Please stop defending waterfurnace actions. The analogy you are makeing does not ring true when you look at their corporate setup. They have listed prefered installers that leads the consumer to beleive that they are the best cause WF is reffering them. If a bad one slips through I think WF is culpable to clean up the mess they stuck the customer with.
If they changed their marketing strategy from the amway model to more common distribution methods like other widget makers, I would feel differently. In the end the customer is screwed and sees no way to resolution short of a complete tear out. Sad.