Outdoor Units

Outside Unit Is Frozen Heat pumps do ice-up in the winter time. It is normal for the entire coil to be covered in a white frost during certain weather conditions. It is not normal for the entire unit to be encased in ice, including the top of the unit and the insides of the coil for an extended period of time. This should be addressed quickly to save energy and avoid serious damage to the equipment. Heat pumps will naturally ice-up in the winter but will periodically go into a defrost cycle to clear the coils. This keeps the unit running efficiently. If the coils are blocked by ice, proper heat exchange between the refrigerant and the outside air cannot occur. Different heat pumps have different ways of determining when to go into defrost. Some use mechanical timers in conjunction with a defrost thermostat mounted to the outdoor coil. If the thermostat is cold enough and enough time goes by, the unit will go into the defrost mode whether it is iced-up or not. When the thermostat heats up to a certain temperature, defrost is terminated. If a heat pump is severely iced-up in the winter it is possible that it isn't defrosting but there are many other causes. h2. Here is a partial list of possible causes. * Bad defrost control or timer * Bad defrost sensor * Bad reversing valve * Bad outdoor fan motor * Low refrigerant charge * Outdoor coil blocked - possibly with leaves or snow drift * Leaking gutter dripping water onto top of unit * Freezing rain - causes top of unit to freeze over - once this happens the rest of the unit will also freeze over. h2. Some items you can check * If the top of the unit is covered in ice, turn it off and remove the ice. * Keep snow and leaves away from unit including underneath it. * With the unit off, ice can be removed with a garden hose or warm water. * If the unit ices-up again, it is time to schedule a service call. * Never use sharp or hard objects to remove ice...This could cause damage * Never open any access panels, this needs to be done by trained, qualified service technicians. h1=. Outdoor unit won't come on Many times the service technician is dispatched only to find a simple problem that did not need a service call. Sometimes resulting in an unnecessary service fee. h2. Here is a partial list of causes. * Bad thermostat * Bad contactor * Bad time-delay relay * Off on a safety device ** low pressure ** high pressure ** high temp. * Thermostat not set * Emergency or shutoff switch turned off (Beside furnace if applicable) * Circuit breaker tripped or off- (sometimes a breaker will trip but it won't move or the handle moves to the middle position) * Condensate pump safety switch opened * Unit "locked-out"- (reset by turning off wait 1 min. then turning back on.) h2. Here is a checklist to go through before making a service call * Make sure there is a call from the thermostat * Make sure no Emergency switches are turned off (including the switch on the side of the furnace) * Make sure the breakers for the indoor and outdoor equipment are in the "on" position- turn off, then on if not sure * If you have a condensate pump with a safety switch, check to see if the pump is completely full of water- If so, make sure pump is plugged-in and the hose isn't clogged * If your outdoor unit has a "Reset Button" press it- if that works for awhile but you have to press it a second time, there is a problem * Your unit could have a safety device locking it out. Reset it by turning system off at thermostat or breaker, wait 1 minute and turn back on. - Wait 5 or 6 minutes to see if outdoor unit starts