COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

Possible Cause

Possible Solution

 

 

Replace fuse, reset breaker. If repeats, check

 

Fuse blown or circuit tripped

fuse or breaker size. Check for shorts in unit

 

 

wiring & components

 

Power cord not plugged in

Plug it in

Unit does not run

System button in “OFF” position

Set correctly

Inoperative system button or open

Test for continuity. Check alarms. Correct

 

 

electronic control board

as needed.

 

Loose or disconnected wiring

Check wiring & connections. Reconnect per

 

control board or other components

wiring diagram

 

 

 

Problem

Possible Cause

Possible Solution

 

Dirty filter

Clean as recommended in Owner’s Manual

 

 

Check for dirty or obstructed coil. Use

 

Restricted airflow

pressure wash or biodegradable cleaning

 

 

agent to clean

Evaporator coil

Inoperative thermistor

Check alarms. Replace as necessary.

freezes up

Short of refrigerant

De-ice coil & check for leak

 

Inoperative fan motor

Test fan motor & replace if inoperative

 

Partially restricted capillary tube

De-ice coil. Replace capillary tube.

 

 

 

Problem

Possible Cause

Possible Solution

 

Excessive heat load

Unit undersized. Test cooling performance &

 

replace with larger unit if needed. See sizing chart.

 

 

 

Restriction in line

Check for partially iced coil & check

Compressor runs

temperature split across coil

 

continually & does

Refrigerant leak

Find leak and repair.

not cycle off

 

 

Compressor relay contacts stuck

Check operation of t-stat. Replace if contacts

 

 

remain closed.

 

 

 

Remote wall T-stat incorrectly wired

Refer to appropriate wiring diagram

 

 

 

 

Thermistor shorted

Replace thermistor or electronic control board

 

 

 

Problem

Possible Cause

Possible Solution

 

Compressor relay contacts stuck

Replace electronic control board

 

 

 

Electronic control

Temperature set at coldest point

Turn to higher temp. setting to see if unit

cycles off. If not, replace control board.

board does not

 

turn unit off

 

 

Incorrect wiring

Refer to appropriate wiring diagrams

 

 

 

 

 

Unit undersized for area to be

Refer to industry standard sizing chart

 

cooled

 

 

 

Defective thermistor

Replace thermistor or electronic control board

 

 

 

60

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Friedrich R-410A service manual Replace fuse, reset breaker. If repeats, check
Page 60 Page 62

R-410A specifications

Friedrich R-410A is an advanced refrigerant widely used in HVAC (Heating, Ventilation, and Air Conditioning) systems, known for its high efficiency and environmental friendliness. As a hydrofluorocarbon (HFC) blend, R-410A has become the preferred alternative to R-22, which is being phased out due to its ozone-depleting potential. One of the main features of R-410A is its high latent heat of vaporization, which allows for efficient heat transfer and improved cooling performance in air conditioning units.

Technologically, R-410A operates at higher pressures than older refrigerants, meaning systems designed for R-410A need to be built with more robust components to safely handle these pressures. This results in a more compact system design that offers enhanced performance and reliability. The dual-component nature of R-410A—composed of difluoromethane (R-32) and pentafluoroethane (R-125)—provides an optimal balance of thermodynamic properties, leading to superior energy efficiency, especially in variable speed applications.

In terms of characteristics, R-410A has a higher cooling capacity, which enables HVAC systems to effectively cool larger spaces or run more efficiently when cooling smaller areas. The refrigerant is non-toxic and non-flammable, which enhances safety during its use. In addition, R-410A has a lower global warming potential relative to other refrigerants, making it a more environmentally responsible choice for modern cooling systems.

Moreover, R-410A systems typically require less refrigerant charge due to their efficiency, contributing to reduced greenhouse gas emissions. The adoption of R-410A aligns with regulatory trends aimed at minimizing the environmental impact of refrigerants in cooling applications.

Overall, the Friedrich R-410A refrigerant embodies a combination of technology and environmental stewardship, making it a cornerstone of contemporary HVAC design. Its ability to provide effective and energy-efficient cooling solutions while being compliant with modern environmental regulations positions R-410A as the refrigerant of choice for engineers and installers focused on sustainability and performance in air conditioning systems.
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