Fitting Hydronic Eberspacher

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I am fitting a Eberspacher Hydronic alongside an exisiting Eberspacher warm air heater.

Does anybody know if I can:

1) share the exisiting diesel feed by fitting a Y piece in the existing (warm air unit) fuel supply line

2) share the same transom exhaust fitting by putting a Y piece in the existing exhaust pipe?

I won't be running both units at the same time.

Thanks for replies in advance.

rob
 
1. Yes, for the fuel feed, just T into the existing fuel feed. Its very unlikely to cause any problems.

2. You must not T into the exhaust. The gas from the running heater will back up into the other heater, and may pour nasty fumes into yor boat. Another skin fitting is the only safe way to go when the exhuast gases are concerned.

3. May i ask why you want to have two units? One Hydronic would be able to heat water and provide heating via rads or heater matrix / fans, so why not half the service costs and just use one unit? Keep things simple is always the best way with our floating money grabbing pits.
 
Alex,

Thank you.

Yes it does seem mad to have a warm air and a water heater on board - but the warm air is already there and (preferring anchor to marina) I want to be able to produce hot water on board without running the main engine on idle for hours (which I'm told glazes the cyliner bores). Hence the thinking to fit a water heater. I do plan to fit fan matrices as well as it's a 5kw heater and will be underused just heating up a calorifier of water.

rob
 
All makes sense Rob but what I think Alex was getting at was why not make the installation of the hydronic a cinch by removing the existing unit and using it'sair inlet, exhaust, ducting and fuel connections...................? You may need to swap out the fuel pump an no doubt the wiring loom but overall it's go to make the installation so much easier!

I was really annoyed as I installed a new Airtronic only to find the Hydronic's had arrived.......and as I don't have an engine calorifier but do have pumped water system it would have been a no brainer...........
 
give it a few hours and I suspect it will move from idea to plan......... /forums/images/graemlins/cool.gif

only downside I see is expectations - I would expect it to be a relatively easy substitution; but reality is of course always different!
 
Hi, the wiring loom is different and the DW5 Hydronic has a built in fuel pump where the Airtronic pump is external. Is the Airtronic a 4 or 5 KW? if so, the fuel pipes will be ok, if it is a 2KW (D2), the fuel pipe and tank standpipe will be smaller bore and need to be replaced. The exhaust will be the same diameter (25mm). A good source of heater matrix blowers is Stedall, who supply coach and bus builders.

Peter
 
Rob, I plan to install Hydronic next year on my 39 footer.
Any advice and experience You may have acquired during the installation would be very valauble for me. On my part may I suggest You use John Guest's fast connectors and tubing: I used them in remaking the water system in my previous boat and found them excellent. Of course no connection with the Company.
Cheers
 
Would not a hydronic, via matrices be less efficient in heating air? And possibly use more power (matrix fans) in the process? Admittedly the water is a benefit, but keeping the airtronic may save fuel/batt power in the long run.
Please correct me if wrong... Not that anyone would be afraid to.
Jem.
 
Jem,

Yes, that's been my thought also. I don't know how efficient at heat conversion the fan matrices are - meaning the Ah consumption per Btu produced might be considerably worse than the airtronic.

rob
 
It'd be good to know the facts, I was debating going down the hydronic alley in the future, when my budget's back in order- unmounted my old gas heater today, and not sure I want to replace it with like (Rinnai). Cal too much hassle also (raw-cooled, but don't even go there with the "it can be done").
Jem.
 
I've got the Hydronic with two radiators (single panel / single fin) only - no heating matrix's - with one in the main cabin, and the other in the forecabin. The Eber also heats the water in the calorifier.

The cabin/forecabin get warm enough without any matrix. I had it running during the coldest part of the winter when I was working on the boat - and had to turn them down on the thermostatic valves as it was getting too warm to work!!

Why bother with matrix blowers?? Fit thermostatically controlled radiators.
 
I'm in a similar situation, having an Airtronic system but no means of heating water other than running the engine. I've been giving some thought to this (possibly) crazy idea for water heating:
- given that you can use a Hydronic system to heat air via heater matrices, could it be possible to use an Airtronic system to heat water, again via a heater matrix?

I'm just thinking out loud here, but:
- divert the airflow through a heater matrix, venting the air outside, into the cockpit locker perhaps
- have an electric pump to circulate the hot water through the calorifier coils

Of course there are plenty of obstacles - you would need to force the heater run using the programmer, and I don't know what the temperature of the heated air is, but I can feel a prototype coming on.. /forums/images/graemlins/smile.gif
 
I can see the point in leaving the air heater in place. I have a hydronic and it does take a while to start pumping out the heat (about 10 minutes.) Having said that, I would fit a hydronic again and prefer it to having air only. The benefit of hot water on tap is incalculable.
 
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