Heat: The heating, ventilation, air conditioning and cooling system (often referred to as HVAC) is the climate control system for the structure. The goal of these systems is to keep the occupants at a comfortable level while maintaining indoor air quality, ventilation while keeping maintenance costs at a minimum. The HVAC system is usually powered by electricity and natural gas, but can also be powered by other sources such as butane, oil, propane, solar panels, or wood. The inspector will test the heating and air conditioner using the thermostat or other controls. Central air conditioners can only be tested when the exterior temperature is at least 65 degrees. A more thorough investigation of the system, including the heat (“firebox”) exchanger, should be conducted by a licensed HVAC service person every year. Failure to do so may result in carbon monoxide escaping through cracks in a heat exchanger or flue pipe, resulting in death.
Oil and Gas Fired Furnaces: Oil and gas fired forced air furnaces have a normal life of 15 to 20 years.
Heat Exchanger: The heat exchanger in a gas or oil furnace is hidden from view; some cannot be examined and its condition determined without being disassembled. Since this is not possible during a visual inspection, it is recommended that a service contract be placed on the unit and a service call made prior to settlement to check the condition of a heat exchanger.
Air Filter: Air filters should be changed once every 30 to 60 days to provide proper air circulation throughout the house. Humidifier: During a visual inspection it is not always possible to determine whether the humidifier is operating properly. It is recommended that it be serviced at the same time as the furnace, and be cleaned regularly.
Cast Iron Boiler: Cast iron hot water boilers have a normal life of 30 to 50 years. Steel Boiler: Steel hot water boilers have a normal life of 15 to 30 years.
Circulating Pump: Circulating pumps have a normal life of 10 to 15 years.
Heat Pump: This is an electric powered dual system which attracts heat from the outside air (or water) and transfers it inside the home in cool weather. In warm weather, it reverses the cycle, taking heat from indoors and transferring it outdoors. In warm weather the refrigerant is heated and pressurized as it passes through the compressor. In the condenser, heat is removed from the refrigerant by blowing outside door over the condenser fins causing a change to liquid state. It then passes through an expansion device into the evaporator coil expanding to a gas. As it does, it absorbs heat from the passing air. The resulting cool air is distributed through the home via a duct work system. In cold weather a reversing valve automatically changes the director of the flow of the refrigerant. Electrically heated homes require adequate wall and ceiling insulation, as well as thermopane windows and doors to keep electricity bills at reasonable levels. Heat pumps require a high volume of air to maintain a reasonable compression ratio at the compressor. Higher volume duct work is required to maintain a satisfactory comfort level. Outside units have a normal life of 5 to 10 years. Heat pumps need to be serviced at least once a year. Adequate air flow is more critical than with other forced air systems; the filter should be kept clean. It is not advisable to shut off supply grilles to rooms except as required to balance heat and cooling. You may have to set the thermostat 3 to 4 degrees higher than the desired temperature to compensate for system designing and be sure to keep the fan switch in the on position. Heat pumps cannot be checked on the heat cycle if the outside temperature has been over 70 degrees within the past 24 hours.
Electric Baseboard Heater: Electric baseboard heaters have a normal life of 10 to 15 years. If the home has electric baseboard heat, you should obtain copies of the homeowner’s last 12 months electric bills to ascertain your utility costs.
Steam Heater: Water is heated in the same way as a whistling tea kettle. As the water is heated to 212 degrees, it turns to steam and pressure increases within the system. The steam rises through the pipes to the radiators. On each radiator an air vent will open as air pressure builds within. When the steam reaches the vent, it closes. As the heat radiates into the room, the steam in the radiator condenses to water and returns to the boiler to be reheated. Most systems have a manual feed valve to allow for periodic addition of water. This should be done once a month to maintain the gauge water level at approximately one-half to two thirds full. The water level is determined by observing the sight glass or water gauge mounted on the boiler. All steam boilers should have a pressure relief valve and a low water cut off.
Hot Water Systems: These type of systems use a pump to circulate heated water throughout the home. When the boiler is activated by thermostat the water in the boiler is heated. When it reaches a certain temperature, the circulator pump will begin circulating water throughout the distribution system. As the heated water expands it is forced up into the expansion tank to prevent excessive pressure build- up. A pressure relief valve is required for all hot water systems. Water temperatures will range from 160 to 220 degrees F and pressure between 12 to 18 psi. Periodic maintenance should include cleaning and servicing of the burners, lubrication of circulation pumps, checking for water leaks and vacuuming of the radiators to remove dust and dirt build-up. It is best not to drain a boiler as added minerals and oxygen can have a detrimental effect on the boiler. A gas burner should be equipped with a safety device to cut off the gas flow in the event the pilot goes out. Some new boilers have a burner which utilizes electronic ignition rather than a pilot. It is suggested the pilot be left burning on gas fired units to prevent condensation and rust formation on the boiler during inactive periods, especially if the unit is in a damp area. If the unit has an oil burner, it should be cleaned annually. Soot build-up on the boiler walls restrict heat transfer. Service should include a check of the liner around the burner as this tends to deteriorate with age.
Warm Air Heating: Circulating air enters the furnace where a filter or electronic air cleaner traps dirt. The blower forces the air into the heat exchanger which contains metal passageways heated to temperatures of several hundred degrees by rising combustion gases. The air is then forced by a blower into the ducts for distribution throughout the house. A fan control switches the blower on and off and shuts the blower off if the temperature gets too high. Temperatures of the air are between 110 and 125 degrees F. It is important to make sure that thermostats are not placed in cold hallways or hot kitchens as the thermostat will provide an inaccurate reading as to the heat needs. To conserve energy, the air filter should be changed regularly. Annual maintenance includes cleaning, adjusting dampers, oiling the blower motor and fan, and adjusting pulley belts. You should check the filter monthly. Permanent filters should be cleaned often during the heating season and disposable types replaced when they become dirty. A gas burner should be equipped with a safety device to cut off the gas flow in the event the pilot goes out. Some new boilers have a burner which utilizes electronic ignition rather than a pilot. It is suggested the pilot be left burning on gas fired units to prevent condensation and rust formation on the boiler during inactive periods, especially if the unit is in a damp area. It is very important to maintain any humidifiers and air conditioning condensate drains to prevent them from overflowing or leaking onto the heat exchanger causing rust and eventually failure.
Buried Oil Tanks: There has been some concern over the years pertaining to metal buried oil tanks leaking. Tanks over 15 years old are considered elderly. If you are concerned about the possible presence of leaks, pressure and volume testing can be obtained, but may do damage to a weak tank. They are also very costly. There are also several non-invasive tests, but again they are costly, averaging approximately $400.00. It is recommended you discuss this aspect of the home with your attorney. Information may also be obtained by contacting the Division of Environmental Health Services. To keep your buried tank in good condition it is recommended you keep the tank as full as possible to reduce acidity and prevent possible chemical deterioration inside the tank from causing damage. If you wish to abandon your buried tank, you should contact your local municipality as each Town has its own regulations pertaining to the proper procedure for same.
The inspection of heating systems is limited to readily visible and accessible elements as listed herein. Elements concealed from view or not functional at the time of inspection for any reason cannot be inspected. A standard home inspection does not include a heat loss analysis, heating design or adequacy evaluation, energy efficiency assessment, installation compliance check, chimney flue inspection or draft test, solar system inspection, or buried fuel tank inspection. Furthermore, portable units and system accessories or add-on components such electronic air cleaners, humidifiers, and water treatment systems are not inspected, unless specifically indicated.
The functional check of heating systems is limited to the operation of a basic cycle or mode and excludes the evaluation of thermostatic controls, timing devices, analysis of distribution system flow or temperatures, or operation of full system features (i.e., all cycles, modes, and controls).
Testing the Air Conditioning System: If the outside temperature has not been at least 60 degrees for the past 24 hours, an air conditioning system cannot be checked without possibly damaging the compressor. In this situation, it is suggested that the present owner of the property warrant the operational status of the unit on a one-time start-up and cool-down basis when warmer weather allows.
Central Air Conditioning: The major elements of a central air system include an evaporator coil and fan, condenser coil and fan, circulating refrigerant, and a compressor. The refrigerant liquid passes through an expansion device into the evaporator coil and expands to a gas which absorbs heat from the air forced over and through the evaporator coil. The cooled air is blown from the coil into an air collection chamber where it is distributed through duct work into the home. Normally a system has a life span of 12 to 15 years.
The first element requiring repair is usually the compressor. To keep the system functioning properly, you should make sure that all air inlets and outlets are not blocked and are free from dust. The air filters should be cleaned or replaced monthly in season. If there is a drain pan under the unit, the pan should be kept clean and the condensate drain open. Keep the thermostat at a comfortable setting above 78 degrees F and don’t change it. You may wish to use a set- back thermostat for energy efficiency. Insulate all duct work that passes through hot areas, such as attics. During the beginning of the season, turn on the system in advance to energize the compressor crankcase heater. Run the fan only, with the cooling thermostat set on high.