Omron E5CC - Lower Power to heating element?

[TwoThings]

I am looking to see if anyone else has this controller and knows how to lower the amount of power being sent to the heating element? I want to set my temp, but not have such a huge boil. I boil inside in my basement and have a steam condenser, but the amount of steam escaping my lid (held down by a weight on a gasket) is still quiet a bit.

Anyways, if anyone knows how to bring the power to the element down to, let's say 25% of total power, I'd appreciate it.

Thanks!