A building consent is usually not required to replace or reposition a water heater connected to a controlled heat source, if it is carried out by an authorised person.
What the law says
Schedule 1 of the Building Act 2004 states the following:
The replacement of any water heater (including the repositioning of an existing water heater) if the replacement water heater is connected to, or incorporates, a controlled heat source or, if connected to or incorporating more than 1 heat source, 2 or more heat sources all of which are controlled.
Guidance on the exemption
This exemption enables an authorised person (refer to the glossary) to replace and/or reposition an existing water heater (of any type), as long as all the heat sources of the replaced or repositioned water heater are controlled. This exemption will not apply if a water heater has a heat source that is not controlled (eg a wetback connected to a solid-fuel heating appliance, or a solar thermosiphon system).
A controlled heat source has controls or devices that ensure the water temperature in the storage tank is no greater than 90°C.
Check with your council
If the proposed scope of the building work is outside the scope of this or any other exemption (eg adding solar collectors to an existing water storage heater, which has provision for solar connection and is not being replaced or repositioned), we suggest that you consider applying to the council for an exemption 2.
The council can then decide whether or not it will require a building consent. Before doing this, we recommend that you talk to the council to gauge whether or not it is prepared to exercise its discretion under exemption 2 on your project.
Any repair or maintenance of part of a water heater (which may include the replacement of a component of the water heating system) falls outside the scope of this exemption. Exemption 36 deals with repairs or maintenance of part of a water heater.
Replacing a hot water cylinder which is connected to an existing wetback falls outside this exemption (refer to exemption 37 for open-vented systems).
Examples where this exemption could apply
|Water storage heaters
|Solar water storage heaters
|Heat pump water storage heaters
|Instantaneous water heaters
Examples where building consent is required
|Adding a solar collector to an existing water storage heater (even if the existing water storage heater has provision for solar connection). A building consent is required because this exemption only covers replacement or repositioning of existing water heaters.|
|Adding a wetback (not a replacement wetback) connected to a water storage heater. A building consent is required because this exemption only covers replacement or repositioning of existing water heaters. Also the wetback is an uncontrolled heat source.|
|Adding a split heat pump (not a replacement split heat pump) to an existing water storage heater. A building consent is required because this exemption only covers replacement or repositioning of existing water heaters.|