Trouble climbing walls

If the pool’s water level is not the issue, sometimes the resolution to this problem can be as simple as ensuring the pool water is not too cold. For pool cleaners to operate properly, the water needs to be at least 10 C (50 F), depending on the model. Water can also get into the handle, which may cause the unit’s brushes to lift off the wall, causing the cleaner to fall off.
In this case, the handle may need to be replaced. Further, if the temperature is above 10 C (50 F) and the handle does not have water in it, then there might be a chance that the pump motor or propeller is defective. If this is the case, the unit will likely shutdown early because the pump motor needs to be replaced. On units where the handle is made to be set diagonally across the top of the cleaner, this positioning is important in order for the cleaner to traverse the waterline properly.
A dirty debris bag or chamber can also cause this problem. Automatic/robotic cleaners rely on water flow; if water flow in the cleaner is interrupted (e.g. because of a dirty water bag), then the cleaner will even have trouble getting out of a pool hopper.
The type of pool can also affect the unit’s ability to climb walls. In fact, fibreglass pools are by far the most challenging; therefore, look for automatic/robotic cleaners that use PVA brushes, which can help overcome this problem. Floatation devices can also be added to some cleaners to counter any slipping that might occur in a fibreglass pool.
In addition to challenging pool walls, professionals are now cleaning pools with many more obstacles built within them—from steps and sun ledges to seats and tables. Generally, these obstacles are located on either end of the pool, but primarily in the shallow end. Therefore, as a rule of thumb, it is best to start the robotic cleaner in the middle of the length of the pool to ensure the cleaner gets off to a good start.
At a standstill
Although it may seem obvious, the first step in this scenario is to make sure the power supply is properly connected to the outlet. If the unit moves in short, jerky motions it could have a deteriorated drive belt motor. Replacing the drive belt may solve this problem. Dirt could also be stuck in the drive pulleys; therefore, inspect for and remove any debris and then restart the unit. If the unit’s pulley teeth are filled with debris or missing, replacing the pulley is another option.
It is also important to check for wear and tear on the brushes and drive tracks, which can also become worn with everyday use and, as a result, may need to be replaced.
If the problem still occurs, and the unit uses a bottom-access bag cleaner, check to see if the bottom lid assembly is secured, as it could be dragging on the pool floor, causing irregular movements. To fix this, simply turn the pool cleaner over and secure the lid. In a worst case scenario, the unit’s bottom lid assembly may need new lock tabs.
Finally, many problems are created by pool owners who often try to operate their automatic/robotic cleaner using an extension cord. In this case, it is important for users to review the manufacturer’s recommendations when it comes to supplying power to the unit.