On 22/03/2018 09:20, David wrote:
On Thu, 22 Mar 2018 08:19:33 +0000, PeteFJ wrote:

I had my Worcester combi boiler serviced last week, and the engineer
suggested that the system needed flushing out as the water in the system
was discoloured.

I spoke to a local plumber who told me that it if was working, then
leave it alone. He added that his policy was to leave well alone.
I might add that the boiler is working well.

So, as a consumer and householder with no technical knowledge what
should I do?

Thank you,
pfj

Could go either way.

If the water is badly discoloured then the insides of the radiators are
probably rusting - that gives a black colour to the water.

The question then is has the water used up all the oxygen and so not able
to rust any more, or is there oxygen getting in and more rusting taking
place.

I assume that you have inhibitor in to reduce or stop internal rusting?

Things you could do.

Do nothing.

Add some inhibitor (helps if you know what type is already in).

Flush out the system (replace the current water with new) and add
inhibitor.

As all of the above but add a magnetic filter to the system. This should
in time remove the rust in the water (which makes it look dirty) but won't
address any corrosion issues.

How old are the radiators? See the thread just below about power flushing
if the radiators are old and have cold spots at the bottom in the middle.

Cheers



Dave R


How many times has the OP had to repressurise, which adds fresh
oxygenated water. ?.

If hardly ever, then all the O2 will have been used up, OTOH
if there was inhibitor, it needs to be replenished, so a drain
down and run with flushing cleaner, then redrain and adding new
inhibitor could extend its life.