HVAC Frequently Asked Questions

Once a year, ideally in early autumn before the first hard freeze. Minnesota furnaces run far more hours per season than furnaces in milder states, so an annual tune-up catches worn ignitors, cracked heat exchangers, and failing blower motors before they leave you without heat in January. If you have pets, run a humidifier, or the unit is more than 10 years old, it is worth booking that visit every year without fail.

A frozen coil almost always means airflow or refrigerant. The most common cause is a clogged air filter starving the evaporator coil of warm return air. Blocked supply vents, a dirty coil, or a failing blower do the same thing. Low refrigerant from a leak will also drop coil temperature below freezing. Turn the system to fan-only to thaw it, replace the filter, and if it refreezes, call us — running a frozen system can damage the compressor.

At 20 years a furnace is past its typical 15–20 year service life, so the honest answer depends on the specific repair. Our Service Priority Promise means we will do everything we can to keep your existing unit running safely first. That said, if the repair approaches a large share of replacement cost, or if we find a cracked heat exchanger — a safety issue — replacement is the better use of your money. We will lay out both options with real numbers and let you decide.

Sizing should come from a Manual J load calculation, not a rule of thumb. It accounts for your square footage, insulation levels, window area and quality, air sealing, ceiling heights, and orientation. Oversizing is a real problem, not a safety margin — an oversized furnace short-cycles, wears out faster, and leaves uneven temperatures between rooms. We run the calculation as part of any replacement quote.

Check the thermostat fan setting first: if it is on ON rather than AUTO, the blower runs continuously and pushes room-temperature air between heating cycles. Beyond that, cold air can mean a failed ignitor or flame sensor, a tripped high-limit switch from a dirty filter, a condensate blockage on a high-efficiency unit, or an interrupted gas supply. If the burners are lighting and then cutting out, stop running the system and give us a call.

A standard 1-inch filter should be changed every 1–3 months; thicker 4- or 5-inch media filters typically last 6–12 months. Shorten that interval if you have pets, allergies, or ongoing construction dust. During deep winter and peak summer, when the system runs nearly constantly, check it monthly — a clogged filter is the single most common cause of the service calls we get.

During a stretch of subzero weather, continuous running is often normal — the furnace is correctly sized for design conditions, not for -25°F, so it simply cannot get ahead. Worth checking anyway: a filter that needs changing, leaky or uninsulated ductwork in an unconditioned space, and air sealing around rim joists and windows. If the house still will not reach the setpoint in ordinary winter weather, that is a real problem and we should look at it.

Increasingly, yes. Modern cold-climate heat pumps hold useful efficiency well below 0°F, and the usual Minnesota setup is a dual-fuel system: the heat pump handles the shoulder seasons and moderate winter days, and a gas furnace takes over at the coldest temperatures. Whether it pencils out for your home depends on your electric and gas rates, your existing equipment, and available rebates. We are happy to walk through the math with you.

It varies widely based on system size, efficiency rating, whether ductwork or the electrical service needs modification, and the condition of your existing lineset and pad. Rather than quote you a number that may not reflect your home, we will come out, assess the actual installation, and give you a written upfront price with no hidden fees. Financing through Wells Fargo is available with approved credit, and we always provide a free second opinion on quotes from other contractors.

Replace the furnace filter, vacuum around the unit, and confirm supply and return vents are not blocked by furniture or rugs. Outside, clear leaves and snow away from high-efficiency intake and exhaust PVC pipes — a blocked intake will shut the furnace down. Test your carbon monoxide detectors and replace their batteries. Then book a professional tune-up so a technician can check combustion, safety controls, and the heat exchanger before the cold arrives.