I have a condensing boiler with a bout 1 foot of condensate pipe
outside going in to the stack. This has frozen several times and I
have now defrosted it and lagged the pipe and all has been well for 24
hours. However, i was wondering whether a couple of teaspoonfuls of
salt in the condensate trap might provide further protection. Or will
this damage the boiler?

Many thanks

Jonathan

Jonathan wrote:

I have a condensing boiler with a bout 1 foot of condensate pipe
outside going in to the stack. This has frozen several times and I
have now defrosted it and lagged the pipe and all has been well for 24
hours. However, i was wondering whether a couple of teaspoonfuls of
salt in the condensate trap might provide further protection. Or will
this damage the boiler?

I don't know about damage, but it would not help.

If the boiler has a condensate reservoir which is dumped out when full,
the salt would just get flushed out of the trap the first time. Even if
it doesn't have a reservoir and just drip-feeds condensate into the trap,
it wouldn't be long before your salt is all used up.

What you need is electric pipe-warming tape around the condensate pipe,
before you put the lagging on. But better still would be to plumb the
pipe to some drain inside the house, not outside. Or improvise with a
bucket temporarily.