How to control oil filled heater when it keeps on heating while it's off?

Wolfen

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I have a radiant oil heater hook up to a heater controller. It's set up to 80° in my leopard tortoise's night box.

Controller cuts off the power to the heater when the temperature reaches 80° but they made the heater to keep on heating for a while even when it's off. So the temperature of the night box goes up to like 95° before it comes down again to 79° and the controller turns it back on and it heats up to 90s again.

How do you control this?
 

Wolfen

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Get an external thermostat.
It IS hooked up to an external thermostat.
Thermostat controls the heater but the heater keeps putting out heat for few minutes even it got turned off (it's supposed to do this) making the enclosure 15 degrees hotter

I wouldn't even know this if I didn't have the option to review the historical temperature graphs in the enclosure

@Tom @Markw84 @Yvonne G
 
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wellington

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Not sure if you can. I would replace it with one that doesn't do that. If you can't return it then keep it on hand for a back up
 

Tom

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It IS hooked up to an external thermostat.
Thermostat controls the heater but the heater keeps putting out heat for few minutes even it got turned off (it's supposed to do this) making the enclosure 15 degrees hotter.
What type of thermostat are you using?

What size box is it in?

What size and type oil heater? What setting is it on? High, med, or low?

I runs a dozen of those daily, and none of mine do this. Let's see if we can figure out what is different in your set up.
 

Wolfen

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What type of thermostat are you using?

What size box is it in?

What size and type oil heater? What setting is it on? High, med, or low?

I runs a dozen of those daily, and none of mine do this. Let's see if we can figure out what is different in your set up.

It's an inkbird thermostat rated for more than 1000w.
Box is 2x4 wooden and insulated with 1.5" rigid foam on top, bottom and all 4 sides. Except the door. The door got plastic flaps.

Heater is 700w and running between medium and high.
 

turtlesteve

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This sounds like a “tuning” problem. This is a well known issue with temperature and process controllers (used for industrial or lab equipment). Most will have tuning features designed to suppress the problem.

Fundamentally this happens because there is a time lag between the heater switching state (off to on or vice versa) and the resulting heat being detected by the thermostat. So, the system overshoots and oscillates in temperature.

There are a few ways you could fix this:
- put the thermostat closer to the heater
- turn the heater power down
- buy an industrial controller to replace the on-off thermostat
 

Maro2Bear

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You could also just try setting your thermostat to 75, knowing full well that the radiator will continue to heat up another 10 degrees or so. Just tweak it over time.
 

Yvonne G

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I have a radiant oil heater hook up to a heater controller. It's set up to 80° in my leopard tortoise's night box.

Controller cuts off the power to the heater when the temperature reaches 80° but they made the heater to keep on heating for a while even when it's off. So the temperature of the night box goes up to like 95° before it comes down again to 79° and the controller turns it back on and it heats up to 90s again.

How do you control this?
The oil inside the heater is still hot, so even though the electricity has shut off the hot oil still radiates heat. It takes a while to cool down.
 

Markw84

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Place the sensor for the thermostat near the heater. You should run a muffin fan when the heater's on (small computer fan). The fan should be blowing from the heater towards the middle of the night box. Put the sensor a foot or so from the heater but in the direction the fan is blowing. that will solve your problem.
 

Wolfen

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Place the sensor for the thermostat near the heater. You should run a muffin fan when the heater's on (small computer fan). The fan should be blowing from the heater towards the middle of the night box. Put the sensor a foot or so from the heater but in the direction the fan is blowing. that will solve your problem.
Will try
 

Tom

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It's an inkbird thermostat rated for more than 1000w.
Box is 2x4 wooden and insulated with 1.5" rigid foam on top, bottom and all 4 sides. Except the door. The door got plastic flaps.

Heater is 700w and running between medium and high.
I see the problem. The box is too small for this type of heater. I have a 4x4 box with a 400 watt oil heater set low for a temperate species and I don't have this problem. I only use the 700 watt ones on low and in a 4x8' box. For a 2x4' box, I think you'd be better served with a Kane mat and RHP overhead.

You might try a digital proportional thermostat, but I'm not sure how well that would work with an oil heater. I've never tried that combo. I use the ones from Helix. Model DBS 1000.
 

Wolfen

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Do you guys use a humidifier for outdoor night boxes?

I feel like I need one because the humidity escapes through the door flaps.
And sometimes humidity goes below 60%
 
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