This issue usually happens when the vacuum was not charged normally, the vacuum is clogged, or the filter is not clean/dry. 

1. Please confirm if the H30 gives one of the following indicators:

A. Solid red indicator: Confirm if the vacuum had sucked liquids or was used without filters.

B. Flashing blue indicator: Fully charge the vacuum to see if it resolves the issue. Refer to: What to do if HomeVac H30 cannot be charged?

C. Flashing red and white indicator alternatively:

- Whether the roller brush of the Pet Motorized Brush is clogged by debris like hair, etc. Clean and see if it works.

- Confirm if the dust bin is full or needs to be cleaned. 

- Confirm if you have cleaned the filter and whether it is completely dry.

2. If there's no error indicator but the vacuum cannot be turned on to work, confirm if the vacuum was working in an environment with a temperature range of 0 to 40 degrees Celsius. 
3.