Bosch Dishwasher Lights Flashing and Will Not Start

Modern Bosch dishwashers are a lot tougher than their predecessors. They come with self-diagnosing modes that inform users what sort of problem it’s currently experiencing, so resolving the problem doesn’t take much effort. However, what should you do if your Bosch dishwasher’s light won’t start and its light begins flashing?

The likeliest cause of your Bosch dishwasher flashing red light and not starting a wash cycle is that you didn’t close the door quickly enough. You have roughly 3 seconds to shut the dishwasher door after pressing the start button, or it will begin flashing red light.

However, that’s not the only cause of your dishwasher not commencing a wash cycle. In this guide, I’ll go through the various causes of flashing light and how to resolve them.

My Bosch Dishwasher’s Red Light Won’t Turn Off

For those new to Bosch dishwashers, seeing a red light on the ground can be a sign of concern. After all, red is usually associated with problems.

However, in the case of Bosch dishwashers, if the red light won’t turn off, that means your dishwasher is in working order. Because Bosch dishwashers are almost whisper-quiet, it can be difficult to gauge whether or not the machine is even on, let alone doing what you commanded it to do.

The red light at the bottom of the dishwasher should remain on—i.e., not blink. When it turns off, that means the dishwasher has turned off or that it has just completed its wash cycle. It’s only when the light begins blinking that you need to be slightly worried.

What Does the Flashing Red Light Mean?

Bosch dishwashers are designed with flashing red lights pointed at the ground. When the light begins flashing or blinking, the machine has an error that stops it from starting a new cycle or resuming its current cycle.

Causes that Trigger the Flashing Red Light and Their Solutions

The red light can begin blinking due to several different issues. I’ll explain the most probable causes behind the flashing red light and what steps you need to take to resolve the issues.

Forgot to Press the Start Button

On the control board of a Bosch dishwasher are multiple cycle options and optional add-ons (sanitize, rinse, half-load, etc.). Oftentimes, people remember to input the wash cycle and add-ons but forget to press the start button before closing the door. When this happens, the Bosch dishwasher will begin flashing red.

Solution: Press the start button

This problem can be solved by pressing the start button before shutting the door. After pressing the start button, you have about 3 seconds to shut the door completely before the dishwasher begins filling with water. If you fail to shut the door within the allotted time, you will have to open the dishwasher door and press the start button again.

Dishwasher Door is Open

The dishwasher’s door doesn’t just keep the water inside the tub; the microswitch inside the latch tells the dishwasher that it’s safe to begin washing. If the dishwasher’s door is open, the dishwasher won’t do anything, even if you input different cycle commands. Leave the door ajar for too long and the red light will begin flashing.

Solution: Shut the dishwasher door

Again, a simple problem with a simple solution. Just shut the dishwasher’s door when you see the flashing red light. However, there are other problems associated with the dishwasher door that you can read about here (can’t open a dishwasher door) and here (broken latch)—both of which can trigger a Bosch’s red flashing light.

Empty Rinse Aid Container

Rinse aid reduces the surface tension of water, allowing water droplets to slide off easily from your dishes. Modern dishwashers have rinse aid containers that need to be refilled if the rinse option is chosen. Before your dishwasher does anything, it will check to see whether there is enough soap and/or rinse aid for the selected wash cycle. The red indicator light may start blinking if there isn’t enough rinse aid.

Solution: Refill the rinse aid container

Open the dishwasher door and refill the rinse aid container. Make sure to fill it up all the way or to use as much rinse aid as you need for the cycle. Any amount of rinse aid should trigger the red light to stop blinking.

Not Enough Water

Dishwashers obviously need water to wash and rinse your dishes. If there isn’t enough water inside the dishwasher after waiting for a certain amount of time, the dishwasher may stop all operation and go on standby.

Solution: Check the water supply line

The first thing you should do is check the dishwasher’s water supply line to ensure it’s in place. Although you may not have moved your dishwasher in years, there’s a chance that the supply line could’ve been disconnected or possibly damaged, causing water to get all over your floors.

Another possible reason is that your water heater can’t heat enough water at the proper rate, making it impossible for your dishwasher to receive water. Make sure that the water heater is in working order and that it can supply enough water to all of your appliances.

If your water heater is working fine, you might have to shut off other water-dependent appliances. Doing so will focus water flow to your dishwasher, providing it with sufficient water before its built-in countdown timer expires.

Water Not Hot Enough

Bosch dishwashers heat water up to between 120 and 151°F, depending on the wash cycle. The sanitize add-on requires 151°F water, meaning that the built-in heating element should remain consistently hot for longer periods of time. The red light may begin flashing if the water isn’t hot enough after the heater’s timer expires.

Solution: Check the heating element

Checking the heating element in a Bosch dishwasher requires removing a panel to access the heat pump and timer. You can use a multimeter to check the pump for continuity, but there’s a greater chance that the heating element is on the fritz. You may need to replace it entirely¸, especially if your dishwasher is older than 5 years.

An alternate solution is to crank your water heater’s settings. The water heater will bring the water to a sanitizing temperature, so your dishwasher doesn’t have to. This, however, may increase your energy bill, so it’s highly advised that you repair your dishwasher’s heating element instead of toying around with your home’s water heating system.