You need to call a Corgi boiler engineer for this one. This model has a hot water calorifer (like a mini cylinder). When the system was flushed, the inner coil has perforatted allowing a cross of central heating to domestic hot water. This is not necessary the flush that caused it, it just may have shown it. Some flushing chemicals are acid based, for speed, and may have enlarged a small hole previously blocked by the same sludge you wanted to remove.
Repair is not cheap and is fiddly so expect at least three hours labour plus parts.
Your boiler is no spring chicken, so a replacement may be in you long term interest. Get at least three quotes!
Finally, check that the inhibitor added is not toxic, but nowadays most are not.
Bad news I know but I hope this helps
Andy Shotton
March 2008
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