tefen MixRite 2.5 - MixRite Does Not Draw Additive; MixRite Makes Scratching Noises; Water Flowing Back into Additive Container

Subject
Check
Solution
MixRite does not
draw additive.
The suction filter is blocked.
Clean the filter.
Dismantle the pump unit and
check if the suction seal is
defective.
Replace the suction seal.
The non-return valve is defective.
Replace the non-return
valve.
MixRite makes
scratching noises.
Check if there is liquid in the
additive container.
Add liquid to the container.
Check if the suction pipe is
immersed and not folded.
Straighten or change the
pipe.
Check suction filter to see if it is
blocked and if it is immersed in
the additive tank.
Clean and rinse suction
filter. Fill liquid into tank to
cover filter
Water flowing back
into additive
container.
Check valve.
Clean or replace the check
valve.