Heater failure due to chemistry?

[plannersteve]

I have just had a heater failure.  It trips the GFI and when disconnected the tub pump runs.  There is a build up of which crystalline material around one of the electrical connections and a support bolt.  See picture.  This white build up is new since I last changed water about a month ago, or at least there was none on floor below heater.  While it appears that there was some leakage that formed this deposit under the heater as well, it was not leaking when I opened it.  The brown material around the electrical connection has been there for at least a year.

I'm using the Dichlor/Bleach method to sanitize my water and have been extremely happy with the results.  I've got a Taylor test kit and routinely check pH and free chlorine.  pH is almost always around 7.4 to 7.6, although I've had occasional episodes where pH might have gone high or low for a day or two.  I usually test pH about 3 or 4 times per week.  I maintain free chlorine around 2 ppm, maybe a bit lower.  I add calcium increaser to get my CH up to 150-160 at start.  I adjust to get TA to 80-90.  Usually I don't have to add anything, that is where it falls out after increasing CH.

My hot tub supplier told me that my warranty claim will likely be denied because this appears to be a chemistry problem.  Whatever, I just want to get to the bottom of what happened so I'm not facing this again in a year.

Any thoughts as to what causes this kind of failure appreciated.  Also, what should I be looking for when I take this heater out?  Should I be concerned that my pump is also at risk?

Thanks.

[plannersteve]

OK, did I break some unspoken rule with this post?  Certainly some of you have seen a heater failure before?  I'm looking for help so I don't repeat this if it is something I am doing wrong.  I promise I won't call you as a witness in my dispute with my hot tub manufacturer.😁

Thank you!

[castletonia]

How old was the heater element?  It looks like it did leak which is why all the white residue.  The leak was likely small, more like it was seeping and then calcium in the water is what sealed it.  That picture alone wouldn't determine warranty worthiness.  The inside of the heater canister and what the actual element looks like would.  If there is evidence of corrosion, scale build up, etc, then yes the warranty claim would likely be denied.  The numbers you listed all seem to be good.  A few random days here and there would not result in a heater failure or physical evidence.  

[plannersteve]

Thanks for the response.  The heater was two years old.  The interior had no scale and the element looked like new (compared to the one I replaced it with).  I would say that it did look discolored on the interior at the point where the grounding bolt is attached.

[castletonia]

In my experience, if a manufacturer is going to state that water chemistry caused the failure I would expect the element to either have corrosion or be coated in scale or the inside of the heater canister to have scale.