Heater goes haywire

Like I posted in a previous post. The price of a simple electronic
temp controller is dirt cheap compared to whata prices we pay for the
critters in our tanks, and a well made reliable unit can be had for
about $105 from Aquatic Eco Systems in Florida. Lacking the funds to
buy the temp controller, its best to divide the required heater
wattage amount in half and use two heaters to achieve the needed
wattage, as this will reduce or at least delay overheating and also
help with allowing a tank to get too cold if one of th eheaters
happens to fail.

An alarm is nice, as is a gen set in power outages, but it does
little good if your not there when it activates or the power goes off!
;-)


Its thematerials they make the bi metal switch out of. They use IIRC
positive co-efficient materials as they are cheaper, and requires less
parts etc to make it work. We had temp controls on aircraft that used
negative coefficient parts and they were about 4 times the price of
what a positive coefficient unit was. Last thing you would want is the
aircraft heater to stick on in a sinfle seat fighter aircraft ;-) YOu
can always drop down in altitude and point canonpy to sun to warm up a
bit, but cooling down is much harder to do when oiy have 1100 deg
bleed air pouring into thatsmall cockpit space.... I guess thats why
we only pay about $20 bucks for a name brand heater in most cases.....


On Tue, 13 Feb 2007 01:38:22 GMT, Wayne Sallee
wrote:

Also if you see condensation in the heater, then
it's time to change it. Moisture will cause
corrosions of the electrical contacts. and the
corrosion will cause them to stick.

Wayne Sallee
Wayne's Pets


KurtG wrote on 2/1/2007 10:46 PM:

I just pulled a heater out of my sump. It was 82.8 and it was still
heating.

How often do these go haywire? There seems to be lots of stories of run
away devices. You'd think they could design them to fail by turning off
rather then on.

I certainly like my digital thermometer w/ an alarm. I think it just
earned the $10 I spent on it.

--Kurt



-------
I forgot more about ponds and koi than I'll ever know!