Mixer Shower Slow Flow on Cold Feed

[jam00]

HI All

I fitted a new manual mixer shower , the cold feed comes for the water tank in the loft, I also fitted a full bore valve on the pipe but the cold is running slower than before I fitted the full bore valve (the hot water is running fine)making the shower slow, due to me having to drain the pipes out when fitting the valve could there still be trapped air in the pipe even after a month.

The cold water pipe runs comes from the water tank then running flat along the loft floor for around two metres

Many Thanks

 

[seco services]

could be trapped air or crud gone down into the filter.
have you tried it with the head off and hose lowered down and fully on cold ?

 

[FoxtrotOscar]

Is there a shower pump? If so where is it?

Check the valve is fully open in the open position, maybe it's faulty.

My bet is an installation issue of some kind, very unlikely to have air trapped in the cold pipe if it just runs from your loft to the airing cupboard.

 

[jam00]

HI

No shower pump , if it was an air lock what would be the best way to clear the lock out of the cold water pipe its fed from the water tank in the loft.

Many Thanks