source of metal chippings in central heating system?

[westbury16]

We installed a completely new central heating system just over a year ago. We have hardly had more than a few weeks at a time when the control valve has not clogged up with what are ferrous small metal chippings and dirt. My plumber installed a filter just before the return goes into the new Vaillant boiler. He says the metallic chippings must be coming from the Heat exchanger, since the way the flow works , they would be caught by the filter before they get into the boiler. The control valve is the first item the water gets to after leaving the boiler. Vaillant of course don't want to know. "Dirt in system - not ours" this is not dirt , it is ferrous chips, because they are magnetic.
Alternatively , could this stuff come of the inside of our new radiators?
Plumber has of course drained and refilled system twice. Before the summer he put inhibitor in the system , and come the winter when we switch on again, lo and behold, valve is clogged. Plumber cleaaned the valve and all works perfectly. That was three weeks ago, and now we can see that the rads are progressively not heating up as they do when valve is working and clean.

Anyone got any ideas as to a) what to do and b) where this stuff is coming from : heat exchanger or radiators??

 

[cowley]

Have a proper power flush done and fit a Magnaclean to system.

 

[westbury16]

Have a proper power flush done and fit a Magnaclean to system.

The advice is good , and I will do as suggested. But I am still curious to know if other people have this from new installations and is it a fault within the radiators or the Vaillant boiler heat exchanger.
Who should be paying for the additional work of Powerflush and installing the magnetic filter??

 

[DP]

If the metal particals started at the boiler, these would now be resident at the base of the rads.

New system, even brand new, have to be cleansed using chemicals to remove copper swarf, metal particles in radiators, flux, solder etc.

When you say system is brand new, do you mean the pipes, radiators, valves and boiler are all brand new i.e. no parts of old system retained? Is the pipe plastic?

 

[westbury16]

If the metal particals started at the boiler, these would now be resident at the base of the rads.

New system, even brand new, have to be cleansed using chemicals to remove copper swarf, metal particles in radiators, flux, solder etc.

When you say system is brand new, do you mean the pipes, radiators, valves and boiler are all brand new i.e. no parts of old system retained? Is the pipe plastic?

Yes , system is completely built from brand new everything. Installed summer 2008. Plastic piping. Radiators are the kind that have 'flat front that stays relatively cool. Vaillant ecoTec plus 637 boiler.
We have had nothing but trouble with this system since it was put in. What I want to know is it the rads or is it the boiler suppliers wha are responsible. Or is it my installer for not cleaning the system out properly. He says he's never seen this before and has been a builder/plumber for years . I have paid him- but I want to know if it right that he should be paying for the powerflush and filter..? Or should we be pursuing Vaillant ?

Thanks

 

[DP]

It is unlikely to be the boiler. Persuing Vaillant without foundation will be like pi55ing into the wind

Radiators- well hard to say but often times manufacturing debris needs to be removed when commissioning the system, else would 'hurt' the system

Plastic pipe. There is plastic pipe suitable for heating systems and then there is pipe that should not be used to carry water to rads. I choose to plumb in copper unless installation of copper not possible. Plastic pipe creates its own type of corrosion that can be a very effective plug to stop water flow.

 

[butchzak]

I also would not use plastic pipe in CH systems even if recommended. My understanding is that oxygen can still diffuse into the system and the manufacturers of this pipe now recommend triple strength inhibitors in such systems. The advice to fit a Magnaclean is sound, it's amazing what they collect.

 

[Onetap]

"Dirt in system - not ours" this is not dirt , it is ferrous chips, because they are magnetic.

They are most likely from the radiators, probably swarf from cutting the screw threads on the connections. Tha Vaillant heat exchangers are stainless steel and may be non-magnetic; there are some magnetic stainless steels.

The system should have been flushed out on completion. The builder/plumber could carry out a power flush or he can make repeat visits to clean out the debris.

Check the markings on the plastic pipe to ensure it is barrier pipe. You will find the details on the manufacturer's website. If it does not have a barrier (to prevent oxygen entering the water) it is not suitable.

 

[tryitandsee]

I'm sure I'm picking up the wrong end of the stick here, but you have said 'dirt'. Has the plumber pushed long lenghts of pipework under the floor boards (ground floor) when fitting rad pipework, scooping up debris in an uncapped pipe end. Only takes 2 minutes to cap off end before pushing /pulling through but often done by the lad.

 

[mrgas]

Have you got any chrome plated steel towel radiators?
I have in the past found incredible amouts of metalic debris left in these rads by there manafactures.