Q: Why did my furnace finally bite the dust?
A: Because it was old and worn out. That initial response is certainly true but doesn’t quite answer the real question of HOW it happened. Age and general condition do factor in with an emphasis on general condition. We have seen many 50-year-old furnaces that look nearly like new and other 5-year-old units that look like they are ready for the scrap heap. Those clean geriatric furnaces are always annually cleaned and checked as well as kind of revered as they stand tall and proud in a downtown Kalispell basement. Those other, much younger furnaces still have the original (quite clogged) filters or no filters at all. Years of no attention at all will wear down even the best furnace or heat pump. Equipment located in crawl spaces don’t fare as well because of the “out of sight, out of mind” mentality. That is why we have regular (annual) service agreements and contracts that are very reasonable, and we keep tabs on the comings and goings of this big investment in your comfort and safety. Any piece of mechanical equipment, whether it be a furnace, heat pump, or boiler holds clues to its demise if one cares to investigate. “Furnace forensics” are slightly different than what the police and detectives employ fighting crime; however a few of the same skills are required. Casual observation helps and as Monk made famous in his detective TV series, the slightest deviation from the norm is a thread to go on. Thankfully, furnaces are easier to read than a messy crime scene, and there is no blood involved (save for the regular sheet metal cuts or critters in the inducer motor). A furnace we removed this week was discovered to have very elevated levels of carbon monoxide (CO) in the exhaust vent (2,000 parts per million). There are many heating companies that do not check for CO in the exhaust vent despite the manufacturer’s recommendations to do so. Every AirWorks technician performs this test during regular maintenance and during the diagnostic process of repairing any gas-fired appliance. This can only be done using an expensive tool that requires regular costly re-calibration. In this case the furnace was running OK; we were simply conducting a routine fall maintenance when we discovered the high CO levels which can be a real life-threatening situation. Remember CO is odorless, colorless and lethal. So, what caused this elevated CO? The answer comes down to a single tiny clue revealed to the surprise of everyone in the room. Quietly picked-up on the ducting below the furnace was a tiny rusted metal ring, much like a washer. Most would have tossed it away and with it, the answer. This ring and several more of them still connected, hold the halves of the steel heat exchangers together. When missing, a gap opens causing the exhaust gas to skyrocket from a normal 25 parts per million to 2,000 and higher. A breach in the heat exchanger can happen in many ways. Sometimes they simply rust through or form small fissures and cracks from millions of on/ off cycles; metal heating and cooling, expanding and contracting. This is exactly why we invest in these expensive combustion test tools and use them on every service call. It can be very difficult to visually examine a heat exchanger so a combustion test is the surest way to confirm its integrity. Combustion testing provides a wealth of information that can inform our technicians on slight adjustments that can be made to get your equipment operating at designed efficiency. Safety and efficiency are our top concerns and validate our investment in well-trained and -equipped technicians. Have one of expert techs check your system by calling today.
