Same thing happened to me today even the same rooster in the background,I wonder if it’s one of those ‘office workers’ that get to work from home during this pandemic so that could explain the rooster? Still a scammer tho!

Wanting details of hot water system and wanted to come around and look at it... scammers

I answered the call and they immediately hanged up

Keeps phoning my number. I've blocked it as an annoying scammer.

Went to my answering machine. Didn't leave a message, but I heard a rooster in the background.

Caller: no idea

Sounds like a room full of chatty people, They're offering a replacement hot water heater at no charge, together with a 5 year guarantee. All you need to provide, is your ID, rate notice and a current refund tax notice.
Very, very dodgy.

Scam

probably a scam - having read the other comments, I've blocked this caller

I rang back the number (03) 8488 7317, spoke with someone who hung up right away