Stand alone doser issue

[BrklynArch]

My doser recently started giving me some weird problems with pump 1.
Pump 1 will activate and rotate but it doesn't draw in any liquid.
It started 2 weeks ago when I noticed my Alk was way low. Come to find out the doser hasn't been dosing any for days.
I checked the connection to the vessel it was drawing from swapped out tubes even cleaned the lines and motor.
After cleaning and reassembly it bagged working for about a week...then a few nights ago I notice it's doing the same thing.
The other 2 pumps work fine btw....
Any suggestions? The doser was bought new from aqua cave @ 2 years ago not sure if the warranty is still good.
Any help would b appreciated
Thanks

 

[Antipodes]

Check the actual tube in the doser to see if it may have a small split. Or it may just be getting to hard. Hose should be cheap enough to just replace?
They are a pretty reliable pump, and my 4 pump unit has been going for 4 years without issue.

 

[BrklynArch]

Check the actual tube in the doser to see if it may have a small split. Or it may just be getting to hard. Hose should be cheap enough to just replace?
They are a pretty reliable pump, and my 4 pump unit has been going for 4 years without issue.

I thought i had cleaned it well enough last time, but ill give it another go tonight when i get home.
worse case scenario i have Pump 3 available so i can just pop the Alk feed lines onto that pump in the mean time.

 

[AQD_ottawa]

Few tips here as a general note

electronics have 2 year warranty
motors 1 year.
Peri tube/pump - no real warranty as a degenerative/service item unless faulty on receipt.

Servicing should be performed every 3 months as a rule, this involves removing the pump, cleaning the inside of the pump out and re-assembly, do not use any lubicant.

The tube should be replaced every 6 months.

if the pump after two years is not drawing, this points to the pump slipping on the motor shaft due to a very worn out peri tube binding or worst case if not serviced the motor starts to slip on the pump rollers and in long term wearing the rollers out until no further grip is possible.

Dosing pumps are a work horse and require servicing, if serviced they will go on trouble free for years, more so GHL units built to last for a life time

Hope this helps.