The Evotherm H5RO-I and H5RO-S Heat Pump Controllers regulate the pool filtration and circulation pump operation whenever the heat pump or the chlorinator needs it.
In a typical pool, the filtration pump and chlorinator run for a few hours a day following a timer schedule.To maintain the water at the desired temperature, it is possible the heat pump would need to run outside of this schedule. In this scenario, the circulation pump needs to run without the chlorinator working to avoid over-chlorination. The H5RO-I is designed for this scenario, where the circulation system includes both chlorinator and heat pump demands.
The H5RO-S is intended for stand-alone plumbing installations for separately circulated heat pumps.