Uv Steriliser Heating Up Water?

[kad191]

Had an eventful couple of days so please bare with me.

When I got my 240ltr tank I was going to keep discus so I bought an 8w vectron steriliser. I changed my mind on discus so haven't fitted it until now for water clarity purposes.

Friday night I was woken by the house phone beeping as the power had gone off, the RCD had tripped on the consumer unit and after a long search by phone light I found it to be the tank that was tripping it. I inspected everything electrical on the tank and my heater had cracked and was full of water, all fish ok thank god. It was still under warranty so my lfs replaced it this morning. Whilst I was at it I plumed in my uv filter run off the output from my fluval 306. I set the heater to the correct temp and ever since I have noticed my tank temp steadily rise from 25.5 oC to 27.3oC.

As far as I can see the heater pilot light hasn't been on and I've even unplugged the heater to see if it still rises. The only other thing different is the UV. Could an 8w bulb really heat up 240ltrs like that?

The ambient air temp has been around 18oC all day and is currently 21oC now the heating is on.

Anyone any ideas??

 

[KirkyArcher]

It sounds to me like it's the heater is just not calibrated correctly and you should really only take note of what your thermometer is reading, Just had a touch of all the exposed surfaces of my 16w V2 300 steriliser on my 125ltr tank and all is pretty cool to me, My Fluval "E" heater is set at 24.5°C and the tank thermometer reads 24°C. Also for a 240ltr tank you should really have at least a V2 300 or even the 400 steriliser unless you have turned the flow rate of your 306 filter and its 780litres/hr flow rate down very low you will see limited benefit from it as the 8w 200 unit is only effective on filter rates up to 680 litres/Hour  

 

[kad191]

The temp did drop when I unplugged the heater so it is that. I've got a spray bar on the filter which slows the rate plus I turn it down anyway, seems to cause a lot of turbulence in the tank when flat out.