intermittent brown water from hot tap

[Neil Carroll]

This morning I discovered that there was brown water coming from the hot tap only (all hot taps) , looks like the sort of thing you get when road works have taken place , however not the case as only the hot tap effected, this is obviously something to do with the boiler. Everything I have found online points to the inside of the combi rusting.

I have a few queries however.

The water sometimes runs clean for 15 minutes then gets bad again?
Also I havent noticed anything in the past, its gone from clear to brown ,
We have a white bathroom suite so it would have been noticible.

Does this sound like the inside of the boiler rusting?

Ther boiler is approx 10 years old

Thanks in advance ,

Ps , water doesnt smell bad.

 

[oldbuffer]

1. What boiler (make and model) is it?
2. Are you sure its a combi?
3. How brown is the water:
3a. If its very light brown, AND
3b. You do have a combi boiler THEN
3c. Its possible there is a leak in the secondary heat exchanger, allowing water from the heating system to contaminate the hot water.
3d. The heating system should contain inhibitor, which is a light brown in colour.
3e. Also the radiators are steel, and can rust, particularly if there is no inhibitor in the system.

 

[Roddy Young]

You probably have an unvented cylinder with expansion vessel.

It is possible you have a leak in the expansion vessel diaphragm, allowing the water to reach the steel surface and pick up rust with its colour.

That happened to us and the bath water looked very yellow/brown (before I even got in.....)

 

[Neil Carroll]

boiler make and model is ferroli optima 901 (yeah i know !!)
is a combi , water is yellow , another forum suggested that as the pressure on the boiler hadnt changed that theres a possibility that its not the heat exchanger and possible a faulty filling loop? Also has only started since turned heading off (hot water only). I cant see how a faulty filling loop would effect anything , could it be pushing rad water into hot tap?

 

[Neil Carroll]

Roddy , Thanks for advice I will check that , did you get it replaced?

 

[Roddy Young]

Yes, I eventually found a stainless steel one which cost a bomb........ No problems since then.

 

[Neil Carroll]

would this explain the fact that is yellow/brown to begin with , then clears, then re occurs? , also did it start without warning
I appreciate your advice.

 

[Roddy Young]

I don't think it started suddenly - I had suspicions for a couple of weeks that something had changed in the water colour - how long that had been going on is impossible to guess.

After I noticed it, the effect was consistent, ie not re-occurring.

Initially, I assumed the water supply had been contaminated after heavy rain or something.

We live in a village and the water has been known to change colour occasionally.

 

[Neil Carroll]

Ok, I think its fixed , I looked at the filling loop again and the tap appeared damaged so it looks as if it has been costantly filling for I dont know how long ,
I Have replaced it and alls good , I was just wondering if anyone could explain what was actually happening , how could an open loop produce brown hot water ,
Thanks for all your help , I really appreciate it.