Heating with Temperature Controller

[Dom]

I currently have a 300 watt heater that I use in conjunction with a temperature controller.

On one side, I have the heater and on the other, a 20 inch fan for cooling.

Here's the thing...

I leave the heater on max and rely on the controller to turn it on and off. But for some reason, the heater doesn't come on when the controller falls below the minimum temperature range.

We're only talking about 40-45 gallons of total water volume.

It almost seems like the minimum temp on the controller is higher than the max temp of the heater... but it isn't.

The heater is set to 88 and the controller is set to 78.

What am I missing?

 

[theMeat]

What’s the on off parameters. Most controllers have s setting where you can set it to go on when it falls a certain range below, and goes off within a certain range above. Meaning if you have it set to 78 deg, with .5 a degree wiggle room, it won’t come on until it gets to 77.5, and then go off at 78.5. Maybe your wiggle room is set too wide
What controller?

 

[Daniel Waters]

Unrelated, but you should set your heater to a lower temperature (but still above your controller temperature) . If your controller failed in the on position, would you really want your heater staying on till 88 degrees? You could set it to 82 for instance and still be comfortably above your controller tolerance levels. This way gives you a bit of an extra backup.

 

[Dom]

What’s the on off parameters. Most controllers have s setting where you can set it to go on when it falls a certain range below, and goes off within a certain range above. Meaning if you have it set to 78 deg, with .5 a degree wiggle room, it won’t come on until it gets to 77.5, and then go off at 78.5. Maybe your wiggle room is set too wide
What controller?

It's a generic controller module I purchased off of eBay. I put it in a project box along with an outlet; one side head and the other cool (I think I have a build thread on here about it).

I think I may get another, commercial controller. The one I have now only works in celsius, which while I have become used to, really is inconvenient.

I have it set to 26 celsius which converts to 78.8 degrees with a .5 degree wiggle room in both directions.

 

[Dom]

Unrelated, but you should set your heater to a lower temperature (but still above your controller temperature) . If your controller failed in the on position, would you really want your heater staying on till 88 degrees? You could set it to 82 for instance and still be comfortably above your controller tolerance levels. This way gives you a bit of an extra backup.

I completely agree with you. I only jacked it up because I couldn't get it to come on.

 

[theMeat]

Get yourself a digital aquatics or an apex. You don’t have to go big and fancy. Their basic agates will give you temp control plus so much more.
The best money you can put into a tank imo

 

[Daniel Waters]

I completely agree with you. I only jacked it up because I couldn't get it to come on.

That's a sign the switch is faulty. Or it may have a delay. For instance, I've removed heaters from the water or unplugged them or whatever and adjusted the temp gauge up and it wouldn't kick on until a minute or so later (I assume some type of delay built into the circuitry?).

Sometimes just moving the heater a little bit would get them to kick on, but stuff like that gives me no confidence to trust it alone. Just another good reason to use two smaller sized heaters with a master controller on both!