There are many different recirculation pumps on the market and it can be quite confusing to know which one to choose for your recirculation system or even if the pump that you currently have installed is adequate. Because our controller is designed to run the pump only when you demand hot water, having a high flow pump is important to provide adequate responsiveness and comfort. It is for this reason that we recommend a pump that will flow 15 - 20 GPM. These are generally 1/12 HP pumps. We sell a pump that meets this criteria called the AquaMotion AM5-SF1L. This pump is rated at 18 GPM and 1/12HP and is adequate for most homes. For larger homes or homes that have a 1" recirculation loop installed or for people who just want the best on demand performance we recommend the AquaMotion AM10-SF1L. This pump is rated at 31 GPM and 1/8 HP. All AquaMotion pumps are designed and manufactured in the USA and come with a 3 year warranty. These pumps require a flange kit which is included in the price (specify 3/4" or 1" when placing your order) and they come with a 10 ft. electrical cord.
If you already have a pump installed and are wondering if it is adequate, look on the pump for the rated wattage. If it is less than 50 watts then it will probably not provide adequate on demand performance. Specifically we have come across some very small 1/40 HP (20 watt) pumps that only provide 3 - 5 GPM flow and they really don't work well in an on demand environment. A simple test you can perform would be to unplug the pump at night before you go to bed. Then, first thing in the morning before anyone uses hot water, get a timer with a second hand and plug the pump in. Hold the return line and time how long it takes for the pipe to start getting warm. Anything longer than 60 - 90 seconds will probably not provide adequate performance.