# Cutting and rewiring thermometer/thermostat probes



## tomcannon (Jan 2, 2008)

Hello everybody! I have a quick question, I am hoping to extend the probes on my thermometers and possible on a thermostat. Is it possible for me to simply cut the wire and add an extension? Is it simply an electrical cable or something more complex?

Cheers, Tom.


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## my_shed (Jan 5, 2011)

I have done it to thermostat sensor cables in the past, i understand that since the sensor is resistance based this can lead to faulty readings, but since i check temps with a thermometer this doesn't seem to affect it anyways. Just set the thermostat as usual with the data from my thermometer. That said though, i wouldn't recommend it as it is increasing your risk of having thermostat problems and could endanger your pet. And it'll invalidate the warranty on you thermostat

Dave


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## tomcannon (Jan 2, 2008)

Ok, cheers for the reply. I may be able to get away without cutting the thermostat wire but the thermometer probes are certainly not long enough. Do you think they will be ok to cut and rewire? Or anybody else have any experience with this?


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## my_shed (Jan 5, 2011)

I would assume that these have a resistor based sensor too, therefore by extending the wire you would be increasing the resistance of the wire, which would give lower readings. This is based upon my (few years old) memories of electronics at GCSE, so please don't take it as gospel. Best way to work it out may be to line up 2 thermometers and check their readings, then extend one and check them again, that way you're already aware of any differences between them (one reads 24.6 and the other reads 24.9 for example) and then when extended if the difference between them is still the same (e.g. 23.2 and 23.5)

Hope this helps

Dave


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## tomcannon (Jan 2, 2008)

my_shed said:


> I would assume that these have a resistor based sensor too, therefore by extending the wire you would be increasing the resistance of the wire, which would give lower readings. This is based upon my (few years old) memories of electronics at GCSE, so please don't take it as gospel. Best way to work it out may be to line up 2 thermometers and check their readings, then extend one and check them again, that way you're already aware of any differences between them (one reads 24.6 and the other reads 24.9 for example) and then when extended if the difference between them is still the same (e.g. 23.2 and 23.5)
> 
> Hope this helps
> 
> Dave


Yeah I think that makes sense. That's a shame, I don't fancy inaccurate readings! Cheers for your help though. Much appreciated.


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## sam12345 (Dec 28, 2007)

How long do you need the wire to be. There a few places that do 2/3metre sensor cables on their thermometer.


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## markhill (Sep 22, 2006)

I'm sure if you PM Peterf he can make Habistats with longer cables.
He makes them with higher wattage ratings for people to order so I'm sure a bit of extra cable wont be too much.

Cutting the cables will invalidate any warranty.


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