When a Bosch dryer throws an error, it’s not trying to scare you—it’s giving you a clue. Codes E:20 through E:26 all point in the same direction: the control module (the dryer’s “brain”) isn’t happy. Below is a clear, human-friendly walkthrough of what that means, why it happens, and the smartest way to respond—without drowning you in bullet points.

What the control module actually does

Think of the control module as traffic control for heat, motors, sensors, and safety checks. It decides when to spin, when to heat, and when to stop. If it can’t reliably talk to the rest of the dryer—or it detects something that doesn’t add up—it’ll raise an error. E:20 to E:26 is the dryer’s way of saying, “My control electronics aren’t behaving.”

First, try the simplest reset

Power glitches and tiny software hiccups are real. Unplug the dryer for a full three minutes, then plug it back in and start a basic cycle. If the code doesn’t return, you may have just cleared a temporary fault. If it comes right back, the dryer is telling you the problem is deeper than a hiccup.

Why these codes show up

Control modules can fail or get confused for a few common reasons: brief voltage spikes, a sagging outlet, moisture intrusion, excessive heat, or aging components. Homes with frequent power fluctuations or older wiring are more likely to see these issues. Sometimes a loose harness or oxidized connector makes the board “think” something’s wrong, even if the rest of the machine is fine.

A few smart checks before you call for parts

Keep it safe: always disconnect power before touching anything, and don’t open the cabinet if you’re not comfortable doing so.

• Confirm the outlet is solid. If the plug is loose or the outlet is warm to the touch, that’s a red flag. Test the outlet with another appliance or a simple outlet tester.
• Look for signs of moisture around the dryer nook. Humid laundry rooms, recent leaks, or damp walls can affect electronics. Improve ventilation if needed.
• Make sure lint and heat aren’t trapped. Poor venting keeps heat in the cabinet and can stress electronics. Clean the lint filter and, if it’s been a while, have the vent run professionally cleared.

If after those basics the code still reappears, the control module is almost certainly at fault.

When replacement is the right move

Persistent E:20–E:26 after a proper reset nearly always points to a defective control board. Replacing it isn’t a “guess-and-hope” job: the board type must match your exact model revision, and handling modern electronics requires proper static-safe procedures. A trained Bosch technician will:

• Verify the code and run board-level diagnostics
• Inspect wiring harnesses and connectors for damage or oxidation
• Install the correct board, update any model-specific settings, and test spin/heat cycles

That saves you from ordering the wrong part or chasing a second, hidden issue.

Warranty and safety notes

If your dryer is under warranty—or you’re not sure—check your paperwork or serial tag before you touch anything beyond the basics. Opening the cabinet or installing parts yourself can void coverage. And if you ever smell scorched wiring or see arcing, stop and have a professional inspect it.

How to prevent a repeat

Give the new (or recovered) control module an easier life: use a good surge protector, keep the laundry area dry and well-ventilated, avoid overloading the drum, and clean vents regularly. Those small habits go a long way toward protecting sensitive electronics.

E:20 to E:26 on a Bosch dryer is the control module waving a flag. Try the clean power reset first. If the code returns, you’re looking at a control-board issue that’s best confirmed and replaced by a pro. Do the quick outlet/vent/moisture checks, then schedule service with someone who works on Bosch electronics every day—so your dryer gets back to quietly doing its job.