Sludge in brand new central heating system

[avril123]

Can someone please help. We have had a new central heating system fitted including
new combination boiler, new pipes and new radiators.

WE are now finding black sludge is building up on the magnetron very quickly (after a week)
and is damaging the heat exchanger. Nobody has any idea why and everybody is suggesting
different things. The installers are saying it must be a faulty radiator and I am not sure what
to do now. Hope this makes sense.

Any advice would be gratefully accepted and acted upon. Thanks

 

[Millsy 82]

I take it it was flushed through corectley after install and inhibitor added

 

[Simon F]

Hello Avril,
was the system properly flushed, and refilled with inhibitor?

 

[avril123]

Nt sure. Know the system was flushed because of this problem so the inhibitor was probably flushed out. Do you think I should put more inhibitor in?? Would this solve the problem? Still confused as to what is causing black sludge

Thanks for replies

 

[scoullar]

you will always get a slugde build up even with inhibitor just make sure you have the right amount in for your size of system i would recomend a powerflush and start again

 

[Simon F]

the purpose of flushing a new system is to remove any flux, wire wool etc left in the pipes during fitting.
flux is acidic and will speed up corrosion in the system. there are chemicals to put into a new system to help this process.
when the system is cleaned then inhibitor is added to try and prevent corrosion.
if these things were not done or done badly, this could be the problem.

If its a new system, I would be expecting the installer to resolve the problem,
you mentioned a week, is that how long has the system been fitted?

 

[dancinplumba]

initially you will get sludge, but as the oxygen is depleted from your system water, this will diminish. as long as you are not topping system up regularly with fresh oxygenated water, things will be fine.
you have a filter (magnetron ?) this should trap magnetic particles and some non-magnetic, which will stop them going to your boiler heat exchanger/pump if it's on the return pipe
imo

 

[avril123]

Thanks for all your replies. The system has been installed about a year and we had to have a new heat exchanger as we did not know this sludge was building up. NOw we have to take the top off the magnetron and wipe it as so much sludge is appearing. The installer says he does not know why this sludge is appearing. Do you think taking radiators off individually and flushing them through would help?

 

[M.Joshi]

Cheap radiators?

Do you find that you have to frequently re-pressurise the system with the filling loop?

 

[hammers4spanner]

New central heating,,did you have any prior??
Possible if you did the installer took short cut and left alot of pipework in from original system??

 

[FD Powerflow]

If your installer didnt flush out the system when he installed it then chances are there is still flux left in. If that was the case then it wouldnt matter how much inhibitor you put in, the flux would steadily attack any metal it could, usually kills aluminium (heat exchanger) first. Black magnetite is a result of corrosion that has finished taking place.

Your solution is to add Fernox F3 cleaner into your filter, run the system for at least an hour and he dropping the sludge out until it starts running clear. I would leave that cleaner in for the rest of the week and clean the filter again. Once the filter is running clear you will then need to drain down the system (to get rid of the flux and Cleaner) then you need to refill with fresh water and add F1 Protector (other brands are available) this will stop your system from further corrosion.