Carrier 58MVC120-F-10120

SaferProducts.gov consumer incident report 20171113-389B0-2147395465. Matched catalog product: Carrier 58MVC120-F-10120. Source model text: 58MV. Incident: We installed a Carrier gas furnace (Model 58MV). In March it stopped working and after 6 service calls from 2 different Carrier service companies (and a replaced fan and motherboard), we were told that the problem is with a heat exchanger that has been known to fail and possibly lead to carbon monoxide poisoning. Here is one of many articles from HVAC companies about it:

SaferProducts.gov consumer incident report 20161113-6A0ED-2147410810. Severity: Incident, No Injury. Product: Carrier 58MVC120-F-10120 (Gas Furnace). Incident: SUMMARY: our furnace firebox overheated causing air intake PVC pipe to partially burn. We are owners of a 6-year old high-efficiency Carrier furnace (model 58MVC120-F-10120) installed in the basement of our single-family home. Recently, we began smelling something abnormal in our yard and after some investigation we realized that the smell was coming from our furnace exhaust pipe. We called a local Carrier dealer for service. When the technician took off the furnace cover we found that an intake PVC pipe inside of the furnace was partially burned on the side facing firebox. The firebox has evidently overheated and whatever safety mechanism this furnace has, it failed to shut off gas supply when temperature rose to the point that the PVC pipe began to burn. We contacted Carrier directly and it referred the case to "regional distributor" who blamed the problem on improper installation (incorrect furnace pitch and piping) and asserted that there is no fire hazard, but also added that he "did not recommend" that we use the furnace. We have not used the furnace since we discovered the problem. At this point we feel very uncomfortable with Carrier representative's assertion that there is no fire hazard and in absence of a constructive remediation to the overheating problem we are probably looking at replacing our furnace with a new one. What is concerning to us in this situation is that Carrier does not appear to show any real interest to investigate this incident further for fire or other safety risk (such as possibility of someone inadvertently placing combustible materials on