How to Diagnose a Ruud Furnace Error Code 57

When you have an unexpected error with your furnace, it can be worrisome, to say the least. But there’s no need to panic because most furnace errors are simple fixes that you can troubleshoot easily. If you have a Ruud furnace and it’s giving you an error code, this blog post is for you! Diagnosing a specific error code on your furnace is not always easy, but we have outlined them all here for you. These quick pointers should help get your system up and running again in no time. For each of these codes, there is a specific problem that can trigger that code; they are not general codes like “over temp” or “open sensor” but rather something like “regulator failure” or “high-pressure switch failure”. Knowing what these codes mean and how to troubleshoot them will make fixing any issue much easier.

Error Code 57 – Furnace Won’t Run

When a furnace fails to start up, the error code 57 is a common one. This can be caused by a variety of issues, including a failure of the power source, a blockage in the burner area, or a clogged filter. If the power source to the furnace is not reaching the furnace, the first thing to check is the circuit breakers. An overloaded circuit can trip breakers, but a loose connection or worn-out wiring may also be the issue. To clear a blockage, shut off the main gas valve and remove the access panel. Inspect the burner area, and clean out any dust or debris that may be present. Also, ensure that the pilot is receiving enough gas to ignite. If the pilot is not firing, check the gas pressure and make sure it is set correctly. If there is a clogged filter, clean it out. This will allow the furnace to draw air through the filter and operate properly.

Error Code 58 – Furnace Won’t Turn Off

If a furnace continues to run after the thermostat has been satisfied, the error code 58 can be triggered. An improperly wired thermostat may cause this issue, as well as an over-temperature sensor or a power failure. To check an over-temperature sensor, unplug the furnace, remove the front panel, and inspect the sensor. If it is not reading above the normal temperature, the sensor can be cleared and the furnace reset. If the sensor was triggered due to high temperatures, this can be repaired by replacing it. If a thermostat is wired improperly, it can cause the furnace to continue running after the thermostat is satisfied. The easiest fix for this issue is to simply rewire the thermostat correctly. If a power failure occurs, the furnace may not shut off when the power is restored. To correct this, unplug the furnace and reset it.

Error Code 59 – Furnace Short Cycle Fail

A short cycle occurs when the furnace turns on, heats up, and then shuts off before the thermostat can register an increase in temperature. The error code 59 indicates that the furnace has experienced a short cycle. A short cycle can be caused by an air filter that is too clogged, an airflow restriction, or a dirty combustion blower. First, check the air filter and replace it if necessary. Next, unplug the furnace and remove the front panel. Use a shop-vac or your vacuum to remove any hair or debris that may be present in the blower area. To correct an airflow restriction, unplug the furnace, remove the front panel, and inspect the ductwork. Remove any clogs or obstructions to increase airflow.

Error Code 73 – Furnace Overheat Protection

Furnace overheats protection can be triggered by a few different issues. A clogged filter or a dirty blower will increase the temperature inside the furnace, which can trigger the error code 73. A faulty pressure switch or a faulty pressure sensor can also cause this problem. To correct a clogged filter, clean the filter. If it is beyond repair, replace it. First, unplug the furnace and remove the front panel. Then, use a shop-vac to remove any hair or dirt from the blower area. If the pressure switch or sensor is faulty, it can be replaced. First, unplug the furnace and remove the front panel. Remove the pressure switch cover and replace the faulty pressure switch with a new one. To correct this problem, the furnace will need to be professionally serviced.

Ruud Codes 90, 91, 92, 96, and 97 – Condenser Problems

Several different error codes indicate a problem with the condenser. Ruud furnace error codes 90, 91, 92, 96, and 97 all indicate that the condenser has issues. An issue with the fan or fan motor can cause these issues, as well as a clogged condenser or a failed pressure switch. To correct fan issues, unplug the furnace, remove the front panel, and replace the fan if necessary. To clear a clogged condenser, unplug the furnace, remove the front panel, and clean the condenser. To correct a failed pressure switch, unplug the furnace, remove the front panel, and replace the pressure switch.


A furnace is a complicated piece of equipment, and it can fail for a variety of reasons. As a homeowner, you should know how to troubleshoot the most common problems. This will help you save time and money. And if you ever need to call for service, you can describe the issue to the technician and he or she will have a good idea of what the problem is. With an understanding of these common furnace errors and how to diagnose them, you can easily troubleshoot any issues with your furnace. So whether it’s a short cycle, a clogged filter, or an overheat protection, you’ll be able to fix the problem quickly.