Rust Coloured water from unvented cylinder's

[mas constructio]

Hello,

I have a question about a job im on, there seems to be alot of rust coloured water from the hot water feeds only , in a B+B i was asked to look at.
There is 2 phoenix unvented cylinders working the system.
One cylinder seams to have the hot outlet going into feed the next cylinder,
is that comon practise?
Why is there rust?
Tried to turn off one cylinder to see is it just one cylinder acting up or both, but because one feeds the other im finding it hard to narrow down.

any help much appricated, and thanks in advance.

Paul.

 

[prs1]

Is the first cylinder solar assisted, thats the only time ive seen unvented set up like that.
Could be the primary coil passing water from heating to dhw.
I take it the incoming main isclear?
seen very old systems linked this way but only once or twice,not common at all.

 

[mas constructio]

Hello thanks for reply,
The incoming water is perfect, as is the cold feeds that go'es to the bathrooms etc..
It has no solar heating it.
My first tought was a leaking coil, but there seens to be alot of rust, if i ran the tap for 30 mins it would still be dis-coloured....
I have isolated the heating feed to see if the pressure drops, if it does i then still need to prove that its leaking in the coil..
It has a pumped secondary return ( if that helps )
If the coil was leaking would there be so much rust?

Many thanks

 

[prs1]

If both cylinders are supplying whole b&b with dhw they should be fitted in parralell.
Does sec rtn go into cold feed if so i might be sediment in pipework asuming they are new cylinders on old pipework.
check to see if heating system is losing pressure or see if f & e is running constant.
Sound like a bit of a ball up but hard to say without seeing it.
Good luck and let us know how u get on with it.

 

[unguided1]

Is the secondary return pump, a bronze pump or has someone installed an ordinary heating pump?

 

[stevetheplumber]

if it been recently fitted on old barrel pipework its possibly the main scouring the old pipeworkof all the debris from the last 50 years

 

[mas constructio]

hello and many thanks for reply,

the system is an old existing system, brass pump , and the system just started to show the rust recently, it was perfect till then.