On 18/02/2020 13:08, Brian Reay wrote:
On 18/02/2020 12:39, Jim GM4DHJ ... wrote:
why does raw butane set off an ionising smoke detector ?

I'd be surprised (and worried) if it got near to one. Butane is denser
than air and tends to 'settle' near the floor. If there is enough in the
room that it reaches the smoke detector (which is normally mounted high
up), there is a LOT of Butane around.

I assume this is in your caravan? You should have 'vents' in the floor,
especially where there is Butane equipment (ie possible leaks). The idea
is, any Butane which has leaked 'sinks' out of the vents.Â* That is why
LPG and Boats can be a problem- you can't have vents! Boats should have
LPG detectors but I'm not sure how they work.


Yes it was last year at the van and the smoke alarms kept going off when
the cabinet heater was not on...never had any trouble before or
since.....I blamed a faulty outlet valve on the bottle.....didn't smell
any gas so I just assumed that a very small amount can set of an
ionising detector...was wondering if others had expeienced this...and as
you say butane and propane sinks to the ground and that is why they are
banned in high flats for obvious reasons......anyway a good few weeks
ago I bought a small 15kg flogas bottle and left it out the back door
when I went to use it the bottle felt very light and in the shack
cabinet heater it has only lasted a quarter of the time I would have
expected....so I am assuming another faulty valve on the bottle?..twenty
quids worth of gas wasted....so....I am now manually triggering the
valve on any bottles now and again that I buy and was thinking about
sticking a baloon over the bottle outlet to act as a tell tale for leaks
while in storage outside ......