools down.

Some people turn off their recirculation systems due to power usage and in those cases CarePenguin would work as designed.

An easy test to see if your house has a hot water recirculation system is to turn the faucet or shower on HOT first thing in the morning.  

  1. If it takes 45-90 seconds or more before hot water comes out of the fixture you DO NOT have a recirculation system and CarePenguin WILL work for you.  
  2. If hot water from the tap is instantly hot first thing in the morning, then you likely DO HAVE a recirculation system and CarePenguin IS NOT compatible with that location unless the recirculation system is shut off.

Here is a great resource on hot water recirculation systems.