Slow Bathroom and Cistern Cold Water Fill Drainage and wastage systems and plumbing help, advice and answers

[LizzieAnn]

Hi all, just joined. We are having trouble just since yesterday, with slow filling of our cistern - almost non-existent - and even slower cold tap running in our bath and sink upstairs in our bathroom, and we don't know why. We are currently trying to drain all the water down and restart in an effort to remove what we think might be an airlock in the pipes.....downstairs are absolutely fine.....any suggestions as to how long this takes please? We have a three bedroomed house and a cold upstairs loft tank and hot tank in son's bedroom. Urgent advice needed please!