Power or chemical flush?

[Madmog]

I'm about to have a new combi boiler installed on a system which is 12 years old. as far as I'm aware an inhibitor has never been used on the system. When the expansion vessel was replaced 3 years ago the water was black, almost oily.

Any thoughts on whether a chemical clean or power flush would be best. £290 for power flush, but after having eight breakdowns in twelve years happy to pay if it might reduce future problems.

Also is Fernox can worth fitting on the system, how often does it need changing?

 

[Whitespirit66]

12 years. No inhibitor. I think you know the answer.

Powerflush.

Hope your rads are up to it.

Perhaps you didn't realise, but ch systems need inhibitor like cars need antifreeze. Putting the odd bottle in every few years would poss have saved the cost of a power flush and breakdowns on a youngish system.

 

[Madmog]

Thanks - yes, we've learnt a lot in the last few days. The engineer we've used for nine years perhaps wasn't as good as we thought.