Faulty Heater?

[Mola Mola]

I got a heater with my new 80L tank yesterday along with an standard glass thermometer.

The heater was originally set to 28C, but the thermometer read 31C this morning. I turned the heater down to 26C a couple of hours ago, but the water is still 31C.

I could imagine that the water takes a long time to cool down, but I am more worried by the fact that the heater light is currently on, and so seems to be actively heating. I have seen the light come on and off, so the heater definitely can switch itself on and off but, it seems, not at the right temperature.

Am I right in thinking that the heater is likely faulty? To be still heating at a 5 degree difference seems wrong to me.

I am currently doing a fish-less cycle BTW.

 

[Louiseness]

Sounds like it's broken. I had a second hand heater come with a tank and despite me setting it to 18C (the lowest it would go on) it was still heating my tank to 27C or so

 

[Tizer]

When turned out out of water they break very very quickly and easily. Any chance you did that before submerging it? It does sound broken.

 

[Mola Mola]

When turned out out of water they break very very quickly and easily. Any chance you did that before submerging it? It does sound broken.

No, I was very careful about that.

I've turned it down to 24C now and it switched off the moment I did that, so I'll keep an eye on it.

When I had the problem at 28C I called the shop and they just suggested that I turn it down. I just not sure what to expect in terms of the accuracy of these things, and so when to ask for a replacement.

 

[ZoddyZod]

Heater thermostats are notoriously innacurate. Mine is set at 28c but the water is a constant 25c.

Leave the heater as is for a few more hours. A large volume of water will take quite a while to cool down several degrees. If it still doesn't drop, then unplug the heater completely and wait some more......still no drop? Your thermometer is broken.

 

[Louiseness]

If it's set for 26C and is actively heating (light on) when your thermometer is 31C I'd say it's pretty broken!

They should only kick in when the water around them gets cooler than the temperature the heater is set to come on at, so if it's not doing that I'd be getting a different one.

 

[Aqua Tom]

Buy a new one. They are not expensive & it will save you the worry.

Tom

 

[Mola Mola]

Buy a new one. They are not expensive & it will save you the worry.

Thanks. Although I think I'll just take it back. I'd be disappointed if the fish shop disagreed about replacing it.

I have set it to 24C and it has kicked in at 29C, so I guess that it is just misreading by 5C (assuming that the thermometer is reading correctly, of course).

 

[eaglesaquarium]

What is the temp of the room? The water will "cool" faster in a cooler room. As much of the US is experiencing a heatwave, it isn't surprising that your tank temp would be a bit high.

 

[Smells a bit fishy]

Sounds to me like as you correctly said the thermostat is out, by quite a bit ( normally it's a degree or 2 out).

Yeh if you bought it recently take it back, and get a different brand

 

[andyjw1]

Use the setting on the heater as a guide only, make sure you have a separate thermostat that is accurate.
A quick test is to take your stat out of the tank for a few minutes, even run it under some cold water. It should respond quickly, then put it back and take a reading after 10 minutes.

 

[Mola Mola]

Use the setting on the heater as a guide only, make sure you have a separate thermostat that is accurate.
A quick test is to take your stat out of the tank for a few minutes, even run it under some cold water. It should respond quickly, then put it back and take a reading after 10 minutes.

Thanks. I did that on thermometer yesterday (ran it under the tap), and it went down quickly and then quickly back up in the tank. I don't know if it is accurate, but it certainly changes with temperature.

I took the heater back today and got it changed. The guy in the fish shop checked the old one and confirmed that it was still heating even when set low.

Mind you, I've just put the new one in, and it might be doing the same thing. The thermometer is reading 31C, the heater is set to 28C and is currently heating. I suppose it could be a faulty batch.

I'm going to order another thermometer (probably digital) as another check.

When I went out this morning at 11am the thermometer was reading 31C, and when I came back at 3pm, it is still reading 31C, and there was no heater in for those four hours. I'm not sure what room temperature is, but I would say it is reasonably cool.

Would you expect the 80L tank to stay at 31C for four hours without a heater? (if not, I suppose the thermometer might be bust)

 

[BigbruiserAl]

Just as a FYI, the weather plays hell with tanks. Im in the UK and the past 2 days my room temp is 25.4c (I have to monitor room temp as i keep posion dart frogs in the same room)
The heater is set to 24c but the tank is always 26c+ because the hood is a very tight fit leaving little air exchange, the room temp is high, the volume of water is large so hardly cools in 24hrs (350L) and of course the 4 T5 lights add to heat.

 

[StandbySetting]

Don't order a digital thermometer, they're no as accurate as the spirit ones unless you pay over the odds for them.