Heater Tap

[Stugdum]

G'day all,
I just need to confirm whether the heater tap defaults to the open or closed position when there is no vacuum? I would have thought it defaulted to the closed position, but I thought I remembered someone mentioning in a previous thread that it defaults to the open position. Please I need an answer from someone that knows definitely one way or the other, not more uncertainty and speculation, I can do that myself! Thanks.

Stugdum

[aceventura]

The tap is open with no vacuum