Stephen Jeavons

That's interesting, so a well known boat builder is routinely using 10mm microbore against advice and presumably not having problems. Well, like I said previously, I was only contemplating dropping to 10mm for the front two radiators and would feed the manifold for these with 22mm pipe. The use of distilled water sounds like a good idea too. I still have a pile of other stuff to do before the central heating rises to the top of the to do list but will report back on how it all functions if I elect to go ahead with the 10mm pipe Thanks everyone for the advice and comments

Hi Mike, As it happens, the installation manual I have is the one I got when I bought the boat and unfortunately it relates to the fitting of the unit to a motor vehicle. No 15mm pipes mentioned of course. if anyone has a Marine version of an installation manual for a Eberspacher D5W to share, I would be grateful. Anyway just to clear any misunderstanding, the piping to and from the Eber is 22mm. Ditto to the rear radiators and calorifier. I only wish to use micro bore on two front radiators not the entire system. I hope that makes sense.

The reason I'm considering it is because I don't have enough space for a pair of 22mm or even 15mm pipes. I can buy a coil of plastic or copper microbore and thread it where it needs to go without having to join it. My shore-powered electric boiler uses a standard domestic mains circulator. However the Eberspacher will be using its own so therein lies the gotcha. The mains system may work fine with the microbore but the diesel powered one with its 12v pump may not. Both heat sources are plumbed in parallel with isolators to use one or the other depending on whether we're plugged in or cruising. It's only the two rads at the front of the boat that I'm considering feeding with microbore due to space/access restrictions through the kitchen. Bathroom, engine-room, back cabin and calorifier are all 15/22mm. Unfortunately those two radiators are furthest from the heat source which is in the engine room. Will do the radiator calculations and have a re-think. My original query was just to sound out whether anyone on the forum is using microbore on their boats for whatever reason. So far the answer is NO! Thanks very much for the insight guys.

Yes, interesting that. Strangely enough, all 3 of the houses I've owned and at least 2 that I've rented have all had microbore and I too never had an ounce of trouble. I even retrofitted restored old iron radiators in 3 of the rooms in one (they were great) without an ounce of trouble. I guess regular maintenance and ensuring that the appropriate rust inhibitor is added is the key.

Thanks for the comments all. One drawback I see is the linear nature of a narrow boat which doesn't lend itself to having a central manifold and feeds to radiators radiating from it in all directions so may have to rethink this one

Hi All, Due to a school-boy error (pressure from elsewhere to re-fit the interior in quick time) I've found myself needing to re-install the central heating on my 70' narrow-boat with limited access to run conventional pipework to radiators. Having owned a number of domestic properties which had microbore radiator plumbing, I was exploring the option of using it (the later plastic variety, not copper) on the boat. Anyone have experience, good or bad of doing this? It would solve my problem as no joints in awkward places would be required between manifold and radiators. Stephen

Folks keep saying that the Diesel heaters require regular servicing. Could I ask which bit gets serviced, what is done and how difficult is it to do DIY-wise? Is it the glow-plug that cokes up, the combustion chamber or exhaust? How difficult is it to service? I'm re-commissioning an old one and would like to do the job myself. Stephen