The only test that I am aware of is to use a mighty vac hand pump (or similar tool) to apply vacuum to the check valve and ensure it holds a vacuum for up to 3 minutes (no leakage). While this is an important test, it is not the only indicator whether or not the booster works. Mine tested fine, but failed to work. When I returned the unit, they said the insides were a mess and no wonder it was not working.