There is a lot of talk these days about heat pump water heaters being the most environmentally friendly and efficient water heaters available. However, owners have reported issues when using heat pump water heaters in conjunction with a dedicated recirculation loop.
The issue is that running a recirculation pump causes radiant heat loss from the water as it recirculates through the loop. Heat pump water heaters have a very low power heating element in their storage tank to maintain the heat in the tank, but they are not powerful enough to keep up with these radiant heat losses. So if the recirculation pump runs all the time, the tank cools off until the unit hits is low temp set point and then it turns the heat pump on to heat the system back up. If you are running in Energy Saver mode this temperature is very low and you end up with luke warm water.
You can read about this in the Rheem technical bulletin. Rheem recommends only using the unit in High Demand mode or Electric only mode and says that Energy Saver mode won’t work well.
Fortunately, the Smart Recirculation Control 32 solves this problem for owners’ of heat pump water heaters as our control only turns the pump on when hot water is demanded and off when the loop is up to temperature minimizing radiant losses and preventing the heat pump water heater from cooling off thus restoring peak efficiency of your water heater investment while still providing you with the convenience of hot water at your fixtures.
Even if you don’t have a dedicated recirculation loop you can take advantage of on demand hot water with our Smart Thermostatic Control 32 Complete System. This system uses thermostatic cross over valves installed underneath the sink(s) at the furthest location(s) from the water heater and allows cold water in the hot water line to be recirculated using the cold water supply as the return line.
See what customers say about using the Smart Recirculation Control 32 with Rheem and heat pump water heaters: