hi all,

Just thought id throw it out there,

whats the story with external water heaters being located under a deck thats having a roof built over it? polycarbonate corrugated sheeting to be exact. the front of the deck is being left open and both ends will have the same poly carb cladding on it. Owners are keen to move the appliance if it needs it.

Cant say I have come across it before and im sure its not permitted but all I can find in the code is the part regarding

Termination of a flue under a covered area or in a recess where it more or less says its ok??

(a) the covered area or recess shall be open on at least two sides and the terminal shall be
located to ensure a free flow of air across it is achieved; or

(b) in the case of a fan-assisted flue appliance only, when one side is open, the terminal
shall be within 500 mm of the opening, discharging in the direction of the opening
and there are to be no openings into the building along the wall within that distance
and the terminal shall be located to ensure that a free flow of air across it is achieved.

NOTE: These requirements do not apply to domestic gas barbecues and radiant gas heaters
designed for outdoor use. For these appliances refer to Appendix 1.


and that I must adhere to the measurement below the eaves,balconies/other projections which is (a) and in my case of 170mj/hr 300mm. Im picking condensation of the sheeting will occur as a result of the roof being installed. If It can stay i was thinking making it higher would be a good move as i have been told the deck was built after it was installed hence why its also a bit low.

If it has to move its going to be a way away from the bathroom hence why I want to make the correct decision with the best outcome for the customer.

Any advice gladly appreciated, will throw a photo up for all to see

Linkback: https://www.plumbers.nz/instantaneous-water-heaters/67/bosch-water-heater-under-covered-area/1727/

actually if the measurement given in (b) being 500mm to the opening mans the opening at what will be the front of the deck the answer is its not ok, even if moved to the back wall of house, still way over 500mm. Am I interpreting this requirement correctly. Its been a few years but im sure that under a deck is a no

I think this interpretation is correct but who knows what an auditor would have to say?

I would shift it to the end wall of the deck to the left looking at the second pic so it is exterior to the porch - hard to see what is on the other side/around that corner though - might have to line with hardies or similar for whatever portion needed for clearance to combustibles? give the polycarb some protection?