Iv'e already posted this on the Seal 26 Forum but I thought I would ask you chaps as well. I'm thinking of fitting an eberspacher type heater on my boat but am concerned about the placing and running the heater and ducting. Does anyone have any advise on this please ?
I'd be interested in that sort of information too.
Dark Star P275 No 36
philip linsell
rascal was fitted with the heater when I purchased, I don't use it often but when it's needed I love it. It's fitted right aft in the cockpit locker with insulated ducting round the stern to the starboard under bunks with 2 vents into the cabin. It warms the cabin in minutes.
Unless my batteries are 100% charged I have to run the engine to get it to start, it uses lots of electricity to fire up. I was also told they don't like red diesel, but as I use so little I run the engine and heater on road diesel anyway.
Just to confirm the comment above, we have been on a canal boat for the last couple of weeks and it was fitted with an Eberspacher heater. It heated the 45 foot boat in minutes and started as soon as we finished a day's cruise with no problems. However, in the morning, we could not get it to start without running the engine first. Once it was going, we could switch the engine off and it carried on fine, but without the engine running, it would not ignite and keep burning. The engineers seemed to accept this as the norm.
peter lowry
I believe the further the distance between the eber and the batteries can cause more drain on amps to start up the heater... It draws a lot of power to fire up and get warm... The same applies with the cooling when u switch it off... It can run for 3 to 5 mins before switching off....
Once it is running it uses very little power,.
My knowledge is quiet limited..
Anyone else who has any more info... Pls ad or advise otherwise
Peter Lowry
We fitted the equivalent Webasto heater on Flamingo having read about low volt starting issues with the Ebber. The Webasto does seem to start regardless of battery state but it appears to draw well over 10A! while it is starting up, less than a minute though. It also seems to draw more current as it powers down. Once running however it doesn't seem to use too much current. But oh boy, when it's running it is well worth it.

Regarding the ducting on the 275 I went through the bulkhead on the port side from the cockpit locker, into the void behind the galley/cooker and then through the next bulkhead to arrive behind the port hand saloon seat back; this was a fiddle but leaves you with a tidy installation. From there I went down into the under seat locker, along the back edge to emerge through the little angled panel in the kick plate right next to the forepeak door. I also tee'd off from inside the port side locker into the void under the hanging locker and then out through the kick plate into the forepeak; again a fiddle but worth it.

You must insulate every inch of the ducting thoroughly or you will lose most of the heat into your lockers and voids.

Hope this helps


The route through the void behind the galley/cooker - does that mean the ducting is close to the coolbox?
Dark Star P275 No 36
Dick, yes it does indeed pass directly behind the cool box. Given that my cool box has never worked it doesn't present me with a problem, it might be a concern if you are using yours.

Martin Watson
Hi Phil. only just saw this post so am answering now. I fitted a Eberspacher to Frith about 4 years back, always starts first time without needing the engine running, even if the batteries are a little depleted. That being said my batteries are rarely very much run down as I have potentially 150W of solar keeping them topped up although only 107~130W available at one time depending on the orientation of the boat to the sun. Also bear in mind I have had a refrigerated coolbox running all the time the boat is in use and that used to use about 25~30Amps/pd. The important thing is to size the cable run from the batteries for the length of cable used. You need to account for the full length from and to the battery and use the tables for 3% power loss not 10% power loss. If you don't have the tables here is a copy of the ones I use and keep in my electrics toolbox; (courtesy of Nigel Caulders 'Boatowners Mechanical and Electrical Manual')

Sorry does not want to let me put an attachment on here. I will send it to you as an email

Martin Watson