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Hot water tank (calorifier) removal


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For reasons I might discuss in another thread I have to remove the hot water tank (calorifier) from our Farr1220. On the tank there are 4 inlets/outlets as follows:
Potable Water (the water to be heated):

  • Fresh (cold) water in
  • Fresh (hot) water out

Engine Water (the water doing the heating):

  • Engine water in
  • Engine water out

The first two are easy when it comes to disconnecting. For the first the freshwater tanks will be shut off before disconnecting for the second Ill lose some water into the bilge that is sitting in the pipes between the tank and the hot water taps but that should not be much.
 
For the second two, Im a little more cautious. The water from the engine comes from the fresh water cooling circuit on our VP2003T. See attached photo for the two connections on the engine that lead down to the hot water tank.
 
I do not want to disconnect the pipes on the tank and end up draining all the coolant out of the engine (the hot water tank is lower than the engine header tank). Should I be disconnecting at the engine end first? Note the two outlets on the engine are also slightly lower than the level in the coolant header tank. Once disconnected and caps put on the inlet/outlet on the engine will the engine still be ok to run?

 

Also, I need to think about the reinstall later and making sure there are no air lock issues.

 

Thoughts?

hotwater.jpg

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Neil, you will lose some coolant. Unavoidable. It will drop to the heat exchanger level. No problem, except the mess. Just top it up when refitting. Above the coolant tube on the exhaust riser is a brass plug. Open that when refilling to remove the airlock, or better yet take it out and put it where the barb to the header tank hose is - swap them around to avoid airlocks in future.

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Tank out with surprisingly little mess :-)

 

Now I'm setting up a test in my garage to determine the source of our problem. There is a leak from the tank which I thought might have been the relief valve but now think the tank itself is f**ked. 

 

Any advice on buying a new tank/calorifier?

 

NoTank.jpg

TankTest.jpg

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Yesterday I did just that. The leak seems to be coming from the tank itself in the area of the white stuff (which I presume is some form of corrosion). The comedy moment was when I realised - too late - that the insulation inside the lining was thousands of bean bag beans. It took some time to get control of the garage back from the tsunami of little white balls!

 

Some pics and you can just about see the leak in the video:

 

Priscilla, thanks for the link, I'll contact those guys and see what advice they can give, not much hope for the tank though I think. 

 

https://vimeo.com/299520385

20181108_093039.jpg

20181108_093053.jpg

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Yep, its stuffed. What type of, and what % of corrosion inhibitor was in the cooling system? That's failed due to corrosion...

 

The engine coolant will have whatever they put in at the last service. However, I think the problem is on the fresh/potable water side that goes to the taps in the boat which will be just pure water from the marina tap. 

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New tank on order so hopefully all put back soon.

 

Neil, you will lose some coolant. Unavoidable. It will drop to the heat exchanger level. No problem, except the mess. Just top it up when refitting. Above the coolant tube on the exhaust riser is a brass plug. Open that when refilling to remove the airlock, or better yet take it out and put it where the barb to the header tank hose is - swap them around to avoid airlocks in future.

IT, when I come to plumb back in what should I use to top up the engine coolant? I was thinking just plain old de-mineralised water same as I'd top a battery up? Or is there something else I need such as a corrosion inhibitor? Plenty of coolant still in there so only a top up really.

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Yep, should be with corrosion inhibitor. Buy some ready to use from repco or super cheap, automotive stuff is fine. If your coolant hasn’t been changed for some time, change the lot. And, if it’s the turbo version, don’t forget to bleed the air from the little brass plug above the water tube by the exhaust outlet on the manifold.

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Yep, should be with corrosion inhibitor. Buy some ready to use from repco or super cheap, automotive stuff is fine. If your coolant hasn’t been changed for some time, change the lot. And, if it’s the turbo version, don’t forget to bleed the air from the little brass plug above the water tube by the exhaust outlet on the manifold.

 

IT a quick question: The project is making progress albeit in a fiddly, awkward and everything difficult to get at way. Installed the new tank and re-plumbed the engine (the freshwater for the taps still requires some further tricky plumbing). Once the engine was hooked up I unscrewed the brass plug marked in the picture and filled the header tank until water poured out of the hole then plugged it back up again. Is that all I need to do in terms of bleeding the coolant or will I get further air locks once I run the engine? Presume I just run at idle and loosen the plug until only water is coming out? I am a bit uber paranoid about the turbo not being cooled properly as I'm picking that is pretty important. I'll start the engine once I've got the rest of the plumbing done over the next few days.

20181125_125115.jpg

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yep, thats the bleed valve. All you need to do is what you've done. A good modification is to take the header tank outlet from the thermostat housing and put it in the bleed valve hole - swap them over . Then no bleeding is required.

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