On 19/10/10 21:25, ARWadsworth wrote:
Tim wrote:
On 19/10/10 20:37, Andy Champ wrote:
On 19/10/2010 17:16, Tabby wrote:

How is a non-flammable metal/sand heating element in an enclosed
steel space going to catch fire?


Presumably the element is at the bottom of the oil container, so the
heat is carried away by rising hot oil.

As the oil level drops it will cease to circulate, the element now
being near the top of the remaining oil.

The oil nearest the element will now receive the entire element
output. Do not leave it unattended!

Andy

None of this would be a problem if regulations required:

a) High temp thermal fuse fixed to the element at the highest point
(ie lack of oil detector)

b) Lower temp (just under the boiling point of the oil) thermal fuse
in the oil close to the element.

That would constitute enough failsafes for me to feel happy. Alas
sometimes you're lucky if you get any thermal fuses - or if you do,
that they've been sensibly placed.

What! And end up paying more than £30 for a rad because of the cost of these
safety devices?

At least you will be warm as you watch the house burn down:-)


:-

Yes - the 30 quid fan heaters from Argos were good value - they fried
after one year, for the reasons previously mentioned... Despite being
run on a hard floor, not carpet. One melted a hole right through the
plastic!

At least the rather more expensive oil rads I got shouldn't do that, and
will find a second home in the workshop to be once I eventually get CH.

I know that was toungue in cheek - but for the nay-sayers (if any):

http://www.rapidonline.com/Electroni...ource=googleps

(In short - thermal fuses with various operating temps, 10A max normal
operating current, wait for it...

42p+VAT each...