Eberspacher Water heaters

Richard10002

Richard10002

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Hi,

Moody 44

I'm finding that the calorifier does not provide enough water for a reasonable shower, (engine run for hours at 1300 revs), whereas it provided more than enough when we were in Madeira a couple of years ago. Presumably, this is because the cold water is colder here than it was in Madeira, or could there be a problem?

I've been looking at these eberspacher water heaters, which seem to be designed for liquid central heating, and hot water via a calorifier. The smallest ones seem to provide a flow of 900l/h.

http://www.eberspacher.com/hydronic4.php?section=waterheating

I am wondering if one of these could be attached to the calorifier only, and if it would keep up with me having a shower, in terms of replenishing the calorifier with hot water, (a bit like a combi boiler). If I can find the money, it would probably be worth the £2K or so, if we can find space for it under the rear bunk.

Kind Regds

Richard
 
Does the engine run at normal operating temperature ? It could be a faulty thermostat.
Is the hot water temperature at normal temperature or is it cooler than normal ?

The eberspacher would probably be OK. What is the holding capacity of the calorifier ?

I don't think that you can use it as a combi boiler, i.e. generate instant hot water as this would need a lot of power (fuel) and the hot water in a combi boiler is heated directly whilst the eberspacher uses indirect heating
 
I've got an Eberspacher Hydronic (the type you are talking about) in our boat. It was heating both radiators (via thermostatic valves) and the calorifier, and gave us enough hot water to have a shower from the 25ltr calorifier.

The only problem was, and not the Eber, was that we got no hot water from the engine when running. This winter I have fitted a new calorifier with two coils and an immersion for when we may go alongside with shore power.

The new calorifier gets heated water from the Eber and/or the engine when running.

The twin coil/immersion calorifier was from ASAP Supplies
 
If it worked before it should work now even in the arctic.Have you felt to see if the top pipe coming from the engine is hot where it comes out the engine.if its hot there (dont burn your hand) travel your hand down the pipe and if it gets cooler you have an airlock.Take off the top pipe at the engine fill with water A/Freeze mix put back and run engine,should be OK.One of my previous boats was a sod to get the water circulating after draining the coolant ,I had to run at about 2000rpm for a while then it was ok for rest of time.
 
I have the same arrangement as philip-stevens - an Eber hydronic heating both the boat and hot water. It has valves that allow either just the radiators or just the hot water or both to operate. So, I see no reason why one could not be installed just for hot water.

We find that if you have been running the engine through the day then there is enough hot water for a shower/washing up etc at the end of the day but it has cooled down by morning. Also, if we have spent most of the day under sail (which is the general idea!) then again the short engine use just for anchoring/mooring is not enough to heat up the hot water. This is where the Eber comes into its own.

Incidentally, as philip says, if you still want hot water from the engine, you will need a twin coil calorifier. This is what we have in out set up and it works fine. It also has a 240v immersion heater for marina use.

Hope this helps
 
[ QUOTE ]
Does the engine run at normal operating temperature ? It could be a faulty thermostat.
Is the hot water temperature at normal temperature or is it cooler than normal ?

"The hot water is roasting, as it's always been."

The eberspacher would probably be OK. What is the holding capacity of the calorifier ?

"Not sure until I get back to the boat on Tuesday - it's the original on a Moody 44 as far as I know."

I don't think that you can use it as a combi boiler, i.e. generate instant hot water as this would need a lot of power (fuel) and the hot water in a combi boiler is heated directly whilst the eberspacher uses indirect heating

[/ QUOTE ]

That's what I thought, but was confused by the 900l/h, or 15l/m, which would be more than enough to keep a hot shower going.

Many Thanks

Richard
 
I may be mistaken, but I think the 900l/hour is the water that circulates through the heating coil in the calorifier. As this water is circulated it is partially cooled by the water that it is trying to heat. The return temperature back to the eber will be only a few degrees cooler than the temp of the water going to the coil. Over a period of time the heat is transferred to the water in the tank.

If you run fresh water into the eber, first of all the eber has to warm it from ambient temperature, this requires a lot of energy (fuel). If you look at the size of the burners in a combi boiler you will see.

The spec for the Hydronic 10 is

Heat settings Power High Medium Low
Heat flow watts 9500 7500 3200 1500

If the 'heat flow' figures refer to actual heat output, then they appear to be comparable to a standard domestic electric shower which is around 8KW.

The second issue is that if you pipe fresh water into the eber, it will eventually scale up with calcium deposits e.t.c. further reducing the efficiency.

IMHO, if you want to use the eber, it would have to be run in the same manner as the two previous posters (philip_stevens and davewarburton) have suggested, i.e. use a calorifier with twin coils.

I think that it is worth pursuing and diagnosing the problem with your exising setup, it could be something fairly simple and cheap to repair,
 
if you are running the engine just to heat the water, it wont, or not very well, you need to put it in gear to put a load on the engine so that it runs hotter quicker.
stu
 
[ QUOTE ]
if you are running the engine just to heat the water, it wont, or not very well, you need to put it in gear to put a load on the engine so that it runs hotter quicker.
stu

[/ QUOTE ]

Stu,

The hot water gets roasting hot, and I'm reasonably sure that the calorifier is full at the start of the shower.

The problems seems to be either:

mixing with colder "cold water" than in hotter climes uses up the hot wate quicker, or the capacity of the calorifier has reduced, (calcification?).

I'll have a better idea when I get back on the boat on Tuesday - hopefully I can find the make, model and capacity of the calorifier, and I may run the hot water into a bucket until it gets cold, and compare the capacity with that stated.

many Thanks

Richard
 
R
my bene 351 has a bog std calorifier and we can ususally get 2 -3 showers out of it, however they are wet first, then soap and then rinse, usually about 1 - 1.5 galls in the shower tray per shower.
S
 
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