Water pumps cycling!

[Eidr]

Hi all,

After a bit of advice, just replaced two Stuart Turner CFL 5.0bar single ended pumps with two new Stuart Turner Kennet KFL 10-2 pumps due to one of the original pumps failing. The flow switches on the pumps are linked across from one to another to enable both pumps to run with either hot or cold demand - in order to overcome problems associated with mixer taps.

My problem is, on the basin mixer to the ensuite and the basin mixer in the cloakroom the pumps will cycle on/off if only hot or cold is requested. if a mixture is requested then pumps will run correctly.

the bath mixers and basin taps (singles) in the other three bathrooms work fine.

The basin mixers with the problem are both Axor Stark mixers with the very thin european flexis connecting them to 15mm isolator valves.

My thinking is that these small bore flexy connectors could be the culprit. Does any body have any thoughts/advice/cures?

Your help is greatly appreciated.

Mark

 

[Eidr]

Just for info in case anybody encounters same problem. Went back to the job today and after checking pressures and flow rates to all outlets and out of all outlets, narrowed problem down to the 'non drip' valves installed in the end of the Axor mixers spouts.

Removed 'non drip' valve, leaving only the aerator in spout and all works correctly with only 2 - 3 seconds of drippage after mixer closed.

Mark