Calorifier

donm

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Fitted a calorifier to my Beta engine last winter. After bleeding all of the air out of the supply to the heating coil there is still insufficient flow to heat the water quickly - the general expectation seems to be 20 minutes, but even after 30 minutes of motoring the water is only just tepid. I can increase the size of the pipework a little but am also considering adding a pump to improve the speed of the flow to the coil. Anyone had similar problems/solutions?
 
Thanks for this. The flow and return pipes to/from the coil were finally hot enough but took a long time to get there - around 15/20 minutes. Could be that the thermostat took a long time to open?
 
When I fitted mine this last spring, I had the same problem on a Volvo but it was an airlock. The pipes were getting hot after 15/20 minutes but really was convected heat with no circulation. Once I got the air fully out (there were a couple of false dawns) it was fine. I back filled the pipes and coil with both off and then put them onto a pre-warmed engine and bingo.
 
When I fitted my new Beta in the spring, I just connected up the hoses as recommended and it worked fine after only about 10 minutes with the engine running. The calorifier is about on the same level as the engine and maybe this makes a difference.
 
Two bits of my experience, one already posted.

Airlocks can be very difficult to remove; it used to take me an hour each season to refill my system. Backfilling with a hosepipe usually works but it can be a wet business.

Ensure that the connections are the right way around. Connecting the hot supply to the bottom port instead of the top one will arrest flow completely.

I don't know how your arrangement works but it is best practice with a raw-water cooled engine to circulate water around the engine cooling jacket using an external pump. They are available form T.Norris, amongst others. I can provide a part number if this is what you decide. With a fresh-water cooled engine the circulation pump will be perfectly adequate unless your calorifier is more than about 3 metres horizontally from the engine. In this case it may need a booster pump. Systems in which there is a considerable vertical difference between engine and calorifier will work OK but it may take some time to establish the flow. Again, a booster might help.
 
From personal experience I would second the reply about getting the connections the right way round-if you have longish pipe run going through various lockers its easy to get confused about which is the inlet & which the outlet pipe is-if you do you'll get the symptoms you describe.
 
just out of interest do you use antifreeze in your heating loop, reason i ask is mine has it added, but my worry is failure of the coil and the antifreeze making its way into the domestic water system.
 
Yes, I have anti-freeze in the coolant. The coil is continuous copper (same as in a domestic system) so the risk of contamination is very small unless the coil has an inherent defect.
In any event I never drink tank water, hot or cold!
 
Yes I do-its freshwater cooling and that feeds the calorifier so as far as I can see you have a choice between running the engine w/o antifreeze or the slight risk of contaminating the domestic hot supply. Since antifreeze does a lot more than keep the frost off (at least if the blurb on the tin is to be believed!) I go with keeping the a/freeze in the system.
 
Domestic water pump should run at a highter pressure (15-20psi) than the 'fresh' water system on the engine (generaly around 7 psi) so if the coil in the tank did give out you would be more likely to empty your water tank into the boat via the relief valve on the header tank that contaminate your fresh water!!
 
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