# CHE and On/Off Thermostat



## ColleenHorwood (Mar 22, 2021)

Hi, so, where I live, I have not been able to find a pulse proportional thermostat. Not even online. So I'm using on/ off. I know it shortens the lifespan of the ceramic heat emitter. Other than that, is it dangerous? Just wondering. Thanks.


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## Malc (Oct 27, 2009)

ColleenHorwood said:


> Hi, so, where I live, I have not been able to find a pulse proportional thermostat. Not even online. So I'm using on/ off. I know it shortens the lifespan of the ceramic heat emitter. Other than that, is it dangerous? Just wondering. Thanks.


Personally I wouldn't use an ON/OF stat with a ceramic - the resulting temperature swing will be considerable. Years ago I was doing some testing to develop my own thermostat and this was the result of the data log overnight using an on/off sat with a 150w ceramic heater. The set point was 32c










The swing was from 27c to over 40c.

If you can get a dimming thermostat that would still work with a ceramic and it will still give you a steady temperature.


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## LiasisUK (Sep 30, 2019)

Dimming would work fine with a ceramic


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## ColleenHorwood (Mar 22, 2021)

Malc said:


> Personally I wouldn't use an ON/OF stat with a ceramic - the resulting temperature swing will be considerable. Years ago I was doing some testing to develop my own thermostat and this was the result of the data log overnight using an on/off sat with a 150w ceramic heater. The set point was 32c
> 
> 
> 
> ...


Great. Just two days ago I was at the pet store and they had the exo Terra 600w dimming/pulse proportional thermostat so I bought it. I just hooked it up today. Also I'm waiting on the order of a 6x2x3 foot PVC enclosure for my common boa and I'm wondering if a 150 watt ceramic heat emitter will be strong enough for that size or if you recommend something higher? Thanks


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## Malc (Oct 27, 2009)

PVC is a good insulator so it will retain heat well. It's hard to say if a 150w will be sufficient or a higher wattage is better. Personally its easier if a 250w heater is used as a 150w will work harder to maintain temperature than the 250w. A poor analogy is two cars, one with a 1lrt engine the other a 3.5ltr. Both are capable of doing 70mph on a motor/ free way, but the 1ltr will be working harder to get to 70mph and maintain it when it comes to a hill, where as the 3.5 litre powered car will get there faster, and maintain 70mph regardless of the terrain 

In the UK we have distant selling laws, so if you buy on line you have 7 days in which to return an item for any reason. So you could try a 150w for a day or so, and if it works OK then keep it, or if you feel its struggling, then return it in the original packaging for refund and purchase the next one up. Maybe Canada has similar laws. Alternatively see what the shop owner has to say, and ask if you could return a 150w if you find it struggles ?


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## ColleenHorwood (Mar 22, 2021)

I currently have a surplus of 150w so enough to start off with and see. I prefer not to shop online but where I live does not cater much to reptiles so sometimes it is hard and I am forced to. Also it is much cheaper!


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