You just get home from work and get ready to warm your supper dish, setting your wall oven for convection baking at 350°F (180°C). You then start preparing your side dishes to complement that meal you’ve been planning all afternoon to cook while waiting for the oven to "beep" when it reaches the 350° mark.
But after about 5 minutes, what you hear instead is a “chirping" sound coming from the oven, and looking at the screen, you find a disarming message that spells "F23 ERR" instead of the expected 350°.
Electronic Control Boards Fault Codes
Most if not all electric ranges and ovens controlled from an electronic control board—either the ERC (electronic range control board) or the EOC (electronic oven control board) have digital displays.
If the display is blank with none of the buttons working even after checking the fuses and breakers, it is very likely that either the ERC or the EOC board has failed, especially when you get a good voltage reading at the power terminal.
But the control board can also be defective with a display still on and changing as you press the touchpad and might even emit sharp beeps. This tells you that even though some section of the electronic board is still operational, it is malfunctioning at some other level.
Those ERC and EOC boards are programmed to recognize some of the possible common problems likely to happen in appliances and warn you on the display while emitting a specific sound.
Whenever your range or your oven decides to give a fault code, panic may quickly set in as you have to dig up your owner's manual and, more often than not, come out from your research even more confused than ever about the meaning of the code.
A lot of people will end up searching online or calling the local appliance repair shop, which can prove to be very informative in some cases. A technician can effectively give you a feel of what might be the cause and how much money you're in to spend fixing it.
If you've had your range or wall oven for several years, it might be a good time to consider the purchase of a new unit as opposed to fixing the old one.
If the problem has to do with a defective electronic control board—although they were always quite expensive to replace—you'll probably find that their replacement cost has increased considerably since before 2020.
But since prices have also been dramatically increasing for appliances in general in the last few years, repairing them still remains a very viable option.
Electric Range Oven Versus Wall Oven
Doing repairs on an electric range is much easier than on a wall oven since all that you have to do is pull it away from the wall, unplug the unit, remove the back panels (if needed), and lift off the top cover.
The rest of the troubleshooting for an oven fault is basically done the same way as for a wall oven. This summary, however, was written about doing repairs on a Kenmore Wall Oven model C-970 and will relate specifically to the steps followed to repair this particular model.
But even if your oven or range or oven is of a different make or model, the troubleshooting methods and techniques would still all remain pretty much the same or very similar, once all covers are removed, and you get a visual of all of its electronics.
The F23 Fault Code
If the display on your control panel still lights up and the control board provides you with a fault code reading, this particular fault code will pinpoint the problem to the actual cause of the malfunction. A fault code can also be accompanied by sharp beeping or chirping alerts.
When you get a fault code "F23 ERR" (Figure 1) accompanied by a sort of chirping noise, F23 indicates that the issue is caused by a miscommunication between 2 boards—the main control board and another PC board situated at the back wall of the oven box.
This other board is the convection control board, whose main function is to control the oven lights and activate and control the variable speed of the convection fans.
Therefore, an "F23 ERR" code will only occur on convection ovens, as it confirms that a signal sent from the main control board cannot get through to the convection control board in order to activate or control how and when the convection fans should operate.
This code, therefore, would come from 1 of 3 possibilities, such as a defect in the cable that connects the two boards together (Figure 2). That would be the cable with the blue connector.
Another possibility is a failure on the main control board in processing or sending the proper signal, and the 3rd possibility is a defective convection fan and oven lights control board, which is the most common problem with the F23 and F24 faults.
Getting Access to a Wall Oven's Electronics
A wall oven will present you with a few challenges while trying to get access to its electrical circuitry. As you pull it out from the wall, the center of gravity of the unit will shift outwards.
As you will need access to the top and the back of the box (Figure 3) without worrying about holding the oven at the same time, you'll have to conceive some reliable system of supporting the shifting weight of the unit while working on it.
In this particular case, where the cabinet was built with three large drawers equipped with heavy-duty full extension glides (Figure 4) directly below the oven cavity, building up a reliable support was an easy enough solution.
By pulling out the top drawer, the space between the drawer and the underside of the oven box was conveniently filled by stacking several pieces of wood to take up the slack.
A piece of plywood can then be used as a platform, sitting on the built-up drawer at the front end and onto the lower edge of the oven cavity inside the cabinet at the back.
If all your cupboard has, however, is a set of doors with regular hinges or drawers mounted on regular-duty glides, you should find an alternate method of support for extracting your oven box.
This will require you to build a stand that will support the platform at about 18 or 20 inches (46-50 cm) away from the wall or the front of the cabinet once secured in place to the bottom edge of the oven's orifice.
A solid support stand will require two legs standing about 32 inches (81 cm) apart and joined together at the bottom with a 32-inch stretcher or board. Making the stretchers from wider boards will also provide better stability to your apparatus, keeping the two legs apart and parallel at all times.
You will also need to add a 2nd "stretcher" at the top that will be screwed in, holding the upper end of the legs apart at the same width as the bottom.
This stretcher will maintain the whole frame square and also provide a cross-bar for supporting the platform at the top. Either screwed to the edge or on top of the vertical legs, make sure that the overall height of your frame is the same height as the bottom edge of the cabinet or wall opening for the oven box.
Such a setup, however, will need to be solidly secured in place as described in step 3, in order to provide a surface that is secured to the cabinet or the wall opening to prevent you from dropping the oven box while sliding the unit in or out of its cavity or while you turn it to reach around the back of the unit.
Get Access to the Electronics
Although this repair job refers mostly to the Kenmore Wall Oven model C-970, it has a lot of similarities with different brands and models of ranges and wall ovens.
But on whatever brand or model, if you get any type of fault code on your digital panel screen, the first thing to do is to try to reset the PC board. If that doesn't work, you'll have to get visual access to the inside wiring and electronic components, which means getting the top shield (or the range top) and back covers off.
1. Always Do a Reset on the Main Control Board
The very first step to take when your oven starts acting up is to unplug it from the wall outlet, and if it is hooked up directly into your breaker panel, locate the right breaker inside the panel, switch it off for a minute or so, then switch the breaker back on.
This action just might initiate your PC Board into a reset. Once this is done, try again to turn your oven on again to see if the problem is still there. If it's still defective, turn the breaker off again and proceed to step 2.
2. Remove the Door and the Trims
The oven door, with its thick and heavy glass window, adds a lot of weight to the oven box and shifts the center of gravity to the front of the unit. It is usually easy to remove and set aside.
On this particular oven, the door must be removed next by pulling out the tabs at the top of each hinge, then pulling it slightly open. You can then grab the handle and lift the door straight up to disengage the hinges and remove the door.
Once out, look at the trim below the door opening, and you'll see on the underside a screw at each end. Remove those screws and take off the bottom trim.
3. Install and Adjust the Working Platform
In order to gain access to the wiring/electronics of the Kenmore C-970 or most other models of wall ovens, you'll have to remove two screws securing the oven box into its cavity in order to be able to pull the unit out.
Once both screws are out, make sure that the oven box moves freely inside its cavity. Lift the oven 2 to 3 inches (50-75 mm) at the bottom and insert the inside edge of the platform inside the orifice for the oven.
Make sure that the device's legs are placed perfectly vertically and that the platform stays solidly in place without too much movement.
A good way to ensure that the platform will not move is to add a wood trim 3/4 x 3/4 x approximately 6-inches (19mm x 19mm x 150mm long), placed flush to the edge of the platform, and under it to form a stopper against the inside of the cabinet frame or the wall and keep the platform from sliding out.
Another wood trim can also be placed and screwed on the outside to keep it from moving in.
4. Remove the Control Panel
Pull the oven box out about 10 inches (25 cm). You now have a clear view of the control panel and see that it has a hanger pin at each end that hooks it to the side filler trims that extend at both sides past the height of the oven box.
The control panel can be removed by extracting the three screws that hold it underneath the oven box via a flat plastic trim. Remove the control panel but leave the EOC board attached to it. Unplug the cables from the EOC board and set the control panel aside.
You'll have to proceed very carefully with disconnecting the connectors as most of them are equipped with a special locking clip.
Proceed very carefully and try first to identify how they work to disengage them properly. Figure 5 shows the EOC disassembled from its control panel with the touchpad.
As the top part of the side filler trims at the front of the oven box is likely to get caught and bend at the top of the orifice, they should also be removed from the oven box.
5. Remove the Top and Rear Shield Covers
With your DIY support stand in place, pull the oven box 3/4 of the way out. You can now rotate it upon itself to expose the back wall to the side. Remove all the screws holding the top’s front shield(s) in place and remove them.
The larger top shield at the back could remain in place. Remove the rear shield also. The top and back of the oven are now exposed to view, as shown in Figure 6.
6. Check the Wiring
If you look at the back of the oven box, you should see a small PC board attached to the back wall (Figure 7). This is the most likely component to cause an "F23 ERR" code.
You can see where the black, red, and yellow wires from the main control board plug into this convection control board through the blue connector. The other end of that same cable also plugs into the EOC board through a blue connector shown in Figure 2.
Do a visual check of the wiring for burnt, cut, or otherwise damaged wires and connectors. If all looks good, take your multi-meter and do a continuity check on each of the 3 wires leading to the convection fan and oven lights control board.
If you find a damaged, shorted, or open wire, repair it, or if it's not possible, for a damaged connector, replace the cable with a new one.
7. Replace the Convection Fan and Oven Lights Control Board
If the cable proves to be in good condition and functional, you'll have to assume that the problem comes from a defective convection fan and oven lights control board.
This PC board is actually the most common cause of an F23 ERROR fault with an oven. Unplug the two cables leading to the convection fan and oven lights control board and remove the board from the back wall of the oven.
If you turn the board around and look at the other side, you should see a number following the letters "P/N" stamped on the board, as shown in Figure 8.
Use that number to order a new part and when you get it, install it and plug the cables in. Your oven should now work, but if it doesn't, check the cables at both ends to ensure they're properly plugged in.
But before investing in an older appliance, you should also check for the availability of the main control board and its cost. An EOC and ERC board could also be a possible cause—as described in step 8—and these PC boards often go obsolete after a few years, making them difficult to find
8. Replacing a Faulty Main Control Board
There is no way for you to properly check the functionality of the convection fan and oven lights control board, but one thing for sure is that it costs only a fraction of the price you would pay for the main control board, besides it being the most common cause of that fault code in an oven.
So this makes it the most logical part to replace before considering the next step.
With a new convection fan and oven lights control board installed and the cables duly re-checked, you're now down to just one more possibility—the EOC or the ERC board.
Even though this PC board is not as common for causing an F23 fault, you’re now down to this last possibility, and you need to replace it with a new one.
Double Wall Ovens and the F24 Fault Code
If you have a double wall oven, the same problem could easily happen with the lower oven but show you an "F24 ERR" instead of the F23.
The problem is exactly the same as described above, except that F23 refers you to the upper oven having a problem while F24 lets you know that the problem has to do with the lower oven.
Each oven has its own convection oven fans and light control board, so if this is your case, you can replace the defective board with the operational one to rule out the main control board.
If you'd like more tips on troubleshooting and repairing ovens and ranges, you can find many more on our site, like these: