DIY Doctor

Main navigation

Cold Water getting into hot water feed after new boiler install

Postby mike53 » Wed Dec 08, 2021 1:13 pm


Cold water is getting into our hot water feed, just had a new boiler put in and noticed the water temp had dropped a lot, especially upstairs, the installer checked and the boilers running fine and installed correctly. He switch off the feed from the boiler but we still got cold water from the tap, he thinks their must be a cold water line incorrectly connected to the hot line, said our old boiler must have been running very hot and maybe masked the problem. Does anyone seen this issue before? Someone also said it could be a problem with one of the shower mixer units allowing cold water back into the hot line.
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Wed Dec 08, 2021 1:03 pm


Simply Build It

Postby stoneyboy » Thu Dec 09, 2021 10:43 pm

Hi mike53,
You will need to check every fitting that has hot and cold water feeding it. Turn off the cold feed to each fitting while the boiler hot feed is off and you should be able to isolate the problem.
Regards S
Rank: Project Manager
Posts: 5084
Joined: Wed Dec 10, 2008 6:44 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics