hi tosh read in prev topic . u give out some good info on backpack .i bought mine over a yr ago .very little use on 4 th time i used it red light stayed on would nt work .contacted cleantech .they said flat batt .they said batt chargers supplied with kit were faulty so i bouht diff batt charger off cleantech .charged batt 24 hrs again .still same prob. so they sent me new push button unit this worked 3 times then same prob .i tested wires inbetween circuit board n pump power getting that far .so could it b pump .or would damp conditions affect it .i keep it in garage . help much appreciated thanks tacky in south wales