Double victory .................. LPG detector, the vacuum trick didn't work so now at home, put it on the bench and gave the sensor unit a good hit with sensor cleaner, working happily now, thats a good few $$ saved while yesterday I picked up a new Holding Tank mechanism for the Thunder Can since the flap bit broke, new flap $29 but when one bit of plastic breaks with these things more are sure to follow so grabbed a whole assembly, $95 and sure enough when I strip down the old unit to salvage some parts I find a couple of screw tabs about to give way .............. carry 2 tanks and its certainly saved a few trips when one has a failure ....