SYSTEM OPERATION AND CONDITIONS
Dirt is the number one cause of service calls, system failures and loss of efficiency. Dirt or dirty filters are involved in nearly every problem or issue listed below. Keep systems clean! Regular maintenance is required twice a year to keep systems clean, safe, efficient and operational. Filters clean or replace:
Home owners should check or replace their filter before or at the time of setting a service call. Dirty filters can cause or aggravate most heating and cooling problems, dirt or dirty filters are involved in nearly every problem or issue listed below. Dirty filters reduce the capacity of a system, lower efficiency and effect operation. Replace regular filters monthly or as needed, write the date of install on any filter at the time of installation. Clean permanent filters or air cleaners need as per MFG specifications.
Erratic thermostat operation may be due to batteries. Replace the batteries twice per year during time changes. Do the same for smoke and carbon monoxide detectors. Carbon Monoxide issues:
Turn off the appropriate appliance. Call an appropriate authority based on the circumstances (fire dept.-HVAC contractor-utility co.). Ventilate the space. Exit the building if needed. Check occupants for illness, flu like symptoms or worse. If warranted seek medical attention. Multi level homes require a detector on each level, generally the battery-operated type are preferred to plug-in type. Smells of smoke or gas or fumes: Shut down the appropriate appliance. Call an appropriate authority based on the circumstances (fire dept.-HVAC contractor-utility co.).
Exit the building if needed.
Turn off the humidifier at the humidistat. Check for obvious plugged drain conditions. Humidifiers normally only function during the heating mode. Water leaking, furnace: Check for obvious plugged drain conditions. If conditions allow turn it off until a technician can check it. Water leaking cooling, system: Check for obvious plugged drain conditions. If conditions allow turn it off until a technician can check it.
If there is a problem, water may show up on the floor etc. Some pumps have a safety switch that will shut the system down if there is a problem with the pump or its drain tube, sometimes shaking the pump may get it to operate again. Long run cycles: See dirt and filters above. If it’s a cooling or heat pump system, low refrigerant could be an issue. If it’s over heating or over cooling, a stuck control is likely. A system will run nearly 100% of the time at design conditions.
See dirt and filters above. If it’s a cooling or heat pump system, low refrigerant could be an issue. If it’s over heating or over cooling, a stuck control is likely. A system will run nearly 100% of the time at design conditions. Design conditions, set point: the Thermal Balance Point The point where a space (home) loses or gains heat at the same rate a system can deliver heating or cooling, it may run 100% of the time under these conditions Minimum design conditions in Dayton is heating 4°, cooling is 89° @ 75° indoor stat setting, however most systems are capable of lower winter temperatures. HP will start to run near 100% of the time at approximately 25 to 30° and colder, each home is different, at this point the auxiliary heaters will supplement the HP. System performance questions:
Fuses or circuit breakers are safeties. If they have a failure you need to know why. Breakers may appear closed but are really not. Turn them off with force and then re-set. Some breakers are located inside the electric air handler of heat pump systems. Only replace with a fuse of appropriate type and size. If a fuse or circuit breaker fails more than once, a service call is needed.
If the system runs on LP or oil, check the fuel level. If it’s an older gas or LP furnace, check to see if the pilot is out. Sometimes a system just blows cold air. This is indicative of a safety control being tripped or opened. A service call is needed in these cases.
Check breakers, fuses, door positions on furnace, filters or excessive dirt on the outdoor unit. The outdoor unit may have a clogged coil. If so, hose it off with a garden hose.
If frequent starting and stopping is a problem, shut unit off and check filter. Conditions may be a bad motor, loss of refrigerant, dirt in coils, etc. A/C or Heat Pump iced up in cooling season: Turn unit off immediately! Check air filter in furnace first. Then restart unit after 6 hours. If filter is fine, the problem may be a refrigerant issue such as loss of Freon. A/C or Heat Pump iced up in heating season: If it is and air conditioner, there is a problem. Shut the system off. If it is a HP, it is likely a defrost issue. During periods of extreme cold a unit may not 100% defrost.
If in doubt about defrost conditions, switch to emergency heat until the system is checked by a technician. Emergency heat won’t come on: Check the breakers or fuses for units affected.
Check to see if the furnace door is properly secured to the furnace. There are fuses in the outdoor disconnect box for outdoor unit. They may have gone bad. Wiring issues and some venting issues may prevent a system from starting or running.
See long run cycles above. This would predominantly be a control or wire short issue Noise indoor unit: Depending on the noise the most likely thing to make noise is the blower or vent motor.
Rattles are common, as is whistling noises caused by air going through tiny holes. Motor bearings or wheel balance may be the issue. Sometimes controls will make a clicking noise. That may or may not be normal. Sometimes a gurgling noise is made by the refrigerant going through the pipes. The thermostats on newer units make a click when they engage.
Most commonly outdoor noises are rattles. Fan related noises are common. Excessive noise from a compressor may indicate a pending compressor failure. A normal defrost cycle creates a noise. A HP should defrost every 45 to 90 minutes of run time. The fan will stop outside-there will be a whooshing noise-and steam may be seen rising out of the heat pump. After several minutes it will resume normal operation.
Poor performance is usually related to a dirty system or a system in need of maintenance. Low refrigerant. Too many duct dampers or registers closed. Wiring issues.
Gas or refrigerant pressure adjustment required
Dirty filters. Motor or motor control failing. Dampers need adjusted. Restricted duct system and or return and supply registers. In cooling-mode ice may block airflow. Ice would be indicative of other problems.