I have had two backpacks and they both developed the same fault.
Hi Jason
I have had a look at your two backpack purchases - 2014 and July 2015 and they did seem to both develop similar faults to each other, but this was not the same fault as Stephen seems to be having.
The backpack purchased in 2014 developed a pump fault and we sent you out a replacement pump for this in July 2015
The backpack purchased in July 2015 developed a sticking pressure switch 11 months later and in June 2016 we replaced the pump for you.
These pumps are usually pretty robust and it is very rare to have a sticking pressure switch - I apologize that you were unfortunate to have a pump fault, twice a year apart