This is why heaters fail.

[daninthesand]

Hi Gang.

I was really bored today. So I took apart a couple heaters. It happened to be a newer EBO and an older green ebo. I wanted to compare them.

But I was interested in more than that. I wanted to get a close look at the contacts. These little guys open and close every time your heater goes on or off. And they wear out. They can wear out in two ways.

First, they can start wearing away, in which case the distance between them is increased causing the set temperature to wander from the actual temperature reached. Because they are farther apart, it takes more pressure on the adjusting screw to bring them together. Thats why using the blue button (on the newer style) to re-calibrate them works. (I've detailed that procedure on another post)

Then there is the second, and more catastrophic way. They can get stuck together in which case the heater does not shut off. (cooked fish) These contacts open and close an electrical circuit so there is current passing between them. It is this current which causes them to "weld" together.

Below you will see two sets of contacts. Set A-B are from a newer (and still functioning) heater. The 1-2 set is from an old green ebo that had stuck on. (I caught it before any fish frying took place)

[daninthesand]

Here we see a detail of the still working set. These contact points have been in use less than 3 months and they already show some wear.

[daninthesand]

This next photo is of the old set that had welded together. They are clearly well worn and have become useless. I will try and repair them. I used to repair the ignition points on my old camaro with a soldering iron when I had less than two pennies to rub together. I'll use silver solder and see how it goes.

This is not meant to bash the EBO name. I just bought 4 more ebo's the other day. I have no complaints since you get what you pay for and the price on mail-order EBO's is great! I think ANY heater with this design (mechanical contact points) will be just as prone to failure. These points are not a whole lot different that the ones I've seen on older vehicles. And you can't get a camaro for 14.99 from an online fish store! Probably explains why all cars have electronic points these dyas. I have tronics (electronic points) which have never failed in the year or so I've had them.

Just though some of you might find this interesting.

Daniel

btw, I have more than two pennies to rub together now, but I have a lot of time on my hands.

[darcy]

LOL Dan you must have time on your hands!! Great post keep em comin!!!!
As for the Tronics I bought some once and they would not heat past 82??? I tried 4 or 5 from different LFS and all the same. Bad batch maybe, I dunno. All I have are Ebo's and have only 2 fail on me both would not heat!! For me EBO works fine.
Darcy

[daninthesand]

I have to admit I am using my tronics in tanks in which I keep adult discus or angels. I keep the temp 82 or less. I keep buying ebos because i like the price. ;D

[daninthesand]

I repaired the points and reassembled the Ebo. I can shut it on and off with the dial. It is in a bucket and so far the temp is 84. I have the temp set at "8.5" (that's how the old green ebo's were calibrated.)
I'll let you know.... ???

[daninthesand]

the temp was 88 when the heater shut off. so far so good!

[acorn54]

i don't trust any heater regardless of reputation
one fail safe way to prevent your discus from getting cooked from a faulty heater is everytime you feed your discus put your hand in the tank water to check temperature

[daninthesand]

Thats a good tip. I do it too, except I just check the thermometers.

Yes I don't trust any heater unconditionally either. But a heater can raise the temp to lethal levels in a matter of hours. If you are always home then you don't need to trust any heater. I have no choice but to trust my heaters when I'm not around.

[Mrgij01]

Just to add to the great information on this post:
Another failure point I have seen on heaters is the seals.
If you have had a heater in a tank for a long period of time and then you take it out and let it dry completely, the seals that keep the water out can crack and allow small amounts of water to get into the heater body.
I have not seen this happen every time, just something to keep in mind.

[daninthesand]

Yes, the "seals" are a bit of a pain with heaters for sure. I wonder if keeping them upside down (Ie with the dial down and the glass upright) would keep the water out?

just a thought...

[Mr. Limpet]

daninthesand,
Very nice pictures!
The automotive industry has moved away from point contacts for over 25 years. I don't quite know why no-one has gone to a solid state controller that uses a FET switch. ( A FET switch acts as the point contacts, but does not have to deal with the arcing of the current when it turns on and off). The arcing as it switches on and off is what causes the damage. These parts are dirt cheap now, but I guess the industry is just lagging behind. Maybe there is just not enough profit to be made on a new design. JMO, Paul.

[Ardan]

Nice post Dan. I've taken them apart many times and found either the contacts bad or a broken wire.

You have to have some skill to fix any of them properly.

Good Job. 8)

[barron]

Hi Dan

Good Job how did you attach the points? Mig

Also would a gold plated contacts last longer?

Barron 8)

[daninthesand]

Well, this morning the heater appears to be working. The temperature in the 5 gallon pail is 88-89. I have placed the heater into a 29 gallon tank and will see that it works (no fish, 250 watts). I was able to observe from time to time the pilot light go on and off last night. I assume things are good.

I filed the old points down to new metal (looked like copper) and then used a soldering gun and silver solder to build up the old points. I filed and buffed the new surface to look roughly the same as new ones. I was contemplating using gold but my wife caught me trying to remove the wedding ring from her finger as she slept....JK ;D

Barron, yes, gold points would likely last longer but I don't know how to obtain them or add gold to the existing ones.

It took me about an hour to disassemble the heater, solder and file the new points, reassemble and test the heater. (not including the longer submerged test) I'm sure I could do it in less than 15 minutes with the experience of this first attempt. Was it worth it? Probably not, but it was the challenge that I enjoyed.

I can get ebo's for around 15-18 bucks (US) plus shipping so my time is not really worth the effort to repair the heaters. However, if this heater proves to last longer (because of the silver points ???) then maybe eventually I'll need to buy fewer of them over the long run if i repair them as they break down. Maybe I'll take apart the heater again and check on the points' condition in a few months.

Paul, the Tronic heaters by Hagen do not use points. I understand they have the electronic thermostats. I did take one apart a while back. (I droped it and it broke actually) and I did not see any points inside. And the pictures....its kinda neat what you can do with a flatbed scanner. Can get real cool close ups of stuff. Just to make it clear....I place the item itself on the scanner. No camera involved and you get instant pix. I don't have a digicam. This is my temporary solution for small items that fit on the scanner. Try it sometime. Works great!
Daniel