You can add rinse aid along with detergent to your Bosch dishwasher to assure there are no spots on your dishes and that they dry properly. If you notice spots on your dishes or discern that the rinse aid is not dispensing, you may need to replace the entire dispenser.
Dispenser Door Inspection
Before you inspect any inner parts in your Bosch dishwasher the electrical power should be turned off from your kitchen circuit breaker. The rinse aid dispenser is located next to the detergent dispenser inside the door. You can check to make sure the dispenser door is not broken by opening and closing it. If the door to the rinse aid dispenser is broken then you can pry it off using a flat head screwdriver.
Front Panel Removal
To inspect the entire rinse aid part by itself, it must be fully removed from the dishwasher door. The front panel must be taken off the door first by removing the torx screw from the top inside of the door panel using a torx screwdriver. The door can then be shut, but it's important to not latch the door all the way. The front panel can then be lifted off of the door and set aside.
The back end of rinse aid dispenser is visible with the front panel removed. In order to take out the dispenser, the two screws holding in dispenser must be removed using a Phillips screwdriver. Then, the wire connector attached to dispenser must disconnected by pulling it out with your hand. The entire dispenser can then be lifted out of the dishwasher door, and you can set the part on a dry cloth in bright light in order to properly inspect it.
Damage to the part itself is typically visible, and you should look for cracks, holes or other types of damage that could cause it to not work properly. If you don't see any visible damage you should check the wire connector to make sure it is not broken and that it was properly connected to the dispenser. If the rinse aid dispenser still doesn't work after it's reconnected then you should get a replacement part.
New Part Replacement
If you need a replacement part, look for a customer service number in your Bosch dishwasher manual. You can also purchase a new part from an online retailer, such as Sears Direct, Repair Clinic and the official Bosch website. The new dispenser must be inserted back into the door and the wire and screws reinserted. You can the place the front panel back on, reinsert the screws from the top inside of the door and turn the electrical power back on from the circuit breaker.