To use a standard tap may actually remove portions of the existing threads as well as cut new threads something to be avoided in a water heater tank fitting.
Rv water heater anode thread size.
Before you consider re tapping the threads re check to make sure you have the right sized anode rod.
I reached out to my contact at suburban and they advised me that your water heater has a 3 4 npt national pipe threading and it has 12 threads inch.
You ll need a 3 4 inch npt thread chaser since the replacement anode will likely have a tapered pipe thread.
Plumbonline have put together a comparison table see below to make selecting your anode as simple as possible as in most cases the owner manual for your hot water service does not detail the size.
Ozek rv water heater magnesium anode rod with ptfe tape compatible with suburban and mor flo water heater tanks 9 25 length npt threads 2 pack 4 8 out of 5 stars 853 11 99.