Plumbings gone doolally

[mrbios]

I'm not sure what happened but yesterday there were people from severn trent working on the water pipes out in the street, since they did something we had some crazy sounds come from our pipes followed by a water flowing at incredibly high pressure upon switching the taps on a small amount (only the first time, not recurring)

Thought everything was normal after that but last night we noticed that our upstairs toilet cistern is now leaking when we flush it (out of the top around the edge of the cistern top...not overflowing though!). Although I've not tested it it seems as though water is either flowing so fast that it's splashing back and hitting the top of the cistern...or the water is spraying upwards in that cistern.

Then today i've found the strangest part.....the downstairs toilets pipes have switched around. Cold is now coming out the hot pipe and hot is coming out the cold pipe, subsequently the cistern in that toilet now fills up with hot water!!

Any ideas what the hell has happened here?

 

[mrbios]

I cannot consider any scenario where external works can cause your hot and cold pipes to swap. How certain are you that this has not always been the case?

Certain that its never been this way before.

The kitchen taps, upstairs bathroom taps, bath and toilet are all completely normal. It's just the downstairs toilet + sink, which are newer than the rest of the house and in turn the newest plumbing if that matters.

 

[mrbios]

Water pressure seems to be a lot higher after testing the bath tap, might try turning the main valve down a tad and see if that solves anything.

Tested the cistern upstairs and its leaking because the pipe comes up the bottom and through the fitting, then spurts out the top of some random hole which I'm sure is meant to be facing downwards. Maybe it's always done this but hasn't been an issue becuase the water pressure wasn't always that high....the pipes also make a very strange rumbling sound when the cistern refills too.