DDSTAT commercial controller


Hot water system thermostat

The DDSTAT thermostat operates by measuring the temperature of the water in the storage cylinder. If the temperature of the water is below the set point the controller will switch ON the pump(s) that circulate water from the cylinder through the gas continuous flow water heater and back to the cylinder.


  • Dual pump arrangement for duty / standby operation
  • Inbuilt system error detection, which can be connected to an external BMS system
  • Optional second probe (sensor lead lit R5409) that can be utilised to detect hoot water return temperatures from Rinnai INFINITY units

Technical Specifications




H-126 mm, W-220 mm, D-75 mm


1.2-1.5 kg

Enclosure construction

The LCD display and circuit board is housed in a durable plastic enclosure with a polycarbonate front cover

Ingress protection rating


Power supply

240 V AC, 10 A GPO

Contains relays and is rated for a maximum pump outlet of 1000 W. Single pump operating - 1000 W, dual pump operating simultaneously - 900 W each.

Supplied with

1 x 2 m mains plug
2 x 2 m cylinder and optional sensor

Available temp. set points

60-80 °C in 1 °C increments

Max. input of pump

<1 kW


1 year

Market release