David Nebenzahl wrote:

First of all, it is an approved, UL/CSA tested, and, most importantly,
code-approved (US building code) wiring method. If it was as all-fired
bad as folks here claim, why would it still be allowed? After all, the
building codes tend to err on the side of caution.

They are allowed by the NEC because they are listed by UL.

UL used allow #12 wire in backstabs. Not anymore. Apparently their
original standard was flawed. (How about the #12 backstabs in use?)

Seems like several failures come up here in this rather limited forum
each year. IMHO they have minimal contact area, minimal clamping
pressure, and in slightly adverse environments are subject to chemical
deterioration. You will probably have no problem with backstabs. You
also probably won't need the pressure relief valve on your water heater.
I don't see any reason to take the chance.

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bud--