Immersion Connection Instructions

Immersion Connection Instructions

Thermostat Information

The immersion heater is supplied with a RTS/RTS PLUS thermostat, approximately factory set to 80°C, with adjustable temperature.

To maintain safety and operation, any replacement thermostat must be of the same type.

Electrical Information

  1. This unit should be connected by a suitably qualified electrician in accordance with the latest I.E.E. regulations.
  2. Ensure the electrical supply is switched off before making any connection to the unit.
  3. The immersion heater must be wired through a double pole isolating switch with contact separation of at least 3mm in both poles.
  4. The immersion heater must be wired with a heat resistant flexible cord with a minimum T rating of "T-80" and with a minimum cross-section area of 1.5mm2.
  5. Ensure that the terminal screws are not over tightened as this could result in the terminations being broken off.

 This device must be earthed


  1. Earth connection (green & yellow) should be made firmly to the earth post (marked "E") using the terminals attachments provided.
  2. The Live Supply (brown) from the mains supply cable to the thermostat terminal marked "L”.
  3. The neutral connection (blue) from the mains supply to the thermostat terminal marked “N”.

Immersion Replacement Information

  1. Check your mains power voltage matches the voltage rating indicated on the label of the plastic terminal cover.
  2. The immersion heater screws into a (2 ¼" BSP) thread boss.
  3. The immersion heater must be fixed to the cylinder using the O ring provided. Please ensure that the unit is not over tightened into the tank boss.

If the heater is switched on when the water level is not fully covering the heating element there may be serious damage incurred to the heater, property or persons.

The appliance is not to be used by children or persons with reduced capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.

 The immersion must not be switched on without water within the calorifier Due to the possibility of buring out the elements and fire.

 Do not remove this cover whilst connected to 220-240 volt hook up or generator that is switched on.

Immersion Layout

Immersion Layout

The thermostat has a safety resettable cut out mechanism which prevents excessive temperatures.

The unit is able to disconnect both supply conductors (live and neutral) by a single initiating action. In case the normal sensing device fails the over temperature safety device will act to limit the water over temperature.

To reset the thermostat after an intervention of the safety device:

  1. Switch off the heater by isolating the power supply
  2. Allow the water in the cylinder to cool down sufficiently
  3. Remove the cover and press the button on the top of the thermostat

NB: This cut out is a safety device, if this is found to be operating frequently then we recommend to consult a qualified electrician to investigate the nature of the problem as the thermostat may need to be replaced. It may be helpful to lower the thermostat setting to avoid unnecessary cut offs.