Where on earth is this brown water coming from?!

I was assuming the combi was closest to bathroom,& usually the first tap water is drawn from in the morning.
In the morning try the kitchen taps first & see if you get the brown water, might need to run it a while.

 

I'd check those short lengths/bends of copper you've put in for iron content!

You might first do that by poking a cloth down there to see if there is any corrosion.

Mr. HandyAndy - Really

 

As Mr H, all is not as it seems when it comes to certain stuff!, I use 4 pair BT cable in my game, I need full copper, I don't get it unless I ask/pay more.

 

OP
There must be iron particles held in the system local to those taps...and not being flushed out when water runs.
Is it possible to dis the piping from the taps and as far back as poss in bathroom...take outside and inspect..dis assemble flush. ?
RS

 

Just out of interest has you water main in the street been upgraded in the last few years or have you recently been fitted with a water meter.

 

Blimey. Iron pipes feeding the garden taps?

 

Twas a time DA, way back when Tom was a nipper that entire water systems were done in galvi pipes