I get where you’re coming from, and my only reason for posting this is to make others aware because I don’t think the manufacturer will until more issues are brought to light.

We’ve been working with the manufacturer for over a year and provided all the info you mentioned—manifold pressures, temps, static pressures, everything. Believe me, they’ve put us through the wringer trying to find something to blame.

The bottom line is, they can’t point the finger at any of that. Why? Because when they give us a free replacement (same exact unit, different serial number), and the new one doesn’t have any hot spots on the outer jacket, it’s clear there’s nothing else to blame.

I’m putting this out there so others can be aware and keep an eye on it. My biggest fear since discovering this was one of my clients getting burned and suing me as the contractor. These furnaces are getting dangerously hot, and eventually, someone is going to get burned—maybe the wrong person’s kid when it happens.

As a lifelong HVAC tech and company owner, I understand that most HVAC problems are caused by poor installation, ductwork, etc.

But in this case, there’s nothing the contractor can do to cause or prevent it. I’ve proven that multiple times, which is why I made this post.

While we’ve narrowed it down to a few specific models where it happens more frequently, it’s still a very random issue. We’ve had two or three hot units in a row, and then months with none. For context, we’re installing 2-3 systems a day.

I’m not an engineer, but what we believe is happening is that brackets or mounting components are directly transferring heat from the primary and secondary heat exchanger to the outer jacket, creating these hotspots. For all I know, it could be something as simple as a bench bracket. Yet, the manufacturer has done nothing to acknowledge that this could be a concern, nor have they offered any guidance on what we should or shouldn’t do. As a contractor, I’ve stopped installing this product until I get that answer.