YouTube video. Saw this and felt for the guy.

[Scott_D]

There is a woman taking a shower and it’s back feeding
Buts it’s a combi and must be off for him to be working on it.
How is the shower working?

 

[Burger]

No valve on the hot

But I thought I heard him say he’d isolated the cold? Which feeds the hot. Unless a botch plumbing setup?

 

[ShaunCorbs]

But I thought I heard him say he’d isolated the cold? Which feeds the hot. Unless a botch plumbing setup?

But didn’t turn the mains water off so cold shower which back feed the boiler

 

[ShaunCorbs]

There is a woman taking a shower and it’s back feeding
Buts it’s a combi and must be off for him to be working on it.
How is the shower working?

Cold shower

 

[Burger]

But didn’t turn the mains water off so cold shower which back feed the boiler

Ah, elementary @ShaunCorbs

 

[sammathias]

I was going to say it's fake as he can easily isolate under the boiler... But the read Shaun's comment and course it's back feeding from the hot!! Unlucky!