Yanmar coolant change - with calorifier

[searocket]

We have a Yanmar 2YM15 on our sailing boat and there is a coolant feed to a calorifier for the boat's hot water.
I am new to engine maintenance and want to change the coolant. I dont know when this was last done but it is more than 2 years ago. I have found good videos on doing this, except they gloss over the calorifier.
Do I need to do anything to specifically drain the coolant from the calorifier - or is it sufficient to use the drains on the engine?

 

[PaulRainbow]

We have a Yanmar 2YM15 on our sailing boat and there is a coolant feed to a calorifier for the boat's hot water.
I am new to engine maintenance and want to change the coolant. I dont know when this was last done but it is more than 2 years ago. I have found good videos on doing this, except they gloss over the calorifier.
Do I need to do anything to specifically drain the coolant from the calorifier - or is it sufficient to use the drains on the engine?

There will be a relatively small amount in the calorifier, it's just a coil on the fresh water. Draining the engine will be sufficient, use 50/50 water and antifreeze, if using neat antifreeze.

 

[tross]

It is recommended that you use distilled water rather thn tap water.

 

[VicS]

We have a Yanmar 2YM15 on our sailing boat and there is a coolant feed to a calorifier for the boat's hot water.
I am new to engine maintenance and want to change the coolant. I dont know when this was last done but it is more than 2 years ago. I have found good videos on doing this, except they gloss over the calorifier.
Do I need to do anything to specifically drain the coolant from the calorifier - or is it sufficient to use the drains on the engine?

It will depend on the layout of the system. Probably best to take off a hose to be sure its drained. You will probably have to vent the air when you refill.

A long life / OAT antifreeze is specified ( hopefully it has not been filled with a conventional type)

As above dilute with distilled water unless your tap water is low in dissolved solids ........ or buy it ready diluted.

Due to the risk of contamination with seawater do not extend the change interval even though it's a long life antifreeze.