The Bradford White AeroTherm heat pump water heater that Came With The House™ has been running for three years. Based on previous experience with the same City of Poughkeepsie water, it was time for a look at the anode rod.
Which, as always, required the Greatest Ratchet with a foot of extensions getting the 1-1/16 inch socket down to the rod:
Remember to:
- Turn off the water heater power
- Shut off the inlet and outlet valves
- Open the drain valve to relieve the tank pressure
- Only then loosen the anode rod
Seeing the first few inches justified extracting the rod:
Due to low overhead clearance and inauspicious pipe locations, I had to hacksaw the bottom third off to extract the rod:
With the rod out, draining a few gallons of water into a pan didn’t produce any notable gravel, so I didn’t do a complete flush. Much to my delight, the drain has a ball valve!
Given that this is a fancy water heater and I no longer regard anode rod maintenance as a fun-filled activity, I installed a Corro-Protec powered anode rod for cathodic protection without all the crud:
The wall wart proclaims 15 mA with a green LED indicating it’s hard at work:
The data plate on the back reports 24VDC 15mA, but, being me, I poked at it with a handful of resistors:
The electronics could be as simple as a 24 VDC wall wart feeding a 425 Ω series resistor and a transistor switch lighting the LED for currents a little over 6 mA.
A quick ohmmeter check shows the powered rod electrode is open-circuit with respect to the tank, as it should be without much applied voltage. Applying +24 VDC from the wall wart drives 15 mA into the water: the rod is hard at work.
I’ll take a look at it in a year or so just to see what’s going on in there …
The Smell of Molten Projects in the Morning 
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