Emailed Jetboil they are doing free for USA but they gave me the addy to email for us lucky UK pple.
Have pasted the whole response so that everyone knows what the answer to our problem is
Thanks for your email. You have two possible courses of action, either return it to your retailer, or direct to ourselves. Please note that we are unable to dispatch replacement stoves to anything but a UK address.
The normal course of action is to return your Jetboil to the shop you purchased it from for inspection and any required corrective action. This is because your retailer will replace it, or forward it onto us at their expense. If this is not possible, you can return the product to direct to Lyon Equipment. This will be carried out as a gesture of goodwill as the product has not been directly purchased from Lyon, and also means that we can not refund your postage.
If you choose to send it direct to us, please use the following address;
Lyon Customer Services
Clock Garage Industrial Estate
Tebay
Penrith
Cumbria
CA10 3SS
Please include your name and address and daytime delivery address for return.
Hope this helps and i'm so glad that a BFPO number counts as UK address (or does it)