Snipps warns Western Slope homeowners about furnace altitude adjustments

Snipps Heating & Air Conditioning is urging Western Slope homeowners to verify furnace derating and high-altitude setup before winter weather intensifies in the mountain towns. The company says a furnace that works at valley elevations can be unsafe or underpowered higher up if it is not adjusted for thinner air.

Why it matters: - Elevation changes how gas and cooling equipment performs across the Western Slope. - A furnace sized and installed for valley elevations can be unsafe, inefficient or underpowered in mountain communities above 9,000 feet. - Winter arrives earlier in the mountain towns than in Montrose and the valley, so the timing for inspection is now.

What happened: - Snipps Heating & Air Conditioning is telling homeowners to confirm their heating equipment was adjusted for elevation before the season sets in. - The company has served the region since 1996 and covers communities from roughly 5,000 feet in the valley to more than 9,000 feet in the mountains. - Snipps says elevation is the most misunderstood factor in heating equipment on the Western Slope.

The details: - Gas appliances are rated at sea level. - Under the National Fuel Gas Code, those ratings stay unchanged up to 2,000 feet. - Above 2,000 feet, input must be reduced by 4% for every 1,000 feet of elevation. - Equipment should be selected using the corrected figure, not the nameplate rating. - A 100,000 BTU furnace installed at about 6,000 feet operates with roughly 16% less capacity than the label suggests. - Thinner air carries less oxygen, and gas appliances need oxygen for clean combustion. - High-altitude kits change the orifices and input rate to correct the air-to-fuel ratio. - Derating helps stabilize the flame, protect the heat exchanger and keep the fuel-to-air ratio in a safe range. - Skipping derating can lead to incomplete combustion, elevated carbon monoxide, nuisance lockouts and overheating. - Trade reporting has identified incorrect or missing elevation derate work as one of the most common errors seen by Colorado distributors. - Manufacturer installation manuals place responsibility for input adjustment on the installer. - Many manufacturers say their equipment is not approved above a set elevation, often 8,000 or 10,000 feet. - Installing above that threshold can void the warranty and fail inspection. - Propane requires separate handling because natural gas derating tables do not transfer to LP equipment. - Cooling equipment is affected at altitude as well, because fans move less air and heat transfer slows.

Between the lines: - The issue is partly a safety problem and partly a performance problem. - Homeowners may think they bought enough furnace for their home, but altitude can reduce usable output enough to leave the system undersized on the coldest nights. - The company’s warning also reflects a practical service reality: many mountain homes are already heating before the valley floor needs regular heat.

What's next: - Snipps recommends homeowners ask whether an altitude derate was performed. - Homeowners should also ask whether a high-altitude kit was installed and whether a combustion test was run and documented at commissioning. - If those answers are unclear, Snipps says the system should be inspected before winter demand peaks. - Snipps offers 24-hour emergency HVAC service at 24-hour emergency HVAC service or by calling (970) 240-8152.

The bottom line: - In mountain towns, the same furnace is not the same furnace. Altitude changes combustion, capacity and safety, so installation details matter as much as the equipment label.