Guaranteed cleanliness?
Q. Can you guarantee to get a system clean with a
power flush?
A.
Although an engineer may power flush a system until
the water exiting the dump hose is clear, and will usually
carry out tests to check this, it is not uncommon for
a system with relatively clear water to still have some
compacted debris in the lower parts of the system /
radiators. This may later break loose and discolour the
water, although it is rare that it is in sufficient quantity to
cause problems.
Engineers occasionally find a layer of very hard black
iron oxide corrosion debris (magnetite) in the form of
scale on the internal surfaces of pipe work, and which has
developed over many years. Sometimes this hard scale
will not be removed by a power flush, but fortunately the
same adhesive nature that makes it difficult to remove
also tends to keep it bonded to the pipe where it does no
harm.
How long will a power flush last?
Q. Once I have a power flushed a house, will it require
flushing again after a few years?
A. We would not expect a well designed system without
obvious problems to require a further powerflush in less
than five years, and generally for much longer than that
if the system has been properly treated with a Buildcert
approved inhibitor. However, there are too many
variables and unknowns for us to give specific advice.
