# Don't trust my Thermostat..



## Matchoo93 (Aug 16, 2014)

Hey everyone, first post here 

I've just set up my viv for my Leopard Gecko, and I think there either may be something wrong with my Thermostat, or its rubbish.

Its a MicroClimate Ministat 100W, which I have set at 31 degrees C.

My problems are that it doesn't stop at 31, according to my Exo Terra Combometer which I have taped right next to the sensor, and when it does cut off, it takes ages to turn the heater back on, and can drop to around 27-28 degrees C.

I'm using a Habistat Heat Mat 40W, under my Exo Terra 90x45x45, with a thin layer of sand under my ceramic tiles.

Any suggestions?


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## reptiles-ink (Nov 4, 2006)

Put the thermostat sensor on the mat and the thermometer probe inside where you want to set the temperature.
Then adjust the thermostat going by what the thermometer says.
This should prevent such large temperature swings as well as overshooting.


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## Matchoo93 (Aug 16, 2014)

I can't really get it directly on the heat mat, but I've tried changing it using the thermometer as the reference rather than what's on the dial, and I'm struggling to get it 100%.

Its the drop off that concerns me really, so I've ordered a Habistat Pulse thermostat and going to return the microclimate as I'm not happy with it.


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## sharpstrain (May 24, 2008)

that is perfectly normal for an on off stat, a pulse will give different results


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## Paulington (Aug 14, 2014)

If the MiniStat is anything like a HabiStat Mat Stat, I wouldn't trust it as far as I could throw it.

What you are describing is normal behaviour for an on/off style mat stat, let's say you have it set to 31 Celsius, it will likely keep on heating until it's at, say, ~34 Celsius, then turn off and drop to around ~26 Celsius, turn on again and repeat. The reason it does this is to prevent it going 31 Celsius, off, 29 Celsius, on, 31 Celsius, off, 29 Celsius, on, repeat ad nauseum.

When my partner used a mat stat set to ~28 Celsius, I noticed that I could treat that as just an "above average" temperature, I averaged out the readings by the temperature probe and found they hit around 27 Celsius, but with a minimum of 22.5 Celsius and a high of 31.5 Celsius.

Honestly, they may be cheap, but pop the extra £20 and get a Pulse Proportional or Dimming stat, something just a bit more reliable. Having recently installed a pulse proportional stat and ceramic bulb in the same vivarium as above it stays at 28 Celsius on the probe, rock solid. It's a world of difference.

So, TL;DR: Normal behaviour, my opinion? Don't use cheap on/off stats, you get what you pay for, and sometimes it can lead to horrible results.


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## Matchoo93 (Aug 16, 2014)

Sorry for the late reply, but yeah, I got a refund on that thermostat, after emailing the chap that makes them. He insisted that there was only a temp drop of 2degrees C on his products... funnily enough he stopped replying after I showed him proof haha.

I ended up getting a Habistat Pulse one, which has kept the temps very even. A little fluctuation but only by a degree throughout the day, keeping it between 30-32 C.

Thank you!


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