Where to escalate building complaints to?

House was handed over approx 1.5 years ago now, however a certain large building company is refusing to fix a vent on the heating exhaust vent.

It wasn't BAL 29 compliant, they modified it, heating company says WTF, Henley blames us for touching it (never did - house is under warranty, why would we mess with it? ) and now we are at a stalemate. I'm concerned about the warranty of the heating system too.

Also have an issue with the solar hot water system pouring boiling hot water out on the grass on a regular basis in summer - apparently the builder should have installed a drain.

Try consumer affairs or equivalent

Only as we are in the thick of it... I agree call Fair Trading and lodge a complaint, it costs nothing you can download the form and away you go...there are different time frames for non structural v's structural so do it ASAP as I was surprise how little time some things have

Include all relevant correspondence/ request to fix / quotes to fix / building report etc. Please don't let them get away with it because you think making a complaint is too hard - it's time consuming getting it together properly but after that it's easy.