On Sat, 4 Dec 2010 07:15:31 -0800 (PST), gareth2701 wrote:

Make sure the condensate pipe slopes downwards at all points. The
heating engineer told me this - he reckoned that a large
proportion of
winter failures are due to pooled water freezing and blocking the

pipe.

That makes sense .

Pooled water won't help but the diameter of the pipe will. Any
condesate pipes that are external or in unheated areas should be 32mm
with a fall.

Mine slopes very well but it did not stop it

Some boilers just give a continuous slow dribble, this will freeze
and block a 22mm pipe quite quickly. Some boilers store the
condenstate in a small tank with an automatic siphon to empty it in a
whoosh. This is less likely to freeze and assuming the pipe as a
proper fall will tend to wash straight through as well.

--
Cheers Dave.
Nr Garrigill, Cumbria. 421m ASL.