Dear 3Greens,
Any descriptive of the Anti-ice systems (on most jet engines) claims to work, also at idle power, but that is mostly to comply with the certification, not in the real world.
P & W send at notice to: "All costumers" in the year 1994, that you need more than idle power to have any/some effect from the anti-ice systems.
Oluf (read all about it here:
www.whistleblowers.dk )