Autocirc can be uninstalled and the pipe cleaned out with CLR (calcium lime and rust), otherwise there are no repair parts.
Once the motor begins to slow, it overheats and burns out.
11 years is a good run, so you must have good water or are careful about your water softener.http://waterheatertimer.org/Water-heater-recirculation-system.html
Using the timer and running Autocirc 1 hour a day costs between $11 and $17 per year to operate.
2 hours a day is $22-34 per year.
This includes pump operation and additional time that water heater operates.
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Also take advantage of fixya phone service.
For a price, expert speaks with you over phone while you work on circulation system or any do-it-yourself project.
Fixya is always less expensive than a service call.