Thermostat FAQ

Proportional verses On/Off

The Vivarium Electronics Ve-200, VE-300 and VE-300X2 are what is called "proportional" thermostats. "Proportional" refers to the gradual adjustment (up and down) of power output until the set temperature is maintained. Other, non proportional thermostats use an "on/off" approach and usually have a 1 or 2 degree (or more in cheaper ones) "slop". They turn on 100% when the temperature falls a degree or two below the set point and they stay on until the temperature gets to the set point, and often have momentum and go 1 or more degrees beyond the set point. This means that if you set your thermostat at 80 degrees your actual temps can vary between as low as 76-78 degrees and as high as 82-84 degrees. A roller coaster ride for your animals. You can think of the proportional thermostat more like a light dimmer with a brain constantly adjusting itself to maintain a much more precise temperature. The "slop" in proportional thermostats is usually measured in 1/10 degrees. The Vivarium Electronics models also offer a very easy to use "Night Drop" capability. It is built in to the VE-300 and VE-300X2 and can be added later to the VE-100 and VE-200 models. This makes it super easy to cycle your animals during breeding season without controlling the temperature of the whole room or manually changing the settings twice a day.

Proportional thermostats are just about required if you are using it for an incubator. The "slop" in on/off models can be a real problem. Especially in cheaper, less accurate models and in small incubators which are more susceptible to temperature variations. We prefer them for all of our animals though the on/off models will work well if used for supplemental basking areas or in situations where economy is key. The VE-100 is an on off style thermostat that feature silent operation- no relay "click". Just remember, like with anything else, you get what you pay for. DON'T make the mistake of keeping your multi thousand dollar high end herp collection on heat controlled by a cheap thermostat. Just about any "old timer" in the reptile business can tell you a story about "cooking" some prized animals. The VE-100/200/300/300X2 all feature a safety backup relay built in that will cut all output power if the probe temperature reading rises more than 6 degrees above the set point. This can be very very critical in smaller tub rack systems with belly heat.

What is the difference between the Dwyer, Ranco, Johnson Controls, VE HobbyStat and the VE-100 other than the cost- All are on/off thermostats?

The Dwyer, Ranco, Johnson Controls and VE-100 are on/off style thermostats, so what is the difference?

First, three have a digital readout rather than a "tweak and find out" setting that some pet store models have. The HobbyStat has a large, easy to read dial. This can be helpful in getting your temps set a lot quicker and more conveniently. The Ranco, Johnson and VE-100 probes also double as a thermometer wherever you place it. The VE-100 also offers the convenience of a clock, set point and actula probe temp on the main display. The VE-100 is the only one of the three that is a table top mount so no bracket or screws are required. It is easy to view sitting on top of your racks or cages.

Another big difference is the power capacity. The Dwyer, Ranco, andJohnson are good for about 1500 watts and the VE-100 for 700 watts and the HobbyStat for 400 watts. For most users this does not make a lot of difference. The one big exception to this is if you are using a thermostat to control a room heater. Generally oil filled space heaters work well in reptile rooms but use about 1200 watts of power. For this application the Dwyer is the obvious choice. For rack or cage use the VE-100 or HobbyStat offers good looks, silent operation and more than enough power capacity to get the job done!

From a purely practical standpoint, in most cases you will have more money (animals) riding on the performance of your thermostat than you will in the thermostat itself. As the value of your collection grows we strongly urge you to invest in the best thermostat available to you.

Safety backups - When and why they are needed

No matter how much you spend or what model/brand you get your thermostat CAN FAIL! A number of things can lead to this happening: power surges, children, overloading, rat chewing on a poorly placed probe, bad luck or karma, etc. BE READY, you can use a simple, less expensive thermostat as a back up. Odds of both failing at the same time are much, much less! In many cases this may not be needed, especially with the relay safety backup in the VE thermostats. If careful consideration is given to the maximum heat possible to a given cage or tub you may find it impossible to get to fatal temps. In smaller tubs, like 5-12 quart sizes, you may find that even with low wattage heat tape that your tubs could potentially reach fatal temps easily! With the VE-100 as your backup and either the VE-200 or VE-300 as your primary the units will stack for a very neat, organized appearance.

Most failures we hear about are actually not failures of the thermostat, but failures of the probe. Often a probe can be dislodged with constant moving of tubs in racks or in cages. Some thermostats can not differentiate between normal circumstances and when your heat element is not working properly. The Vivarium Electronics VE-300 model comes with a full set of alarms to de activate the heat ouput and sound a loud buzzer when there is an issue. For example- with most thermostats if the probe is dislodged from the heater the thermostat will simply turn up (or on) the power, never realizing the heat element has surpassed the set point. With the VE-300 and VE-300X2 if the setpoint is not reached for more than 30 continuous minutes the alarm will let you know- and shut off the power output!

Got more questions?

If you have a question we didn't cover here, just send us an email, we will be glad to help!