DT Swiss Carbon Wheels Drain Hole – Air leaking out!

Just put on a tyre and rimpact. Everytime I pump the tyre up all the air releases through the drain hole?
what to do???

is the tape damaged

It’s just finding the path of least resistance so yes likely a tape or valve issue

Rim tape or valve.

Probably caught the tape as you were putting the rimpact in, easily done.

Tighten up the rim pact Valve stem with a pair of pliers

I had this on some carbon wheels.

The front was fine with gorilla tape. The rear took 6 attempts to stop the air coming out the drain hole.

Using Tesla tape and wider gromits on the valve sorted it for me.