# sealing/resealing a heater?



## ripit (Aug 8, 2012)

So I tried my hand with purchasing a used heater (twice on ebay, one was for 2 heaters) and they all leaked. So after reading as much as I could find on it, I keep seeing people say none of them last very long, even the good/expensive ones. They all leak after a couple of years or less. It seems quite stupid to keep replacing a heater that is capable of working much longer. It also seems a waste of time to warranty them again and again over time (if it has such a warranty). 

So what about resealing one that has leaked a little, or just sealing a new one? Maybe I could just forget about using them submerged? The quick and crude solution would be to encase the top and a bit of the glass in silicone. I'm sure there are other things I could come up with. If I could get the top off I could encase the top portion (inside the tube) with silicone. I of course would have to be carfull not to interfere with the temp sensor. Perhaps just reseal the top with silicone?

It seems redicilious to have to spend a fortune on titanium heaters for multiple tanks (and are they eventually going to leak or go bad too)?

I do have a heater with a cracked tube to play with experimenting, getting one apart?

If a non submergable heater can work with the head above water, then wouldn't a submergable one work with the head above water weather it leeks or not (I'm assuming water will not get in with the head above water, even if the seals are bad). Perhaps I should forget about submerging them?

Does anyone have any thoughts on that?


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## Alasse (Mar 12, 2009)

Personally i would never try to modify a new one and definately would not touch one thats leaked or cracked.

My life, not to mention my fishes lives are worth too much to me. I just go buy a new one

(many submersible heaters will work with just the end out of the water)


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## jrman83 (Jul 9, 2010)

Messing with something like that leaves the potential to get electrocuted. Even an Electrician wouldn't try something like that. $20-$50, or however much the ones you need cost is not worth your life.

Stop trying to buy used ones. Get new brand name heaters and they can last for quite a few years.


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## coralbandit (Jul 29, 2012)

everyone reading this ; DO NOT ATTEMPT. if adding silicone was the cure don't you think they would .Didn't even know there was used heaters?They work or you throw them away?


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## ripit (Aug 8, 2012)

I hadn't planned on trying to repair the cracked one. It was just more to see how they are sealed at the top (I have 2 coming from warranty replacement that are the same brand). From the appearance of them, they seem to be a complete unit glued/sealed into a glass tube. As far as resealing one, I was thinking along the lines of withdrawing the unit from the tube a bit, and sealing the top when putting it back in with a little silicone (around where its own seals are) without any Assembly or modification to the working parts. As far as sealing a new one, I'm talking about encasing the head and a small portion of the glass tube with a thin layer of silicone (with no disassembly at all). 
In no manner would the working parts be altered at all. 

So for those of you that use submergable heaters, what do you do, just replace them every few years?


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## ripit (Aug 8, 2012)

Fyi I gave up on used ones pretty quick (especially after reading that they don't last more than a couple of years till they leek for many people). I'm thinking more along the lines of preventing new ones from leaking. Looking at the cracked one, the cover is just a loose fitting rubber cap (doesn't seal). The top of the heater is just a rubber plug to seal in the glass. 

" if adding silicone was the cure don't you think they would"

They basically do. It has a rubber seal and a little silicone would refresh the surface of that rubber seal.


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## ripit (Aug 8, 2012)

Here is another question. If they sometimes go a few years and leak, are you not taking a risk using them period? Are you expected to periodically replace them before they leak?


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## coralbandit (Jul 29, 2012)

Yes! possibly every 3-5 years.Not certain but think if heater is plugged into gfci(ground fault circuit interupter) then you won't find out hard way the heater isn't working.GFC I is not a "power strip" .But can be purchased as extension outlet .


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## ripit (Aug 8, 2012)

coralbandit said:


> Yes! possibly every 3-5 years.


And can this be avoided by just keeping the head above water for the entire life of the heater (in particular because I have read plenty enough stories searching for information on it of them leaking within a year or two in some cases).


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## coralbandit (Jul 29, 2012)

there is a line on all submersible heaters showing how much HAS to be in water.None of them have to be completely submerged to operate properly.Usually due to water conditions(TDS) most non submersible heaters still crack.


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## Alasse (Mar 12, 2009)

Some of my submersible heaters are still going after 8-9 yrs. Some dont even last one.

When i do tank maintenance, they are turned off and checked for moisture, if i see condensation, they are binned and new ones bought


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## ripit (Aug 8, 2012)

Looking at how the cracked one is built, its no wonder they leak. The entire heater is a single assembly that can be withdrawn from the glass tube as a unit. There is just a rubber plug with no sealant to seal it off. the rubber was still soft and pliable. I don't think that they leaked around the main seal though but who knows. 4 different ones had just a bit of water around the temperature scale. I think they leaked through the adjusting knob? Regardless, with no sealant to bond the plug it could have very tiny leaks. Ever time the heater gets hot and then cold, the pressure inside the tube is going to climb and then fall. It kind of makes me wonder if they slowly suck very tiny amounts of water in on the cooling cycle, and eventually they suck in enough you start to see condensation. It certainly would make for good planned obsolescence?

These are visi-therm heaters by the way.


On a side note, the one that cracked was not from a leek, it was from stupidity. I did a water change without unplugging the heater. It also had just a little bit of water but that has nothing to do with it cracking.


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## navigator black (Jan 3, 2012)

I try my best not to use heaters, as they are expensive and short lived. I know I can't help but sound like a grumpy old man, but when you bought good heaters like ebo-jaegers 25 years ago, they were dead reliable for 10 years, and I had some make it closer to 20. I have one with a tiny touch of condensation in it that I bought in 1992 and that is still exact and reliable.
That is pretty remarakble, since the batch I bought after (10 of the same brand) lasted 3-5 years maximum. My Hagen manufactured heaters seem to go for a couple of years and then shut off, and I have done no better than that with other brands.
They are built to fail, like $40 light bulbs. Based on the old models, it is easy to make good ones. It just isn't profitable.
I have multiple tanks, and try to avoid species that need heaters. The room I keep the fish in is the warmest in the house, since it contains the water heater and furnace. It sits at 22-23c in winter, while the rest of the house is kept at 19-20c. That is sufficient for most livebearers, killifish, West African cichlids, Cordoras and a lot of barbs and tetras.

I have once put my hand into a tank where the heater had cracked. Don't do it. Don't risk it, and don't modify the poor designs with really knowing what you are doing. I have also had their thermostats fail and found my tank at 35c (fish soup). I would be afraid the modification would affect their low-grade thermostats.


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## ripit (Aug 8, 2012)

The design of these is so simple I could probably rebuild or repair one but I don't think it is worth the trouble if it has functional issues. Resealing it or improving the seal seems a simple task to me but that is with the knowledge I have about such items. The only difficulty I see is getting it apart without breaking anything (imagine trying to remove a wine cork without a cork screw and imagine the bottle neck is paper thin). It probably varies depending on the design how easily or successfully they could be resealed or have the seal improved. As others have said, it can be quite dangerous so I wouldn't mess with one unless you know what you are doing (and I do). 

As far as them being built to fail, I think its a combination of making them as cheap as possible to maximize profit, and making them to fail, to obtain more profit when you have to keep replacing them. They do not seem to be built to last. If anyone is familiar with points in a car, these use basically the same thing. Points in a car were considered a maintenance item like spark plugs on cars because they are designed to fail. Under normal use, they slowly destroy themselves. There is a reason they quit using points in cars when electronic ignitions became possible to mass produce. Of course like a spark plug, some last longer than others and we have the technology now to make them last very long (like iridium spark plugs in a car that can last 100,000 miles). They don't seem to use that technology in these though. Likewise the seals do not seem to be designed to last (and it would be very easy to design one that would). It looks like it probably leaked from the day it was made (very, very tiny leaks). With it getting hot and cold its only a matter of time before it sucks in enough water to show condensation. There is a reason you use gasket sealer when installing a water pump in a car. There is a reason you use teflon tape when screwing water or air lines together. Its not new technology but seems to be skipped on this heater (to make you have to buy a new one in a few years or just to make it cheaper to make?).


As far as putting my hand in a tank with a cracked heater, I'm kind of new to fish right now, buy years ago when I was very young I kept fish for a while and even did a little breeding and selling (its coming back to me but that was a long time ago). I once knocked the light in a tank and reached in an pulled it out (got a nice little shock, not too fun).


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## majerah1 (Oct 29, 2010)

I myself have three visitherms, and have had no issues thus far. I have two hydors, had three but I found one with the bottom broken off in the bottom of the tank. It is common for many fish keepers to replace theirs yearly. Some wait three years but tbh every glass heater submersible or no, has the potential to malfunction, as does any tank seal or any filter. There is always some risk somewhere with equipment.


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## gar1948 (Jan 25, 2012)

I would never buy a used heater and never modify one for any reason. If you purchase a good quality heater they should last many years. I have only had one fail in many years and always keep a backup heater for each tank just in case.


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