Calorifier to high?

[roly_voya]

Fitting one of these things to the new engine but the directions say lead the piping level or downhill - only the top of the engine is only 1ft above the floor so that would mean mouting the hot water tank in the keel!! Its going to be about 1ft above top of the engine.

Anyone come accross a solution to this problem, can you fit a remote header tank?

 

[jerryat]

I had a similar 'problem' with my installation many moons ago. If, as you should do, you are installing a small 12v pump in the calorifier/engine circuit, the problem is solved by ensuring that the pump is placed on the INPUT side of this circuit.

So, hose from engine to pump, then from pump to input (top connection) of calorifier, then output from calorifier back to engine. As long as you ensure that the PUMP is placed where it is always 'flooded', you will not experience airlocks.

You'll also get very hot water, so be careful!! /forums/images/graemlins/smile.gif

You probably know which type of pump to install, but if not PM me and I'll try to help.

 

[Cloven]

Don't doubt your comment about the installation directions, but when I bought my boat, the calorifier was sited directly above the engine with pipes obviously going "uphill" and it works fine. This is on a fresh water cooled Yanmar and the outlet to the calorifier is adjacent to the freshwater pup so I guess that is what circulates the water. Certainly there is no additional 12v pump in the circuit.

One other thing, I have added an expansion tank in the system to even out the effect of the expansion of the water as it heats up.

Hope this helps.

 

[Strathglass]

The problem is that you will have air in the calorifier.
What you need to do is to vent the highest pipe in the calorifier path to let the air out, then close the bleed valve

Or, as you say,
The best way is to put a small header tank above the calorifier with a radiator type pressure cap on it and use this to fill the engine water system. This will get rid of the air.

Iain

 

[Cloven]

Good point Iain, should have said that there is a header tank for the engine fresh water systen higher than both engine & calorifier.

 

[Strathglass]

In that case you only require to bleed the air out of the calorifier path. As long as the engine filler is still higher then you should be ok.
Possibly you can raise the highest feed pipe at some point, cut the pipe at the highest point, then put a bleed screw there.

Iain

 

[Danny]

As Iain has pointed out the main potential problem with the calorifier being higher than the engine header tank is that, even after bleeding air from the heating coil, you may still have a problem with air collecting there over time.

I put together some notes about a similar installation that I did on my boat. In my case, although the calorifier is above the header, I don't have a problem. There seems to be sufficient coolant flow to sweep any air pockets out of the coil and back to the header.

You may find my notes useful. They're here.