4.4 Replacement of open-vented water storage heater connected to supplementary heat exchanger

Open-vented water storage heater

This exemption enables an authorised person to replace open-vented water storage heaters associated with existing supplementary heat exchangers such as wetbacks or solar collection panels. The replacement water storage heater must be comparable and in the same position.

Please note: The below exemption comes into force from 31 August 2020. You will still need a building consent if your project starts before this date.

This exemption enables an authorised person to replace open-vented water storage heaters associated with existing supplementary heat exchangers such as wetbacks or solar collection panels. The replacement water storage heater must be comparable and in the same position.

What is exempt

  1. A home owner wants to replace an open-vented water storage heater with a comparable open-vented water storage heater in the same position, using the same pipe work and connected to solar water heating collectors.
  2. A building owner wants to replace an open-vented water storage heater with another open-vented water storage heater in the same position, using the same pipe work and connected to a solid-fuel heater wetback.
  3. A building owner wants to replace an external water storage heater with a heat pump water storage heater (eg replacing an open-vented water storage heater with another open-vented storage heater) in the same position, using the same pipe work and connected to a heat pump.

What needs consent

  1. Replacing an open-vented water storage heater with a valve-vented water storage heater. As the water-storage heaters are not comparable, a building consent will be required.
  2. Replacing and relocating an open-vented water storage heater and reconnecting it to the existing wood burner with a wetback. As the replaced water storage heater will not be fixed in the same position, a building consent is required.
  3. Replacing an open-vented water storage heater and adding a wetback where there was no wetback before.
  4. Adding a roof-mounted solar collection panel which will be connected to an existing open-vented water storage heater.

What the law says

37. Replacement of open-vented water storage heater connected to supplementary heat exchanger.

The replacement of any water-storage heater connected to a solid-fuel heater or other supplementary heat exchanger if the replacement:

(a). is a comparable open-vented water storage heater; and

(b). is fixed in the same position, and uses the same pipework, as the replaced water storage heater.

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: