How long hose?

IanH

We have a Weber Baby Q BBQ and to save buying those expensive little gas cannisters, I've just bought a 3m length of hose and the fittings to plug into the gas outlet on the side of the caravan.

Just been to try it out and it won't work - no gas is getting through. In fact, I could not smell gas at all, even when I unplugged the hose from the caravan outlet and sniffed the hose.

I reconnected a little gas cannister and it lit first time.

Is there a limit to the length of hose that you can use or do you think there's something wrong with the gas supply? (The cooker in the caravan works fine).