R. Cott. 24

How long had the boiler been in use? Was it installed into a well cleaned system? and what type of boiler is it?

Two to three years. Installed as an upgrade by B.Gas. Potterton precision. Condensing system boiler used on a conventional vented S plan radiator/cistern system.

System was said to be power flushed and they fitted a magnaclean filter. A finger down the output pipes finds the usual black residue on the walls.

Sounds like if the system is given a good flush prior to recommissioning the boiler it ought to be ok...

In message , John Rumm writes

None of the old system remains! Underfloor will be new pex-al-pex and the rest fresh copper.

Even less to worry about then... (although even a new system requires flushing just to remove any flux / particulates etc left from fitting).

There is some concern with things like rads that have been left dry for some time, since the will rust internally. But a modern boiler should have a corrosion resistant HE anyway.

Mum had some work done in her bathroom a while back that involved re-routing some of the CH / HW pipes between the wall mounted, low capacity, balanced flue boiler and the HW cylinder.

Some scale from the inside of the very old / ex gravity fed CH system must have got washed into the HE, causing it to over temp.

We drained the system (and flushed it several times), and removed the heat exchanger and flushed that though separately with a hose in the garden. There was remarkably little scale buildup in there [1], considering how long it had been up on the wall (and I think it was second hand when she got it years ago) but we may have seen a couple of bigger chunks of scale from the ~1-1/2" pipework that were cleared away.

It's been working fine again ever since. ;-)

Cheers, T i m

In message , T i m writes

On a closed system, the concern seems more related to iron oxide sludge from the old radiators. I can easily run the garden hose through it and perhaps try some flux cleaner as advised for the pipe flushing.

And the batteries?