# Oase Filtosmart Thermo 100 Not Heating Water



## Franklin2018 (27 Jan 2020)

Hi
I'm in the process of setting up a new 35l tank and bought an Oase Filtosmart Thermo 100 as I liked the idea of not having the heater in the tank.
After I set it up though I noticed that the water temperature in the tank was dropping, and over the course of a day dropped from 23° to 11.5°.  I contacted the company I bought it from and told them it looks like the heater is broken, so they sent a new one out which arrived the following day.  
I installed the second heater, but this one is failing to heat the water too.  By this time, the water was pretty cold, so I wondered if maybe the heater wasn't in contact with the water long enough to actually heat it up, so I added warm water to bring it up to temp.  
I also tried removing the ceramic media thinking that maybe it was blocking the flow around the heater, but that had no effect either.  Yesterday I tried the heater inside the cannister as well as the first heater directly in the tank and switched both on to max (32°).  The water then started rising, albeit very slowly, and by night it had reached around 21°.  At this point I reduced the heater temp to 25° on both heaters and went to bed.
This morning, the tank temp is 11.5°!
Has anybody else come across this, or does anyone have any ideas on how to remedy it?  I've sent a message over to Oase, as well as the company I bought it from also, but thought I'd see if there's anyone who has experience it themselves.
Thanks in advance


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## Fisher2007 (27 Jan 2020)

I can only presume you've been unlucky and got two dodgy heaters.  Unlikely but with both removed from the filter and in the tank they should have heater the tank up.  Just to check though, when in the tank was there any flow in there?  Heaters need water movement around them to function properly.  Clutching at straws a little


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## Tim Harrison (27 Jan 2020)

Welcome to UKAPS 
Maybe @Siege will be able to offer some advice too.


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## Siege (27 Jan 2020)

Sounds like your 1st thought was correct, flow is not getting around the heater. 
Have you purged all the air out of the filter, if you tilt it do you hear a gushing sound and bubbles coming out of the filter?

is it primed properly, you may have a slight trickle going down the inlet tube and it will still flow but not at full power. If you have a small piece of 12mm tubing put that in the outlet lily pipe and suck to assist with priming. Alternatively empty the filter, take the outlet over a bucket and suck to prime fully. When at full flow, close the outlet and reattach.

hope that helps.

S.

ps. Where did you buy it?


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## Franklin2018 (27 Jan 2020)

Problem solved, it wasn’t an issue with the heater at all, it was actually the digital thermometer I was using which was completely wrong.  I thought I’d try a regular glass thermometer as I’d tried everything else, and I was a bit confused how the water could drop to 11 degrees when the ambient room temp is 18-20, lo and behold the tank is actually sitting at 21.  Feeling a tad foolish, but at least I don’t have a dodgy filter and heater!


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