Yes, it will. An electric heater can affect the PM2.5 indicator on the Xiaomi Smart Pet Care Air Purifier. Electric heaters work by circulating the air in the room and increasing the temperature, which can also make the air drier. As the air becomes drier, smaller particles, including dust and other pollutants, become airborne and spread throughout the room. This increase in airborne particles can lead to higher readings on the purifier's particle sensor.
Additionally, the dry air can cause dust to become more easily suspended, further contributing to elevated PM2.5 levels. It's important to note that this is a natural effect of heating and air circulation and does not indicate a problem with the air purifier's functionality. After a while, the readings can stabilize as the air conditions return to normal.