Heating System Repair

Heating problems tend to show up at the worst possible time, usually during the first real cold snap of the season when your system has been idle for months. The most common symptom is a complete lack of heat, where the thermostat calls for heat but nothing happens. This can indicate an ignition failure in a gas furnace, a tripped safety switch, or a thermostat wiring issue. If your heating system runs but produces lukewarm air, you may be dealing with a failing heat exchanger, a bad gas valve, or a heat pump that is stuck in defrost mode. Unusual smells are a serious warning sign. A rotten egg or sulfur smell near a gas furnace means a possible gas leak.

Turn off the furnace, leave the house, and call your gas company immediately before calling for repair. A burning smell when the heat first turns on is usually dust burning off the heat exchanger and is normal, but a persistent electrical burning smell indicates an overheating motor or wiring issue. Frequent cycling, where the furnace starts and stops repeatedly, often points to a dirty flame sensor, a faulty pressure switch, or an oversized system. Strange banging noises from a furnace can indicate delayed ignition, where gas builds up before igniting, which is both an efficiency issue and a potential safety hazard.

Heat pumps are increasingly popular in Nashville because they provide both heating and cooling from a single system. However, they have unique repair needs during heating season. The reversing valve, which switches the system between heating and cooling modes, can fail or stick. A stuck reversing valve means your heat pump may cool when it should heat. Defrost cycle problems are common in Nashville winters. Heat pumps extract heat from outdoor air, and when outdoor temperatures drop near freezing, ice can form on the outdoor coil. The defrost cycle is designed to periodically melt this ice, but when the defrost control board, defrost thermostat, or reversing valve malfunctions, ice builds up and the system loses heating capacity.

Low refrigerant charge affects heating performance just as much as cooling performance. In heating mode, a heat pump absorbs heat from the outdoor air, so proper refrigerant charge is critical. Auxiliary heat strip failures leave you without backup heat during the coldest weather when the heat pump alone cannot keep up with heating demand.

Gas furnaces have an average lifespan of 15 to 20 years, while heat pumps typically last 12 to 15 years. If your heating system is approaching or past these benchmarks and requires a major repair, replacement deserves serious consideration. Safety is another factor. A furnace with a cracked heat exchanger should be replaced rather than repaired because the risk of carbon monoxide exposure is too significant. Similarly, furnaces with repeated ignition failures or gas valve issues may pose safety risks that justify replacement. Energy efficiency improvements in modern heating systems are substantial.

A new high-efficiency gas furnace with 96 to 98 percent AFUE rating uses significantly less fuel than an older 80 percent efficiency model. For heat pumps, newer systems with higher HSPF2 ratings and variable-speed compressors deliver more consistent heat while using less electricity. We will always give you an honest assessment and help you weigh the cost of repair against the benefits of a new system.