How They Work:
Heaters basically resist current flow and
doing so heat. Most common rating of heaters is
5.5k although some models have 4.0kw. A 5.5kw
heater operating at 230vac you should see a 5-6
degree per hour water temperature increase.
How do they Fail?
The "official" statement from those who make
heaters is that if it doesn't fail instantly,
the only reason afterward is enduser water
quality. We did service on one brand that only
warrantee their heaters up to the first use.
After that, nothing. Again, the belief is that
enduser water quality or lack thereof causes
heaters to fail. We no longer service those
But in the field,
its hard to determine. Yes, likely the most
common reason the heater fails is water quality
but there is only so much an enduser can do.
Some ask why don't they make elements that last
but my answer has always been the same; would
you pay 3x what you pay now for a "better
quality" heater? In reality, most of us would
not. So we try to maintain heaters and see what
happens. I have seen the same style heater last
less than a year and more then 10. So maybe
there is something to the industry's blame.
We now offer
"treated" heater elements. They have a coating
to extend their life.
In most cases,
you can see corrosion on the element and that
explains the failure. BUT.. elements can have pinholes and
that pinhole will leak current and the gfci
senses and POP. So I have seen heaters over the
years that looked fine yet the element somewhere
is shorting out and the GFCI pops. Solution is