Vitocell 100 CVA 450 Hot Water Maker Maintence

[zich6]

I have a 6 year old CVA-450 hot water maker and I'm planning to do maintenance.  Per the manual, 2 years ago I pulled the consumable anode, 7819653, and since it had minor holes, I scaped off the calcium deposits and replaced it.  Now, I need to know the following:

1. How corroded does the anode have to be until it needs to be replaced.

2. Does the tank need to be drained and flushed and if so, what's the best way to accomplish that.

3. Is there anything else I need to check or do?

Thanks.

[zich6]

Please help.  Thanks.

[MichaelN]

A few holes are no reason to change the anode. I would say when 2/3 of the material is gone.

As the anode is always mounted below the water level, the water must be drained beforehand - otherwise it will get a bit wet in the cellar...

Cleaning with citric acid and wet vacuum cleaner is recommended (if required)

You will need new gaskets.

[zich6]

Ok, when I checked it 2 years ago, I followed the Veissmann procedure by pulling the anode from the top, so no need to drain the tank.  That's why I asked if the tank needs to be periodically flushed.  Thanks so much for the great advice on the anode. 

[MichaelN]

OK, the anode is mounted on the top. Then you not need to drain the tank.

[zich6]

Ok, so no requirement to periodically flush the tank?