Heater Settings?

[jimmyringo]

I recently thought i had problems with my heater overheating.Temperature kept going up.Eventually i bought a new heater,Hydor Theo.
Put it in ,set it to 25C and turned it on,temp gradually rose to 25....then 26....then 27.Messed about with the settings a bit and finally got the temperature to a constant 25/26C by setting the heater to 18C !!!The heater still comes on intermittently,and the temperature in my room is usually around 21C so its not rising with room temperature.My last heater did the same.Anybody got any ideas why this happens.

 

[saz326]

The markings on my heater - the one that lines up with the required temperature - is quite a fat white line. I have found that the bottom edge of the white line is the bit that I need to line up with. If I line up with the top edge of the line, then it gets far too hot.

I wonder if your markings are the same.

Otherwise, is the water circulating in your tank fully? The lights of a tank can raise the surface temperature very quickly, so if your thermometer is in the top inch or so of water it is likely to tell a different temperature to that in the rest of the water. ...Black thermo-sensors on electronic thermometers can also heat up from the lights and give a duff reading.


If you have an external filter - dont forget that heat will be lost while the water is being filtered.

 

[jimmyringo]

Otherwise, is the water circulating in your tank fully? The lights of a tank can raise the surface temperature very quickly, so if your thermometer is in the top inch or so of water it is likely to tell a different temperature to that in the rest of the water.

I actually thought of that last night.So i put one thermometer in the top right hand corner of my tank,and i sank another in the bottom left hand corner.Checked them a while later and both read 26C,and the heater still came on for a few minutes(while set at 18C).

 

[Syphoniera]

I do have an endless stream of silly suggestions...
Could it possibly be connected to some electrical problem in the house which shows in this case only because the heaters are somehow more sensitive to fluctuations in current?
I very vaguely recall once (some time ago) hearing about someone who had a radio or TV repeatedly but randomly switching on, or perhaps it was simply a volume increase - the problem turned out to be electrical in nature...???
Just at the one outlet, too, I believe - have you tried any others?
Or if using an extension cord, perhaps trying a different one?
Probably no help, but you never know.

 

[Miss Wiggle]

it's pretty simple tbh, the temp settings on heaters (all heaters) are dodgy as hell! Just use the thermometer as your guide, that's what the actual temp is and fiddle with the heater settings until it holds constant where you want it by the measurements of the thermometer.

never trust the settings on heaters

 

[tyyrlym]

The numbers on top of a heater are bald faced lies, simple as that. Run off your thermometer and don't worry about it.