Typical range is 65-75% of the maximum range due to terrain, weather, buildings, cables, hills/valleys, power lines, etc. If you are in a high-influence area, for example near big radio-emitters or high-power-lines, this can reduce greatly the range. The same can happen if you are on the top of a hill while your dog is in the valley, or vice versa.
If you are experiencing less than 50% range or if these environmental factors have been eliminated:
Try your trainer in a different area.
Replace the batteries, or if they are rechargeable, ensure the collar and transmitter are charged.
Ensure the remote transmitter and the collar are correctly synchronised.
If your remote has an antenna that can be screwed on, make sure it is tight.
Check batteries or check battery charge of collar and transmitter.
Check the stimulation on the collar with the test light tool (for collars with static stimulation).
Ensure proper collar fit. Place the receiver on dog's neck close to the ears. Fit should be snug, allowing 1 finger to fit between the end of the contact point and the dog's neck.
Make sure the collar is set to the right stimulation level or mode.
Make sure the transmitter is set to the right stimulation level or mode. Maybe a mode has been chosen for more than 1 dog, while you only have 1 dog/collar synchronised.
Increase the stimulation level. You can use the Boost button if your system has one.
Synchronise collar and transmitter if necessary.
Your dog may have become used to the stimulation. Stop using the collar for a few weeks, or switch to tone mode if your collar has this feature.
Make sure your dog is within range of the system. Test the system standing very close to your dog, then gradually increase the distance to find the system’s maximum range in that location.
If your dog is not responding but the collar is working, repeat training steps. Some dogs benefit from an occasional reminder lesson.
If there was a specific incident when your dog failed to respond to the trainer, consider the situation. Was there a distraction, such as a rabbit running by or a barking dog? You might need to use a higher level of stimulation in these cases, and you can use lower levels when your dog is more relaxed or less distracted.
For collars with static stimulation
Make sure the contact probes are making skin contact. This is where the static stimulation is delivered.
Trim your dog's fur where the contact points touch the neck. Do not shave your dog’s fur.
Purchase long contact points or use the ones included with your system if applicable.