FURNACES

Problem Solving

Furnaces

A wiring malfunction found in a heat pump was traced to corrosion damage at the location of a pass-through in the compressor housing. The increase in electrical resistance finally caused several leads to melt and prevent the unit from operating.

The following examples illustrate some of our contributions to this business sector:

  • Touchstone was contacted regarding problem that involved the failure of a cast iron steam boiler assembly. TRL concluded that the failure seen in this boiler was most probably the result of an initial failure of at least six of the internal stay bolts and a portion of the corner of the casting. The final failure would have occurred when the remaining section thickness could no longer sustain the loading on the internal surface. The presence of stay bolts indicated some understanding of the forces present during use but the overall design did not appear to allow for the rather unique properties of gray cast iron. The final report stated that the use of internally cast-in-place staybolts was inadvisable because of the mechanical properties of gray cast iron, particularly, low elongation. There was no evidence that this design had been approved by the ASME section VIII committee.
  • The examination of a short circuit in an older, high efficiency gas furnace found that the system designed to collect condensation from the exhaust had become clogged by airborne soil and insect debris. The inability to conduct condensed water properly allowed the water to corrode an electrical connection and eventually prevent the furnace from operating.
  • A wiring malfunction found in a heat pump was traced to corrosion damage at the location of a pass-through in the compressor housing. The increase in electrical resistance finally caused several leads to melt and prevent the unit from operating.

The above examples are only a sample of our work in this area. We would be pleased to provide any additional information you may require. We also invite you to review examples on our website of work that we have performed in support of other business sectors.