Combi Oven Troubleshooting: Fixing Common Issues

Combi or combination ovens have both convection and steam cooking features. You can use these features separately and also together for better cooking. If your combi oven is not working properly, here is a combi oven troubleshooting guide for you. If any repairs are required, consult an authorized commercial kitchen appliance repair service.

Combination Oven Cooking Problems And Their Solutions

Uneven Cooking

This is probably the most common problem related to combi ovens and other types of commercial ovens. Although this entire guide can be considered a list of solutions for this problem, in this section, we will cover the major reasons for uneven cooking.

Oven door problems are a common cause of uneven cooking. The door may not shut properly due to various reasons like dirt on the door seals, worn door gasket, or loose hinges. This will allow heat or steam to escape from the oven. Apart from uneven cooking, this will make the oven take longer to cook food and reach the set temperature.

Furthermore, heating element issues can also lead to uneven cooking. After that, the next thing to check is the temperature settings, temperature sensors, and humidity levels.

Lastly, the issue could be a human error. The operator might have used the convection feature instead of steam for cooking a certain product that must have been cooked on steam.

No Power Or Intermittent Power

As the heading says, it’s usually a power-related issue if your commercial combi oven is not turning on. You should check the circuit breaker. A flipped circuit breaker once in a few weeks is not an issue, but regular tripping of the breaker means something is wrong either with the circuit breaker or the appliances that are getting power through that circuit breaker.

Apart from that, if the combination oven is not switching on, check the power cord and the outlet. Use a different power outlet and make sure the power cord fits snuggly in the outlet. If after checking these things, the oven doesn’t turn on or shuts down expectedly, contact an expert.

Moreover, if you notice a flickering light when the oven operates, it may be a bigger problem than expected. Turn off the appliance and get a professional to inspect the appliance.

Other than power issues, another reason for an oven not turning on is the opened door. Many ovens don’t turn on if the door is open. Therefore, close the door. In some cases, the door appears closed, but it’s not completely shut. Check the door or let an expert inspect it.

Steam And Moisture Issues

Steam problems include the combi oven not steaming, excessive moisture in the oven, etc. For this, you should first check the water reservoir of the oven. Make sure that it’s filled only with filtered water. If the water is not filtered, it can affect the food quality. Plus, the contaminants like dirt can clog the steam generator.

This leads us to the next thing to check, which is the steam generator. Even when you use filtered and clean water, it can get clogged over time so you have to clean it regularly, otherwise, the oven won’t produce enough steam even when the water reservoir is full.

After checking the thing that allows steam to spread, you should check the part that removes the moisture from the oven: the drainage system. Any blockages in the drainage system will cause more moisture in the oven than what’s suitable for the food you’re cooking.

Once you have done that, inspect the door seal of the oven. This is an important of the door that creates a seal and keeps the heat and steam inside the oven chamber. If it’s damaged or worn, have it replaced. However, sometimes, dirt on the seals can cause heat leakage. So, clean the seals and the oven’s outer part.

Then move on to check the humidity controls. Make sure to set the humidity controls correctly. Refer to the user manual for noting the right settings for the food you want to cook.

The Temperature Sensor Problem

The temperature sensors maintain the correct temperature inside the oven. If the temperature sensors are faulty, the oven won’t cook food evenly, won’t cook food at all, or take more time than normal to cook food. You would input the correct temperature settings, but the result would be uneven cooking.

So, use a food-grade thermometer to match the temperature inside the oven with the temperature shown on the display. Consult an oven technician if you notice any differences.

You must get the thermocouple and other components checked as well. Even when they are fine, they must be calibrated from time to time so they detect and signal the correct temperature reading.

Oven Fan issues

The oven fans regulate the air circulation and keep it best for cooking food. Problems with them will affect the food quality. You should first check whether the fans are working or not. Sometimes, the fans are working fine, but one of the heating elements is faulty leading to bad food quality.

However, if the fan is actually not working, there may three reasons for it. The easier one is that the fan is dirty and the dirt and debris are keeping it from rotating. You should clean the insides of the oven including the fan to fix this problem.

Other reasons for a combi oven fan not working are a bad fan motor or a faulty fan element. An expert is required to check and replace them.

Combi Oven Maintenance

You must maintain and care for the oven if you want it to function smoothly with no or fewer breakdowns. Here are a few things to remember:

  • Wipe the door and the body of the oven after cooking every batch of food. This will keep dirt from building up causing the heat to escape.
  • Always use filtered water. This should be taken care of during the installation so the water reservoir receives filtered water.
  • Don’t forget to change the filter. Sometimes, when it’s rush hour, the oven shows the error message to change the filter, the staff overrides it and later forgets to change it. Make sure that this doesn’t happen. Usually, a filter is cleaned every week.
  • The oven in general, and its control board specifically, should be in a safe proximity from nearby items because any heat source from a nearby appliance can affect the temperature reading of the control board.
  • Don’t use cold water when the oven is still warm. Lukewarm water is best to use for cleaning the oven.
  • Don’t use a power washer as it can damage some delicate components. Water from a power washer can also damage the control board which is waterproof but can’t protect itself when a power washer is used.
  • Clean the drain hoses regularly to prevent any blockages.
  • Clean both the interior and exterior of the unit daily. Moreover, clean the top of the oven weekly.


To ensure that the food cooked in a combi oven is delicious and perfect, you must keep it maintained and fix common problems as soon as possible. Always hire an experienced commercial oven repair Fairfax technician for repairs.