On 2008-05-28 20:35:28 +0100, Mark said:


Thanks for all the replies. I have looked at hiring a power flusher
but the only one I can find is about £100 and it doesn't mention use
in a sealed system.

Yes it will work with a sealed system. £100 is a reasonable price.

In the end, this is like a maintenance arrangement and insurance policy.

I've described what I would do given what you have. I would be very
confident, after this, having spent about £50 on chemicals plus some
moving of radiators outside for cleaning, that I would have a very
solid system that wlll last for 3 decades or more apart from moving
parts and the boiler. I could complete this work in half a day and
at my time cost of £50/hr, I will have spent £250 in cash and
equivalents.

For convenience, I could have chosen the power flusher followed by the
chemicals and spent £150 plus £200 in time .

I could have used the chemicals only and saved some work. Cost in
materials £50, £50 in time, but sludge not removed.

I could have bought cheap generic chemicals for £20. You have seen the
effect (or lack of efect) of these.


However....

The cost of replacing a complete system is in the £2000 - 4000 range.

Using the first option of £250 in cash and equivalents plus £20 every
2-3 years for inhibitor is a very good insurance policy.

It;s a job that is worth doing properly.