I’m a big proponent of controllers for all heaters. At the very least they are a second line of defense should the heater get stuck in the on position. I noticed something unusual in my tank today…my heater has decided to follow a lower temperature.
You can see in this image that the temperature starts to drop and then oscillates there and then again at a couple of other temperatures. Looking at the relay activity, the heater has been left “On” 24/7 for the entire period shown here. So the heater thermometer is bouncing all over the place. For whatever reason, I’ve thought heaters would over-heat, but hadn’t considered under-heating.
I’ve heard good things about them. The heater itself seems to be the issue here rather than the controller. It’s strange that the temp the heater is trying to keep to is bouncing around so much.
I dot use the tstat on the heater, i turn it all the was up and the controller cycles power as water temp changes. I however dont have any cool graphs like you. I just have jumped off my roof yet to buy the apex that i need. Im gonna need moe then what comes in the box and thats not gonna be cheap. So im still using timers and seperate monitors.
I like using the internal thermostat bc it’s another layer of protection should your controller fail.
I would turn it up a little high though and see what happens. It looks like your heater is shutting itself off when your controller is telling it to turn on.
[quote=“beadlocked450r, post:4, topic:8358”]
I dot use the tstat on the heater, i turn it all the was up and the controller cycles power as water temp changes. I however dont have any cool graphs like you. I just have jumped off my roof yet to buy the apex that i need. Im gonna need moe then what comes in the box and thats not gonna be cheap. So im still using timers and seperate monitors.[/quote]
I’m using a Reef Angel. I’ve had it for years and it works quite well. You can do just about everything with the base unit plus a wifi module ($350 total, if memory serves).
[quote=“bnelson, post:5, topic:8358”]
I like using the internal thermostat bc it’s another layer of protection should your controller fail.
I would turn it up a little high though and see what happens. It looks like your heater is shutting itself off when your controller is telling it to turn on.[/quote]
Exactly.
I see it as a possible heating/temp sensing lag. depending on where the temp probe is. and the watts of the heater. You have large heaters, 1800 watts. if your controller sensor is downstream of flow in the sump from the heaters, they may warm the sump water, smaller volume, which would shut down the controller. meanwhile the tank water is cooler coming down to the sump. it’s fall, the house is cooler and nights too. so at lights, the tank cools , while the smaller sump is cycled up and down with the heater. perhaps relocate your controller temp probe. to the tank near the overflow. halfway deep. 1800 watts can warm the sump volume real fast then shut down. meanwhile the larger tank volume gets a small shot of warmer water from the sump, then cools some more. Just some flow thoughts. and temp probe location to experiment with.
The sensor location could have something to do with it too. I turned the temp on the heater up and it is behaving better. However, the heater is still clearly turning itself off. There are a few examples in this graph, I just highlighted one. I overlayed the relay activity for the heater (purple) on the temperature plot (red). You can see at 11PM, the relay is on, but the temp in the tank drops.
I’ll try moving the temperature probe up to my overflow, that’s as far away as I can get from the heater. It is also worth noting that the updates are only once every 5 minutes on this chart.
I like to zip tie the temperature probe to the overflow inlets in my sump. That way it’s measuring the water coming from the tank and not the sump temperature.
yes Bryant, thats what i was thinking about. the main tank is more stable and slower changing in temp than a smaller sump with a really big heater in it. and its the tank temp that is important.
Oh sorry, that was Jason with the 1800 watt heater. He has a really big system. I just use 100w and 150w e s myself with built in temp controller. keep it in the sump. the trick is to set them in a bucket of water first with a thermometer and small power head to circ the water. then just dial it in to your desired setting. much easier than trying to adjust it in the tank.
