Power shower running dry

[ross94]

Hi all, i have just replaced the bathtaps so obviously had to turn off the water at the cold water tank in the attic, one thing concerning me is the power showers. On turning the water back on,the bath taps work fine with no issues, but when i turned on both power showers in the bathroom and on suite they were extremely loud (a lot louder than usual) i immediately turned off both showers at their fcu's as i figured they were running dry as the water in the pipes have not reached them yet. the issue is with no power to the showers they will not allow the water to flow.
My question is how quickly will a pump be damaged if it runs dry? Both showers are mira vigours.
Cheers

 

[Stadan20]

You could just put the shower head down to the lowest level . Turn power off to pumps and operate the shower . This should push the water through by gravity . Leave running for a few minutes then turn power on to pump . Should sort it