Start up with a night set back digital thermostat requires the technician to always;

On a time initiation/temperature termination defrost, the defrost time clock has one N.O. And N.C. switch. When do the positions of these switches change?

What control operates the 1st stage of secondary heat?

The defrost cycle can be initiated by;

What type of defrost is employed on this heat pump?

During the heating cycle, the outdoor coil is use as;

Air-to-air heat pumps are most practical to operate in areas where the lowest winter temperature does not go below ______ *F

Which of the following are innovations that may be found on new high efficiency units?

In order to determine a heat pumps' balance point, you must first calculate;

When installing the heat pump outdoor unit, care should be taken to provide for drainage during the ________ cycle.

When a heat pump is in the heating mode, which can cause frost accumulation on the outdoor coil when the ambient temperature is 45*F?

What is the recommended CFM across the evaporator cool of a heat pump?

The reversing valve is often referred to as a;

You answer a service call for insufficient heat. You find the suction pressure is higher and discharge pressure is lower than normal. Using a digital thermometer, you measure the line entering the reversing valve from the compressor discharge and find 215°F. You then measure the line leaving the reversing valve that connects to the indoor coil and find 185°F. These readings are an indication of;

Off-cycle crankcase heat is provide by;

During the defrost cycle, the system switches to the ___________ Mode.

Room thermostats for heat pumps should be installed;

A scroll type compressor;

Refrigerant flow through the compressor;

The most common method of defrosting the outdoor coil on an air source heat pump is;

Compressors designed for heat pumps differ from compressors designed for A/C in that;

When operating in the cooling mode, hot gas leaves the compressor and first flows to;

The defrost cycle can be terminated by;

During the defrost cycle, the outdoor fan is usually;

Since electric resistance heat produces 1 watt of usable heat for each watt of energy purchased, electric resistance heat has a COP of;

What is the industry standard for deep vacuum?

A heat pump has a thermostatic expansion valve (TEV) and a check valve at each coil. When the modes are reversed;

The air-to-air heat pump outdoor unit is most efficient if located;

Some heat pump systems use a _______ as a metering device.

What is the difference between "demand defrost" and "timed defrost"?

One of the most important devices to insure the longevity of a heat pump's reciprocating compressor is the;

The indoor coil is usually mounted in the air stream _______ the auxiliary electric heat strips

Which component is responsible for changing the direction of the flow of refrigerant?

Heat pump mode efficiency is rated in;Heat pump mode efficiency is rated in;

A heat pump system, operating at 45°F ambient, may be _______ efficient than electric resistance heat

Some close coupled (package unit) heat pumps use an electronic expansion valve is

The indoor fan on a heat pump system operates;

When the heat pump compressor has malfunctioned, the customer has the option to switch the system into;

What is the most common complaint from a customer changing from gas heat to a heat pump?

At what temperature is an outdoor ambient thermostat normally set?

The most preferred method of charging any system in the field is;

On a split system heat pump. A "no heat/no cooling" service call, you turn the thermostat to the fan on/ cont position and the indoor fan operates. This action verifies that;

The thermostat that controls the auxiliary electric heat according to the outdoor temperature is called the

The outdoor temperature at which the heat pump provides the same amount of heat as the heat loss of the conditioned space without an auxiliary heat is known as the;

High efficient heat pump systems charged with R-410A refrigerant normally use a;

How is defrost terminated in this system?

During the heating mode, the refrigerant in the indoor coil is under;

On most air-to-air heat pumps;

Heat pump systems which use a thermostatic expansion valve at each coil will also have;

The preferred method to preform adjustments to the refirgerant charge in a heat pump system is in the ________ mode

An air-to-air heat pump has many of the same components as an air conditioning system. The major difference is that a heat pump also has an…

When a heat pump is operating in the cooling mode, the;

Which component is responsible for energizing auxiliary heat during the defrost cycle?

If manufacturer specifications are not available, a good way to calculate cubic feet per minute through a coil is to;

Mechanically troubleshooting a reversing valve can be done by;

The heat pump defrost board can be manipulated by the technician to;

An R410A heat pump operating in the heating mode has a suction pressure 50 PSIG and head pressure of 285 PSIG has a compression ratio of;

When a heat pump is used for heating and cooling, the system is sized by the

Movement of the piston in the reversing valve is accomplished by;

In the heat mode, the suction line entering the compressor contains;

Good service practice for installation of a reversing valve includes;

In addition to heat from the outdoor coil, a heat pump in the heating mode will get heat from

How may a lockout (impedance) relay be reset?

The slide valve and piston in the reversing valve is actuated by pressure directed through the;

You are starting-up a split system heat pump for the first time.the outdoor ambient temperature is 60 F. You check the temperature split across the indoor coil in the heat mode and find it is 38 F. You switch to cooling mode and determine a temperature split of 29*F. The most likely corrective action (relative to airflow) is;

A heat pump can be difficult to charge properly because;

On a water source heat pump, the heat mode water regulating valve must be;

On Dual Fuel Systems, the indoor coil must be located;

If the indoor fan is operated at an excessive speed in the cooling mode;

The temperature difference between the 1st and 2nd bulbs for heating on a heat pump thermostat is;

A high efficiency heat pump system designed to function from high to low ambient conditions below 10*F, may have?

Because of the possibility of liquid flood-back, a heat pump that uses a reciprocating compressor should be equipped with a;

What is the industry standard for maximum duration for defrost?

Liquid line filter-driers that are used on heat pump system;

You are checking for proper airflow in CFM on a three ton heat pump system. The system has one return grill measuring 24"X24", which has a net free area of 3.4 square feet. You measure air velocity and calculate an average of 400 FPM. From this information you can conclude that;

As outdoor ambient air temperature decreases, a heat pump's COP;

When a heat pump is operating in the heat mode, the suction line at the compressor;

The use of a scroll type compressor on a heat pump can eliminate the need for a;

Which type of heat pump does not require a defrost cycle?

Where is the LLP physically located in this system on this heat pump?

When operating in the heat mode, hot gas leaves the compressor and first flows to;

When this unit switches to the heat mode, select the sequence of events which will take place.

A customer complains that their heat pump systems blows cool air periodically during the heat mode. This could be caused by;

What would be the result of closing registers in rooms that are uninhabited while operating in the heating mode?

The outdoor coil is frozen solid on a "no heat" service call. The most likely reason is;

SEER is calculated by

A heat pump operates satisfactorily in the cooling mode, but not in the heat mode. This could be caused by;

When in the cooling mode, the low pressure refrigerant vapor leaves the reversing valve and tracked to the;

During the cooling cycle, the indoor coil becomes;

The DTC and cam will close the DTC N.O. contacts momentarily (approx. 5 seconds). How is the DFR kept organized when the DTC N.O. contacts open?

What three things happen in most air-to-air heat pump during defrost?

An R-410A heat pump operating in the cooling mode has a suction pressure of 131 PSIG. Adding 2 PSIG for pressure drop in the coil, the true outlet pressure is 131 PSIG. The temperature of the suction line at the outlet of the evaporator is 57° F. What is the superheat?

The customer complaint is not enough heat. You install service gauges and find the low side pressure is higher than normal and the high side pressure is lower than normal. You switch to the cooling mode and find the pressures are normal. The most likely cause of the problem is;

COP is the abbreviation for;

Air-to-air heat pumps, operating without auxiliary heat, provide air to the registers that is approximately _______ *F or less.

At temperatures above 45 degrees *F, the heat pump refrigeration cycle permits the;

High suction pressure and low discharge pressure on a heat pump system operating in either the heating or cooling mode can be an indication of;

To make the reversing valve slide move, the system must have a pressure difference of;