Heuchera is slug resistant and has relatively few pests.
They do get attacked by leaf spots, powdery mildew, strawberry root weevil or black vine, mealybug, foliar nematode.
When mealybugs attack the base and stems, forcefully wash plants with water and mild detergent or insecticidal soap regularly.
Weevil larvae initial start feeding on smaller roots but move to the large roots or the base of the crown as the mature.
The brown or black adults emerge in late May to early June can be treated with an insecticide that has some residual activity such as acephate.
In fall, beneficial nematodes can be applied to the soil around the plants to help control weevil larvae.
Reference: https://ipm.missouri.edu