Getting our radiators working

[jetzi]

I am trying to figure out why our radiators are not getting hot. We get lots of hot water heated by the engine and the radiators are hooked up to the same calorifier. We have an Eberspacher Hydronic D4WSC water heater, but this is not on at the moment as we don't have the 45W it needs (it used to have a separate battery, but we bought the boat without batteries). It's possible that the Eberspacher isn't working for other reasons - I have heard that they require regular maintenance. We don't really need the Eberspacher right now, as we are running the engine a lot for electricity, but I expect we'll need it if we get the central heating system working.

 

I bled the air out of the rads yesterday, and carried on taking water out of the system which was successfully replenished by the header tank. However the radiators never get hot. There is no pump on the system other than the integrated one in the Eberspacher. Is it necessary for us to have the Eberspacher running in order for the water in the radiators to circulate?

 

Here's a diagram of our whole water system:

[rusty69]

So one coil of the calorifier is heated by the engine. The other coil is heated by the eberspacher. Not sure how the rads would be heated by the engine too. I look forward to the answers though. 

[MtB]

4 minutes ago, ivan&alice said:

There is no pump on the system other than the integrated one in the Eberspacher. Is it necessary for us to have the Eberspacher running in order for the water in the radiators to circulate?

 

Yes.

 

The bit of the puzzle you are probably missing is the water in calorifier that comes from the taps is not the same water contained in the radiators, which in turn is probably not that same water as cools the engine. There probbly two coiled copper tubes inside the calorifier through which the engine cooling water and the eberspacher water flows.

 

7 minutes ago, ivan&alice said:

Here's a diagram of our whole water system:

 

Nice diagram! What did you use to draw it? And is your engine really fitted above the calorifer?  

[Robbo]

The system wasn’t designed to heat the radiators from the engine.  Your only link between the engine and the radiators is the calorfier so using the pump on the Eberspultter will circulate the water around the rads  and the calorfier, but even then don’t expect them to get hot, may be just over cold. ? 

Edited December 2, 2018 by Robbo

[Athy]

Are your batteries fully charged? We have an Eberspacher, and it will spring into action only if the batteries are topped up. Otherwise it just whines pitifully for about 30 seconds and then goes back to sleep.

If in doubt, start your engine before switching the Eber on. If it still won't work, then it needs at least a service.

[Alan de Enfield]

7 minutes ago, Athy said:

Are your batteries fully charged? We have an Eberspacher, and it will spring into action only if the batteries are topped up. Otherwise it just whines pitifully for about 30 seconds and then goes back to sleep.

If in doubt, start your engine before switching the Eber on. If it still won't work, then it needs at least a service.

The eberspacher is wired into a separate supply, and that supply is no longer installed.

So the Eber has no battery to 'spark it into life'.

[MtB]

8 minutes ago, Athy said:

Are your batteries fully charged?

 

If you read the OP, you'll notice he says the Eber is wired up to have its own dedicated battery, which is missing.

 

A most peculiar arrangement if I may say.

[WotEver]

6 minutes ago, Mike the Boilerman said:

A most peculiar arrangement if I may say.

Indeed. Probably installed by someone who didn’t understand battery maintenance. 

[Bee]

Radiators need quite a good heat source (solid fuel stove etc) as they will lose heat into the boat , that's what they are supposed to do. If you connect the engine straight to the rads you will get some heat from them but only when the engine is running and that's asking for a lot of waste heat from the engine. It looks to me as though even if you did get the rads to work they would cool the cal. down to lukewarm in about 10 minutes anyway. I think your only source of heat is the Eber and as its now December I think you need to concentrate on that. Do you have a solid fuel stove? Its common to run rads from that and even if you don't have a back boiler you can huddle around it when it gets cold.

[WotEver]

28 minutes ago, rusty69 said:

So one coil of the calorifier is heated by the engine. The other coil is heated by the eberspacher. Not sure how the rads would be heated by the engine too.

They wouldn’t. 

36 minutes ago, ivan&alice said:

We have an Eberspacher Hydronic D4WSC water heater, but this is not on at the moment as we don't have the 45W it needs (it used to have a separate battery...

I suggest you correct that arrangement, start up the engine, then see if the Eber works. 

[Alan de Enfield]

12 minutes ago, Mike the Boilerman said:

If you read the OP,

Now - that's a novel idea.

[rusty69]

7 minutes ago, WotEver said:

36 minutes ago, rusty69 said:

 

They wouldn’t. 

Well,At least I am now sure

[David Mack]

Your plumbing is not arrangd for the engine to heat the radiators, and even when it is, engine heat will only ever get radiators warm, and only then when the engine is running.

Your first action should be either to get a new battery (and a means of charging it) for the Eber, or probably better, rewire it to run from your main domestic bank.

[Dr Bob]

52 minutes ago, ivan&alice said:

We have an Eberspacher Hydronic D4WSC water heater, but this is not on at the moment as we don't have the 45W it needs (it used to have a separate battery, but we bought the boat without batteries

 

How many Amps is that?

 

 

 

....no, no, no,........only joking!

[Athy]

27 minutes ago, Mike the Boilerman said:

 

If you read the OP, you'll notice he says the Eber is wired up to have its own dedicated battery, which is missing.

 

A most peculiar arrangement if I may say.

Alan and Mike, although he said that it used to have its own battery, he didn't sayt hat it wasn't wired to another battery now.

If it has no battery at all, even a non-techie such as I can have a good guess at why it doesn't work.

[mrsmelly]

fuel........stove.......solid

[Tom and Bex]

44 minutes ago, Mike the Boilerman said:

 

If you read the OP, you'll notice he says the Eber is wired up to have its own dedicated battery, which is missing.

 

A most peculiar arrangement if I may say.

Not that uncommon. When looking to buy our current boat, all Black Prince boats we looked at had it wired this way, as did some other hire boats. 2 batteries dedicated to domestic use, 1 dedicated to Eberspacher, and 1 engine start battery. 

[WotEver]

6 minutes ago, Tom and Bex said:

Not that uncommon. When looking to buy our current boat, all Black Prince boats we looked at had it wired this way, as did some other hire boats. 2 batteries dedicated to domestic use, 1 dedicated to Eberspacher, and 1 engine start battery. 

That makes sense for hire boats. You’re putting the boat into the hands of someone who quite likely has no idea about battery maintenance. They run the domestic bank flat watching TV until the lights go dim but they can still start up the engine and the heating in the morning. For a private boat where the owner (hopefully) looks after their batteries it’s a daft way to wire it up. 

[MtB]

29 minutes ago, Athy said:

Alan and Mike, although he said that it used to have its own battery, he didn't sayt hat it wasn't wired to another battery now.

If it has no battery at all, even a non-techie such as I can have a good guess at why it doesn't work.

 

I think you miss the subtlety of Ivan’s question. He is wondering why the engine does not heat the rads, I think. 

(While the eber battery is missing)

[rusty69]

8 minutes ago, Mike the Boilerman said:

 

I think you miss the subtlety of Ivan’s question. He is wondering why the engine does not heat the rads, I think. 

(While the eber battery is missing)

That is how I understood the question .I think mr Athy is suggesting the OP originally didn't have a battery for the eber,but now he has(possibly)?

Edited December 2, 2018 by rusty69

[Athy]

Obviously MtB, you have specialist knowledge of the mysteries of plumbing, but at least one poster has suggested that the radiators should be heated by the calorifier, not by the engine. That much I DID understand. So if the Eber has no battery, it stands to reason that it can't heat the radiators, and ergo they remain cold - although Ivan hasn't said that they don't work at all, just that they don't get hot.

Edited December 2, 2018 by Athy

[Johny London]

And as already said - the sytem is not designed for the engine to heat the rads. You need to get the ebersplutter going.

[jetzi]

1 hour ago, Mike the Boilerman said:

Nice diagram! What did you use to draw it? And is your engine really fitted above the calorifer?  

Thanks! I used draw.io it's great for these kinds of things. No, the engine and the Eberspacher are in the engine bay, it's schematic

 

1 hour ago, Mike the Boilerman said:

The bit of the puzzle you are probably missing is the water in calorifier that comes from the taps is not the same water contained in the radiators, which in turn is probably not that same water as cools the engine. There probbly two coiled copper tubes inside the calorifier through which the engine cooling water and the eberspacher water flows.

I figured that the water in the radiators was not the same water as the engine cooling water, because a) the header tank implies that the system is separate from the domestic water and b) because the water I bled out of the rads had a touch of oil and a yellowish hue. I presume this water needs to have an antifreeze/anti corrosion additive. However, I thought that the engine cooling water and the rad water would be the same, because I haven't found a header tank for the engine. It could be tucked away in the engine bay somewhere, but the header tank in the diagram is about 1.5m above the floor so I would have thought it required a bit of height. Perhaps the engine coolant is topped up manually through a port inside the engine bay?

However, I thought that the heating alone would cause circulation inside the radiator system - the pipes of the rad circuit leading out of the calorifier do get warm when the calorifier is warm, but only for a foot or so so there's definitely no circulation. Looking at the diagram again and water definitely needs to circulate through the Eberspacher to cause circulation in the rads, so that makes total sense.

 

 

1 hour ago, Robbo said:

The system wasn’t designed to heat the radiators from the engine.  Your only link between the engine and the radiators is the calorfier so using the pump on the Eberspultter will circulate the water around the roads and the calorfier, but even then don’t expect them to get hot, may be just over cold. ? 

OK I see - but if the Eberspacher was on (pump and heating) the radiators would be "worth it"?

 

54 minutes ago, Bee said:

Radiators need quite a good heat source (solid fuel stove etc) as they will lose heat into the boat , that's what they are supposed to do. If you connect the engine straight to the rads you will get some heat from them but only when the engine is running and that's asking for a lot of waste heat from the engine. It looks to me as though even if you did get the rads to work they would cool the cal. down to lukewarm in about 10 minutes anyway. I think your only source of heat is the Eber and as its now December I think you need to concentrate on that. Do you have a solid fuel stove? Its common to run rads from that and even if you don't have a back boiler you can huddle around it when it gets cold.

Ok I see - so seems like the common consensus here is that the Eberspacher is required to make the radiators usable - both for the pump to circulate the water, and for the heat which the engine alone wouldn't manage? The engine provides plenty of almost too-hot water within about 20 minutes of running so I thought that the engine would be adequate to have some impact on the rads. I expect the Eberspacher is a more efficient way of heating our hot water, as well?

Yes we have a Morsø Squirrel at the far bow end of the boat, which heats the front half of the boat (saloon, kitchen and somewhat the bedroom) extremely well, in fact I had to get up last night to let some heat out because it got uncomfortably hot! We don't have a stove with a back boiler. Perhaps given the proximity of the calorifier to where I want the second stove I should consider adding a back boiler as a THIRD option for heating water?

Currently I'm thinking of installing another stove at the far stern end (next to the calorifier). The heat from the solid fuel is unbeatable and it dries the air out nicely. I'm really, really concerned about the condensation we're getting on the exposed parts of the hull. The stern end is half-fitted and I can see the hull, which has a lot of surface rust, and the bilge, which actually has paint that is peeling up due to the rust. It's virtually impossible to keep these dry and being that this is the bit keeping the cut out I really need to find a solution to drying this out, converting the rust and coating it.
 

 

42 minutes ago, Dr Bob said:

How many Amps is that?

45W/12V = 3.75A right?

 

56 minutes ago, Mike the Boilerman said:

A most peculiar arrangement if I may say.

Actually I know this by looking at the original Black Prince spec sheet, which states that there were originally four batteries - a starter, two domestic, and one for the Eberspacher. I don't know exactly how they were hooked together.
 

9 minutes ago, Tom and Bex said:

Not that uncommon. When looking to buy our current boat, all Black Prince boats we looked at had it wired this way, as did some other hire boats. 2 batteries dedicated to domestic use, 1 dedicated to Eberspacher, and 1 engine start battery.  

Ah, just as I was typing exactly this!
 

To clarify, the Eberspacher is off, I know it's off, but I thought that the heat alone would cause circulation through the rads. I also thought that heat would transfer to the rads circuit effectively inside the calorifier - but I realise now that I'm going to have to get the Eber on. In order to do that I'm going to have to upgrade the domestic battery supply - at the moment I have only one 110Ah battery. I am still researching and trying to decide between lithium ion, lead acid, gel and the other battery types. Wanted to live aboard for a few months and get a feel for the pain points.

 

Anyone know anything about servicing an Eberspacher? ?

[rusty69]

13 minutes ago, ivan&alice said:

However, I thought that the heating alone would cause circulation inside the radiator system - the pipes of the rad circuit leading out of the calorifier do get warm when the calorifier is warm, but only for a foot or so so there's definitely no circulation

No,that is just caused by the hot water heating the eber coil in the calorifier. There is nothing to circulate the water.

Edited December 2, 2018 by rusty69

[Robbo]

5 minutes ago, ivan&alice said:

OK I see - but if the Eberspacher was on (pump and heating) the radiators would be "worth it"?

If the ebersplutter was working the your rads would get hot (or should do), so yes “worth it”.   If you just have the pump on (but the eberspultter not heating) so just circulating the water around the system then it would use the heat in calorfier to heat the radiators but will be not efficient in doing so.

Edited December 2, 2018 by Robbo