Brown central heating water

[robj20]

What is the cause of brown central heating water?

Its a completely new system, plastic pipe throughout, expect first meter from boiler and the risers to the radiators.
X300 was flushed through first then filled with F1.
It has a filter on the return.

Been using it for about 2 weeks now and took one radiator off to decorate and found brown water.

 

[Last Plumber]

Brown tends to indicate rust.
Has it been flushed and treated correctly?
Do you know what dose of F1 was used and if it was correct?

 

[robj20]

Brown tends to indicate rust.
Has it been flushed and treated correctly?
Do you know what dose of F1 was used and if it was correct?

On the benchmark sheet it says flushed with x300 and inhibitor used F1, that's all I know.

Is it worth draining down and using something like x400 or is x300 better. I have a spare can of F1 that they left me as I said I was taking some radiators off soon be said to just put the can in the empty radiator before filling back up.

 

[Last Plumber]

How brown is it?
Are we talking slightly discoloured or muddy?

When you fill a new system with fresh oxygenated water, the mild steel radiators will be lightly coated with rust in a very short time. Was the system flushed and treated immediately or were there a few days of just water?

You could always get it hot, drop it out and re-fill and treat it with F1. Follow the instructions on the F1 for dose rate. Do you know the size of the Heating system, (I don't mean the Boiler output I mean the system output).?

 

[robj20]

Size wise it's got 7 radiators at the minute.
Its like coffee brown. It was left overnight but I don't know if that was worth the x300 or just water. The boiler was fitted in the space of two days.

I had the radiators fitted for a few weeks with the system empty. Can you put too much F1 in. Think the can says for systems up to 11 radiators.

 

[ShaunCorbs]

I normally use two bottles on a stnd house and no within reason you can't

 

[robj20]

Thanks I will stick two in them when I do a drain.
Now x300 or x400. Or just a plain water flush.

 

[Last Plumber]

Perhaps be best to get it hot, empty it completely, re-dose.

I would use a 500ml F1. (without seeing it).

You can overdose with Inhibitor but the issues it can cause are not the ones you describe. You would need to go way over the top too. You would struggle to overdose it by accident.

Is this a sealed system?

 

[robj20]

Yes sealed. Thanks for the help.

It's one of the F1 express bottles they put in. 265ml. So that's way off 1 liter.

Notice fernox do a Filter Fluid+ Protector 500ml, would it be worth using two of those. Seems to describe my issue.

 

[Last Plumber]

Yes sealed. Thanks for the help.

It's one of the F1 express bottles they put in. 265ml. So that's way off 1 liter.

Notice fernox do a Filter Fluid+ Protector 500ml, would it be worth using two of those. Seems to describe my issue.

Sorry, I have edited my post above. I was thinking 'little bottle'. I just double checked the size and the F1 I use are the 500 ml Protector F1. I would use one of those in your system.

 

[robj20]

So my plan is once i fit the radiator back on is to drain the system down and put a 500ml of Fernox F3 in the empty radiator. Run the system and run it through each radiator individually for a while then just run it as normal, probably keep an eye on the filter as well and flush that out if needed.

Then drain and refill with Fernox Filter Fluid+ Protector (seems to be F1 + something to keep particles suspended so they get trapped in the filter) probably put an extra 250ml of F1 in as well as the majority of my radiators are pretty big doubles so it takes me to 4 doubles and 3 singles, so counts as 11 radiators.

Hopefully the reason the one radiator was dirty was because when they used x300 they just ran the whole system so any radiators with low flow may not have had much benefit.