water ?

Carver Crystal Water flow not working properly.
Connection: Operated by Whale pressure switch in the cold IN feed, so no tap microswitches.
External.
Fittited pump to housing.
Lowered pump into barrel.
Gently bounced pump to expel any air as instructions.
Inside:
Switched on pump switch on control panel turned on cold tap pump engages and gurggles from tap and finaly water from tap steady but trickle flow. No more air.
Turned off cold and turned on hot.
Fair spurt to start some gurggling and slow flow worse than cold.
No signs or indications of air.
Question is is their a non return valve in the pressure switch ?
Is their a non return valve at the inlet end of the crystal filter housing the blue pipe is connected to?. I don't want to dismantle for nothing.
The pump pressure is good with following test
pump on slowly released the large filter in the housing and at leak point got soaked by extremely powerful spray (for a small pump).


Any ideas why the flow to taps is so slow?
Had taps out and washers ok (similar to house mixer taps). Another one is the pressure switch adjusted when cold taps turned on then off pump shuts off after 3 secs. the hot tap runs on for 25 seconds when I get this time short the cold taps stops working. Its a real, real pain in the BUTT.
The only filter I see in the sytem is the external carbon barrel filter.
Many thanks in anticipation.