Dripping single lever basin tap only when shower mixer is turned off

[flatiron]

Hi everyone,

I recently had a Hansgrohe wall mounted single lever basin tap and a Hansgrohe thermostatic concealed bath/shower valve installed (full bathroom renovation). The basin tap started dripping a few days after installation. But it stops dripping only when shower is turned on. Any ideas on what could be wrong?

 

[exedon2]

If your lucky cartridge in tap may need cleaning if it's been scratched internally may need replacing.
It stops dripping when shower in use due to reduced pressure.

 

[flatiron]

If your lucky cartridge in tap may need cleaning if it's been scratched internally may need replacing.
It stops dripping when shower in use due to reduced pressure.

Thanks for responding. How do I know if cartridge has been scratched? It's a Hansgrohe Basic Set for mixer tap for concealed installation and has only just been installed.

I noticed that the tap stopped dripping after the shower had been turned on a couple of times. I will see if it starts to drip again. I think it may have started dripping after the basin tap had been turned on for hot water to run out of it.

 

[exedon2]

If you take it out clean it and it still drips probably needs new cartridge.
Unfortunately ceramic disk taps are not guaranteed against 'water borne debris'.
That includes hard water.
New pipework should be carefully installed and flushed out.