The Smart Aquastat Control 32 is an “on-demand” smart hot water recirculating pump controller for homes with a Navien combi unit and a dedicated recirculation loop. The other application is for tankless water heaters that don’t modulate flow to provide hot water at the temperature set point. If you don’t have a dedicated recirculation loop check out our Smart Thermostatic Control. 

The Smart Aquastat Control differs from the Smart Recirculation Control in that it has only a single temperature sensor and turns the pump off when the single sensor reaches the configured temperature rather than run the pump until the temperature difference between the water heater outflow and the return line are within the defined tolerance.

It is designed to sense when hot water is drawn from any plumbing fixture and to run the recirculation pump until the water in the recirculation loop reaches the programmed temperature. The microprocessor-based design monitors the temperature of the water returning in the recirculation loop to ensure the water in the loop stays hot while hot water is being used. 

Tankless water heaters are good at producing a never-ending supply of hot water however, they are only capable of increasing the temperature of the water at a certain rate. If water is pulled through them too quickly they will not product hot water at their temperature set point. Most modern tankless water heaters will modulate (reduce) the rate of flow so that the output water is at the set temperature. If your unit does modulate the flow then you can use the Smart Recirculation Control 32 which uses the temperature difference between the water coming out of the water heater and the temperature of the water returning in the recirculation loop to know when the water it hot and turn the pump off.

If your tankless water heater does not modulate the flow of hot water then you will need to use the Smart Aquastat Control 32 to prevent the pump from cycling on and off while the loop is heating up.

To operate go to any faucet and turn the hot water on, then off.  The Smart Aquastat Control senses this minimal draw checks the water temperature in the loop, and if necessary, starts the pump running.  Within seconds the water loop is hot and you are able to draw hot water. 

Because the Smart Aquastat Control uses the demand of hot water to know when to run the pump, it works even when your washing machine or dishwasher needs hot water. 

Unlike other on-demand hot water systems, there is no need to install switches or sensors at each faucet location and run wires or maintain wireless transceivers.  

The Smart Aquastat Control also has a set of Smart Timers that can be used to heat the recirculation line on a schedule. 

The Smart Controller only runs the pump until the line is heated up to the programmed temperature.  

Of course, outside of the timer periods, the controller will still run the pump on demand.

The “Smart Timers” are disabled if the controller doesn’t sense a hot water draw within 24 hours.  So if you go on vacation and forget to manually disable them, no worries, they will turn themselves off and re-enable as soon as it senses a hot water draw.  The “Smart Timers”  are set via your Android or iPhone smart device.

Leridian Dynamics also makes a LEED for Homes v4 compliant on-demand Smart Aquastat Control 32.