Ian_m wrote:
"the_constructor" wrote in message
et...
The condensate pipe on my combi boiler comes out of the wall and rests
in the hopper of a downpipe but with this rather cold weather that we
have all been having, it has tended to freeze up quite a bit.

This got me to thinking.

The basin and bath waste pipes never seem to freeze up and these are
directly into the soil pipe. I assume, rightly or wrongly that this is
because (a) the ubends are inside the house and (b) because of the
gasses inside the soil pipe come up into the waste pipes.

Working on theory (b), would it help if I take the condensate pipe
from the hopper and feed it into the bath waste pipe using a 'T'
connection and reducing plug thereby keeping the open end out of
direct contact with the outside air. I have plenty of drop on the pipe
to do this, or should I lag the pipe, though I don't think lagging is
the answer.

Your thoughts as always would be most gratefully appreciated.

My boss had his condensing boiler switched back to a non-condensing, by
the boiler manufacturer, as the condensate pipe run kept on freezing,
despite being the pumped variety. The pipe would block, the boiler
flood, which would immediatly halt, but this repeated happening corroded
the inside of the boiler. Went through 3 boilers in 7 tears, all under
warranty, before switching to non condensing. Apparently a condensing
boiler should never have been fitted in this location, a detached'ish
garage, due to having have a long run of condensate drain pipe. One fix
tried was heat tape on the pipe, but as he found out that was disipating
100W 24/7 and was not pleased when this was discovered.....

Might have been simpler to put a thermostat on the heat tape so it was
only on in frosty conditions.