Causes of High Winter Utility Bills
- Central heating Central heating thermostat setting is too high. thermostat setting is too high. The rule for thermostat settings in winter is: The lower the better. 68┬║ F is recommended. Lower the thermostat overnight (to 65┬║ F if you have a heat pump, or to 55┬║ F if you have gas, oil, or electric strip heating). Dress warmly. If you heat your house to 75┬║ F, expect high bills.
- Central heating system Central heating system duct leaks and duct breaks.
Leaks in the supply-air ducts push warm air into the attic or into the crawl space under the house. Leaks in return ducts draw in cold air from the attic or crawl space. Major duct leaks and disconnections can double your heating costs.
- Clogged filters, overly thick filters, two filters, clogged coils, clogged filters and restricted airflow. Airflow restrictions reduce equipment operating efficiency, which causes higher operating costs and can lead to other equipment problems. Having a second filter can be a real problem, especially if only one filter gets replaced while the other is tucked away out of sight in the air handler, clogged shut with years of dust.
- The home is heated with 10,000 or 15,000 or even 20,000 watts of central electric resistance or "strip" heat. What is strip heat? Picture a super-sized glowing red toaster element that warms the passing air in your central ductwork. "Strip heating" systems are cheap to install but costly to operate. Winter after winter, this is the most common cause of acute high electric bills in Tallahassee. The strip-heat operating costs, based on November 2010 utility rates and applicable taxes, are as follows:
- 10,000 watts, typical in smaller apartments: $1.30 per hour (nonstop operation).
- 15,000 watts, typical in larger apartments, homes to about 1,500 square feet, and many mobile homes: $1.95 per hour (nonstop operation).
- 20,000 watts, found in some larger apartments, some homes from 1,000 to 2,000 square feet, and some mobile homes: $2.50 per hour (nonstop operation).
- Heat pump Heat pump thermostat accidentally set to Emergency Heat. A common finding, and it can be a costly mistake that leads to higher winter bills. Set on Emergency Heat, the energy efficient heat pump isn't enabled Γ?? Only its 10,000 or 15,000 watts of backup heat strips are on. Operating cost doubles.
- Heat pump stuck in defrost mode. The system heats and cools simultaneously, heating with backup strips. Operating cost triples.
- Heat pump thermostat wired incorrectly. When set to "HEAT", it cools at first, then heats with both the heat pump and its backup strips. Or it heats-and-cools simultaneously, heating with backup strips. Sometimes happens when a new heat pump is mismatched to an old thermostat. Operating cost doubles or triples.
- Heat pump configured or wired so that backup strips operate during every heating cycle; or the heat pump has an incompatible thermostat. Similar to above cause, but in this case whenever the heat pump operates, its backup strips operate as well. The customer feels warm, but at twice-the-normal operating cost.
- Heat pump condenser failed or locked out. The outdoor fan doesn't spin. The primary energy-efficient heat pump isn't functioning. Only the backup strips are operating. Operating cost doubles. A common finding. Uncorrected, it can create high bills all winter.
- Heat pump condenser circuit shut off at the breaker panel. The outdoor fan doesn't spin; only the backup strips are operating. Operating cost doubles. If undetected, it can cause high electric consumption and high bills all winter.
- Heat pump defrost controls are faulty. The unit switches to defrost mode every five minutes or so. It shouldn't defrost so often. While in defrost mode it heatsand-cools simultaneously, heating with expensive backup strips, at triple the usual operating cost.
- Heat pump low on Heat pump low on refrigerant or has too much refrigerant. Either too much or too little is a problem. The system runs longer to provide adequate heat, and costly electric strips come on more frequently. Operating costs can double.
- Heat pump backup electric strips operate silently On/Off, even when the thermostat is set to "OFF." Several causes were found, including accidental metal-tostrip connections in the air handler - for example, electrical connection made in the ar handler by a peel of metal foil off the duct insulation. This can also occur in 10,000- to 20,000-watt central electric strip heating systems that are not heat pumps, and results in an astonishingly high electric bill. While uncommon, it can be alarming when it happens.
- Heat pump tripped its pressure / temperature high-limit switch, so that only the backup electric strips are used. Operating costs can double. This is not a concern with most newer heat pumps. Various causes including dirty filter, clogged evaporator coils behind the filter, and refrigerant over-charging. The problem may begin at the first Fall defrost cycle and continue all winter undetected.
- Two-story house with two heat pumps: The upstairs heat pump fails and now the downstairs one works twice as hard pump fails and now the downstairs one works twice as hard in winter. The downstairs working heat pump will try to maintain the
temperature selected at its downstairs thermostat. Because the system is too small to heat the entire house on colder days, it activates its backup heat strips sooner, and strips operate longer. Operating costs can almost double.
- The gas furnace has a poor flame adjustment. There is too much or too little primary air (the air pre-mixed with gas prior to combustion). Operating cost increases.
- Gas furnace with insufficient secondary air. The furnace operates at lower efficiency if there is too little secondary air (air supplied to the burner flame at the moment of combustion).
- Gas furnace is short-cycling. The furnace operates in short, inefficient bursts. This can be caused by equipment oversizing, or sometimes by problems with thermostat location. Increased operating cost.
- Multiple plug-in space heaters. For about 20 cents per hour, a single plug-in, 1,500-watt electric space heater heats a room quickly and effectively if you close the door to keep the heat from escaping to the rest of the house. The hourly cost seems low, but it can add up, especially where multiple heaters are used to heat the entire house. Use plug-in electric heaters cautiously.