Emerson Thermostat Flashing Snowflake? (We Have A Fix!)

Dennis Howard
by Dennis Howard

Modern electronic thermostats are a marvel of convenience. Thermostats, such as some Emerson models, communicate with your HVAC system to give you information about your system’s current status. It is important to understand how the thermostat communicates with you. A flashing snowflake icon on an Emerson thermostat may be a normal occurrence or may indicate a problem with your HVAC system

If your Emerson thermostat flashes a snowflake icon, the HVAC system has gone into a time delay mode. This time delay mode is usually caused by short cycling in the system. Airflow problems, faulty sensors, or electrical problems can cause short cycling and should be resolved to reset the thermostat.

To resolve a flashing snowflake icon, you must understand what can cause this condition. This also requires some knowledge of your HVAC system components. In some instances, a homeowner can easily diagnose and remedy the problem underlying the flashing snowflake icon. In other cases, a visit from an HVAC technician is your best course of action.

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What is My Emerson Thermostat Trying to Tell Me with a Flashing Snowflake?

More than likely, the message your Emerson thermostat is sending to you when it flashes the snowflake icon is to be patient. The thermostat has detected a situation where your condensing unit outside your house is having problems. The usual form of the problem is called short-cycling, which can damage your condensing unit if allowed to continue.

A flashing snowflake icon on an Emerson thermostat may indicate other problems. Some of these problems can cause a short-cycle situation. In some instances, the problem may be deeper than a short-cycle issue and require more diagnostics and expertise from a trained HVAC technician.

What is Short-Cycling?

Short-cycling is a condition when your HVAC unit starts, runs for a few minutes and shuts off. The cycle usually repeats quickly. This repeated rapid on and off cause premature wear and tear on your HVAC system and the condensing unit in particular.

There can be several causes for short cycling. Before you begin trying to diagnose a short-cycle problem with your HVAC, you should understand these problems. Understanding what can cause short-cycling will allow you to recognize possible problems and know when your best choice is to call in an HVAC technician.

Too Much HVAC System Capacity

If your HVAC system is too large for your home, one result can be short cycling. The HVAC system cools or heats your home too quickly and then shuts down. Typically, the cooling cycle will repeat every few minutes because the ambient temperature in your home rises quickly after a short cycle of operation.

This is hard on your HVAC system in several ways. Rapid heating and cooling can damage the heat exchanger if the HVAC system is short-cycling during a heating cycle. In addition, every time the blower motor starts and stops, it adds wear and tear that can shorten the motor’s life.

During a cooling short-cycle, the big danger is damage to the condensing unit and compressor outside your home. Starting the compressor motor requires much more electricity than running. Each time your compressor motor starts, it undergoes stress that can eventually cause the motor to fail. Short cycling adds to that stress and well as puts wear and tear on your compressor.

If your HVAC system is short-cycling, you should contact an HVAC specialist to do a survey on your home. These technicians are trained to evaluate your home and calculate the proper size HVAC system. If your HVAC system is too large, the technician may recommend that you downsize the system.

Electrical Issues

The lifeblood of your HVAC system is the electricity that drives the motors, compressors, and electronics that operate the system. If there is a problem with the electrical power, your HVAC system may begin to short-cycle.

When it comes to supplying power to your HVAC systems, there are not many things a homeowner can check. The root causes of power delivery problems usually can be traced to one or more of several issues.

  • A power surge through your electrical system may damage the HVAC system components. This is not unusual in areas where thunderstorms and lightning are common.
  • In some older homes where an HVAC system has been updated with new equipment, the wiring in the home may not be adequate to supply the new HVAC system
  • A faulty circuit breaker can cause intermittent problems with power delivery to the HVAC system that can result in short-cycling

In any case, diagnosing and repairing damage or inadequacies in the electrical wiring that serves your HVAC system is not a DIY issue. You should consult with an HVAC technician or a licensed electrician if you think there is a problem with the electrical circuits in your home.

Control and Regulation Issues

Modern electronically controlled HVAC systems have multiple sensors that control and regulate the operation. If one or more of these sensors is faulty, the result can be a short-cycle situation or a complete failure to start.

Many HVAC system control boards have LED or LCD displays that flash error messages when a problem occurs. Your owner’s manual probably has a list of these error codes. However, even if you can decode the signal from the control board, making the repair usually requires a trained HVAC technician. This is particularly true if your HVAC system is still under warranty.

Air Flow Issues in the HVAC System

Your HVAC system depends on moving air efficiently through the ductwork. If something is impeding that airflow, the HVAC system may begin to short-cycle. If the HVAC system cannot move air efficiently through your home, it must work harder.

Perhaps the most common problem leading to airflow problems in an HVAC system is clogged or dirty air filters. Every HVAC system manufacturer makes recommendations on the type of air filters to use and the frequency of air filter changes. You should follow these recommendations closely for the best efficiency from your HVAC system.

Another less likely issue is a clogged or blocked air vent or ductwork. If you suspect that a piece of your ductwork is clogged or damaged, you should consult an HVAC technician to perform an inspection of your ducts. In some cases, the HVAC technician can evaluate the airflow in your system and adjust the outlets to create a balance that will solve short-cycling problems.

Thermostat Installation Problems

Many homeowners upgrade the thermostats in their homes. Usually, a thermostat replacement is a straightforward and easy project. However, failing to install the thermostat control wiring properly can lead to problems with your HVAC system. These problems can include short-cycling of the system.

The location of a thermostat can also cause short-cycling problems. You should avoid locations where the thermostat is in direct sunlight from a window or door. Locations the receive a direct draft from a duct outlet can cause problems as well. Consult with an HVAC technician if you suspect your thermostat is in a bad location.

I Repaired My HVAC System, but the Snowflake is Still Flashing

In some cases, the snowflake icon on your Emerson thermostat may continue to blink and remain in lockout mode even after a repair. In this case, you must perform a reset on your thermostat. Each Emerson thermostat model has its own reset procedure. Your user manual has the steps required to perform a full reset of your Emerson thermostat.

In general, an Emerson thermostat can be reset using these simple steps. If this doesn’t work with your Emerson thermostat, consult the user manual for more detailed instructions.

Step 1: Press the Up, Down, and Menu Button Simultaneously

This requires a bit of manual dexterity. You must press all three buttons simultaneously and hold them down until the display on the thermostat blinks. This is the signal that the thermostat has reset.

On some Emerson thermostats, the button combination is the timer button, the up button, and the down button. Again, watch the display on the thermostat for an indication that the reset has been completed.

An alternative method is to remove the internal batteries from your Emerson thermostat and wait for about two minutes. This will reset the internal memories and put your Emerson thermostat back in a factory setting.

Step 2: Test the Thermostat

Set the thermostat to your desired setting for heat or cool. Let the system start. If the system begins to short-cycle again, you have problems that you haven’t addressed.

Step 3: Re-Enter Your Schedules and Settings

If the thermostat operates properly and your HVAC system doesn’t indicate any other problems, you can re-enter your scheduling and other settings into the memory of your Emerson thermostat.

Do You Need Your Thermostat Repaired or Reprogrammed?

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Listen to Your Emerson Thermostat

Your Emerson thermostat can provide you with a wealth of information about your HVAC system and its efficiency. Paying a little attention to what your Emerson thermostat tells you can prevent major problems further down the line. A blinking snowflake may seem like an insignificant item but, failing to recognize a problem can cost you much more in the long run.

Dennis Howard
Dennis Howard

Dennis is a retired firefighter with an extensive background in construction, home improvement, and remodeling. He worked in the trades part-time while serving as an active firefighter. On his retirement, he started a remodeling and home repair business, which he ran for several years.

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