Hi @markgehlks,
A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.
I suspect the issue is because you have an old gas bottle.
You might like to check out the following video for some guidance: New and improved connection valve on SWAP'N'GO gas bottles!
To summarise, the standards for gas bottles changed around 4 years ago to improve usability and safety. The main difference is that the new gas bottles have a shut-off valve that won't allow gas to be expelled without a hose connected. The new gas bottles are backward-compatible; however, the hoses that are now supplied with BBQs and gas cookers are not backward-compatible. This is to encourage purchasers of new BBQs to move over to the safer, newer style gas bottles.
Unfortunately, you will have to swap your gas bottle for a new one. If you have an old Swap-n-Go bottle, we can swap it over for a new one in store.
Let me know if you have any further questions.
Jacob
