The sprinkler is stuck or won’t return - The most common reason for this is water pressure that is too high or to low. Impact sprinklers can fail under either scenario. To determine what the operating pressure is, a pitot tube and a pressure gauge may be used to get a pressure reading at the head. This is done by placing the end of the pitot tube in the water stream, as close to the nozzle as possible. It is important to not place the end of the pitot tube inside of the nozzle opening. This can scratch the inner wall of the nozzle, as well as giving an inaccurate pressure reading. If the inner wall of the nozzle is scratched, the distribution pattern may be effected. Any of the previously mentioned problems can result in a non-rotating sprinkler.
The sprinkler is leaking - This is normally caused by worn washers and seals. They should be replaced at this time.
The sprinkler is not throwing as far as it should - This is usually caused by some type of blockage, either in the nozzle or the inlet screen. Cleaning the nozzle should be done with air, water or a soft bristled object (such as a pipe cleaner). Do not use wire or a screwdriver! This can scratch the nozzle.
The Maxi-Paw™ is a plastic impact rotor that operates in the same manner as other impacts. The Maxi-Paw™ does have one unique feature, and that is an arm spring that can be changed based on pressure requirements and nozzle size. It comes with the spring in the “A” position. The “A” position is the farthest notch from the counterweight end of the arm (refer to the figure below). This spring should stay in this position if using the 8, 10 or 12 regular nozzles, or the 10 low angle nozzle. The spring should be moved to the “B” position (refer to the figure below) when using the smaller nozzles. This is especially important when used in low pressure situations. Although this is an added feature, if the spring is in the wrong position the Maxi-Paw™ will not trip properly.
To troubleshoot a Maxi-Paw™ sprinkler, follow the same procedures that would be used with any other impact.