Do I need a twin coil calorifier?

Sy-Revolution

Sy-Revolution

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Hi folks,
I'm panning to fit a calorifier this winter and may want to add a water heater (Webasto/Mikuni type) in the future. Will I need a twin coil calorifier or can I fit the water heater into the same system as engine heating and go for a single coil? I'm sure I'd read in some Webasto blurb that they can be used to pre-heat engines in winter so I assume it would be ok.....

Cheers,

Crispin.
 
I think you would be better off to fit a twin coil calorifier with an immersion heater.

I had a single coil calorifier and could only get hot water and radiator heating from the Eber, with the engine waste heat being just that - wasted.

I can now get hot water from the engine, or hot water and radiators from the Eber. When in a marina I can get hot water from the immersion.

Fit a twin coil and you have the option one way or the other.
 
Agree with philip-stevens above, even if you are only just thinking about adding Webasto/Mikuni/Eber type water heating at this stage then having a twin coil will give you that option in the future.

One point, think carefully about your plumbing layout so that if and when you come to add the extra heating source, you can access the inlet/outlet points on the calorifier easily. If they are difficult to access you could make those connections now to a point where you can connect in to them in future. No water will run through this pipework so you you only need cap it to keep dirt etc out.
 
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Thanks, that makes good sense but is it nessesary to have two separate circuits, if indeed I wished to use the Webasto/Mikuni to pre-heat the engine as well as warm my domestic hot water?

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Taking your post literally - then you could get away with one circuit.
"Get away with" means that there would be no damage but you should consider:-

Your wasting heat in heating the engine as well as the rest of the boat. These heaters are generally small capacity, so warming the engine would take heat away from where you need it.

I think there may be "opportunities" with the circulation -
The take off for the calorifier (what would ordinarily be for the vehicle cab heating) has normally an indifferent flow, and I think the added drag induced by the Webasto pump not running might stop any flow altogether.

Similarly you may reduce flow when using the Webasto on it's own.

How are you going to heat the boat - I assume with radiators of one type or another? Webastos / Miking are either water or air, but not both (?). If I'm right when you run the engine it will heat the boat as well - IN SUMMER.

Twin coils are not astronomically expensive, and IMO it's not worth the extra complication in trying to get the thing to work under all circumstances.
 
Youy gave up without a struggle...

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Perfectly logical argument, accepted. A twin coil it is.

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Those awfully nice people, just down the road from you - (ASAP) did my last one, and I thought the price was competitive, probably a bit of a shocker at today's prices, though.
 
I bought mine earlier this year from SureCal. Very helpful people, and a good-value product. Unfortunately, their website isn't working properly at the moment!
 
I disagree with the logic behind most of the posts on this thread.
A twin coil calorifier will allow the engine coolant circuit to be separate from the eberkuni circuit.
A single coil calorifier with an eber/mikuni water heater will allow the waste engine heat to be used for heating (radiators/matrices) as well as water heating, if the engine is generating enough waste heat. (many diesels don't generate that much waste heat unless being worked, hence eber's appearing in Freelanders etc). Being a single circuit it also allows the engine to be preheated if you wish.
Whether the radiators are heated or just the calorifier is easily selected with a valve, in either case.
Having the engine heated can be beneficial in that it increases the heat capacity of the system, reducing the tendency of the eber to cycle on and off a lot. The engine tends to act like a storage heater, slowly releasing heat into the boat.
The down side of single coil system is that one fault in the heater plumbing disables the engine. Also the large volume of water can cause the engine's coolant overflow/expansion arrangement to be overwhelmed. If I were starting from scratch I think that would be enough to push me towards a dual coil system, if the cost diffrerence was reasonable. It took me a while to get my single coil system to work properly, a dual coil should be simpler. But I think it's important that the coil on the eberkuni side has enough surface area to heat the water rapidly, or the eberkuni will tend to short cycle, which is noisy, inefficient and bad for reliability.
So I would want to know about the surface areas of the heating coils.
Hope that helps,
 
i also had a twin setup with the engine on one coil and the eberspacher on the other, as said already the eber used to fire up and shut down every 2-3 mins on my setup this was flattening the batterys and was fairly anoying, i changed over to a single coil still using both but looping together.
It does help to have a nice warm engine, starts like a dream
 
Firstly are you having problems starting your engine when cold, if so why not sort that out. Even the rattle old Leylands I took out would start OK using the standard fitted heater plugs.

The only reason I would fit a twin coil system would be if I was running a generator, the I would connect one coil to that and the other to the motive power engine. I would not interconnect both engines to use the same coil in case of leaks bursts etc. A one coil system could be used if connected through a valve bank and bypass.
 
Sounds like I'm not the only one who's worked out a few of the subleties the hard way! I'm not aware of any written guidance to rival the knowledge on this board, which tends to get buried by the volume of posts and poor search system. Is there any good info on the web anywhere? or archive mag articles?
I was not impressed with the info that came with my eber kit.
Cheers,
 
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