Now you can see right away by my lack of technical expressions that … So if I ignite one of three gas-ding-bum cookers with the gas tap pressed in, then it just ignites, i.e., the flame is there. As soon as I turn up or not, at least as soon as I let the gas tap out of the pressed position, the flame goes out again. With the other two it works perfectly, i.e., the flame remains. What can that be?