I don't think so. It says disconnect the WH power during install.
On the Ebay page, it says
"For maximum savings, it is recommended that the existing water heater be disconnected."
But, using the heating elements might be required if you have company and a few more folks need to take showers..
Seems like you could set the A7 to 125F and set the heaters to 110F..
When the A7 wasn't keeping up with demand, you pay extra..
There is a port on top where the Anode screws in. I'm assuming it's there.
Maybe I'll pry off the plastic cap, cut out the insulation and remove the Anode for inspection.
I think it might need to be well grounded to the tank, so maybe Teflon tape might not be the best way to re-install it..?.
The A7 brackets attach to the water in/out pipes (nipples).
I've already pulled the hot & cold nipple (PITB). I will replace the hot with the special brass nipple from the A7 kit.
The cold nipple is short and has flow restriction (small check-valve), so I'm going to replace that one with a 6" iron nipple.
Using the short (stock) cold water nipple causes the U-bolt clamp to rest
on the connecting cold water input pipe..
Since I'm going to use 3/4" Pex, the extra tall nipple will allow the clamp to rest on iron. (It can be real tight).
Here's my test fit photo.