Aquarium Heater

[Raymond Sands]

I have just started my first aquarium. The tank contains a heater and a filter. There are no fish at the moment. The heater has been on for more than 24 hours (on two occasions) and the light has never come on. It is a resun. The temperature was set at 24 degrees celcius. Please help.
Thank you,
Raymond.

 

[Madisonkeug]

I have just started my first aquarium. The tank contains a heater and a filter. There are no fish at the moment. The heater has been on for more than 24 hours (on two occasions) and the light has never come on. It is a resun. The temperature was set at 24 degrees celcius. Please help.
Thank you,
Raymond.

What is the temp of the water currently? If it’s already at 24° or higher it shouldn’t turn on

 

[Essjay]

I've not heard of a heater which doesn't have a light but to make sure - this heater does have a light?

You could try unplugging it, turning the setting up to max, then plugging it back into see if the light comes on then. If it does you know it's working. Then unplug it and turn it back down again.

The thermostats on heaters are notoriously badly calibrated. The majority do not heat the water to the number on the dial. Just because it's set to 24 doesn't mean it will get the water to 24 - it could be as low as 20, for example.
The way to set most heaters is by adjusting the dial to get the water temperature as measured by a thermometer in the water to the temp you want.

 

[Stanster59]

the same could be said for most thermometers ?