The MACH V1 Ultra adopts the cordless SteamWave™ technology, which dissolves tough stains on hard floors and removes them with ease by spraying a constant stream at 230°F (110°C), and at the same time gets rid of 99.9% of household bacteria. Please note that steam mode cannot be activated when the water level is low in the clean water tank or the steam reset button is popped up.

If the MACH V1 Ultra cannot activate the steam mode, please try the following troubleshooting steps to verify if the issue can be resolved:

1. Check if the clean water tank has a low water level. If necessary, please fill the clean water tank with cold tap water.
2. Verify the rubber cover is installed properly by opening the rubber cover and then fully pressing it down. Please note that the surface of the clean water tank should be smooth if the rubber cover is completely sealed.

3. Check if the vacuum cleaner's LCD screen displays a reminder that shows the steam reset button is popped up. If the steam reset button is popped up, please try the following steps:

• Press and hold the power button to power off the MACH V1 Ultra, and leave it powered off for more than 30 minutes.
• Remove the roller brush cover, and then use a pen to press the steam reset button down.

• Fill the clean water tank with cold tap water but do not exceed the MAX mark, and then pour an entire bag of citric acid into the clean water tank to enable the descaling mode. Please refer to the following article for detailed instructions on the descaling process: How to Enable the Descaling Mode for the MACH V1 Ultra 
• After the vacuum cleaner completes the descaling process, please run the vacuum cleaner in the smart mode for a few minutes.
• After running the vacuum cleaner in the smart mode for a few minutes, please fill the clean water tank with cold tap water but do not exceed the MAX mark and switch the mode to steam mode, wait for the red steam status light to begin pulsing, and then press the trigger on the vacuum cleaner to verify if steam can be released from the vacuum cleaner.