Replacing anode in the calorifier

[tillergirl]

Has anyone any experience of whether this is needed if you don't use the immersion heater?

I have a spare anode but I cannot withdraw the old one with the tank in situ. Releasing the tank is possible but not the easiest task in the world.

Thinking this through, I have never used the immersion heater as engine heat has always been sufficient until now and the swtich has always been off at the breaker. Is it likely the anode will waste just using the engine circuit to heat the water. The instruction manual says "The anode has to be replaced each year" and is "there to protect its internal surfaces and the whole plant in general against galvanic corrosion (natural electrolysis)".

Any views anybody please?

 

[VicS]

I don't see that using or not using the immersion heater has any relevance. The anode is there to counter the effects of galvanic corrosion.

Presumably your calorifier is fed with hot seawater from a directly cooled engine and the anode is in the raw (sea) water side.

A calorifier running on a freshwater/antifreeze mix from an indirectly cooled engine should not an anode although the seawater side of the heat exchanger might.

 

[tillergirl]

The calorifier is fed freshwater/antifreeze mixture from the heat exchanger - no sea water goes near. Hence my question. The instructions make no distinction between direct and indirect cooling. The anode (magnesium) is in the domestic water to be heated.

 

[VicS]

If the manufacturers fit one on the "domestic" side then it must be made of materials which they think will require cathodic protection.
Magnesium is pretty reactive so change it!