teflon tape on sacrificial anode - debunking an urban myth

[wrkg_onit]

I have seen numerous postings to the effect that you should not put teflon tape on the threads of the sacrificial anode for a water heater, as this will prevent the electrical conduction necessary for the anode to do its job. SO, I put about 5 wraps of teflon tape on the threads of my new anode, making sure all threads were completely covered and then some. Placed the new anode in the water heater and screwed it in till it started to offer some resistance, but not yet seriously tightened. Measured resistance anode - to -heater, and lo and behold, 0 ohms. This should not be a surprise - once you put some torque on pipe threads the only thing that can offer any resistance to such torque is metal to metal contact between the threads.

[Tony Hwang]

Hmmm, That's no brainer. Tape fills in microscopic unevenness of metal surface. It is not STRONG enough to prevent metal-metal contact.