Refitting a heater
Fitting a diesel-fired air heater is something you only want to do once – but how and where it’s installed can prove vital to its long-term condition, as David Parker found out
How and where a diesel-fired air heater is installed can prove vital
When you have been fortunate enough to have had a decent boat heater on board, it is a luxury you are loath to part with. As someone who is more than happy to do ‘basic’ for most of the time, I must also admit that when I bought a boat with a heater I was looking forward to things being a bit more comfortable, particularly over the winter months.
However, there was a snag. When I bought the boat, the surveyor immediately pointed out that he thought the Eberspächer D1LC heater had been put in a bad place. Also, it only had one output duct which was in the cockpit, leaving the cabin unheated. Nevertheless, the unit itself seemed to work efficiently when we briefly tried out on a sea trial one sunny day.
Fast-forward to after we became the owners and tried the heater out one chilly day in the Solent. After about 10 minutes a peculiar and rather unpleasant light smog seemed to envelop the cockpit. Initially as we motored along this wasn’t too bad, but the white fug thickened when we moored up. I turned the heater off, the covers went up and the fresh, chilly air was welcomed. Just as well, I suppose, that there was no output in the cabin, because that would have been fugged up as well. (It still always confused me that there was a heater installed which would heat the semiopen cockpit of the boat but not the cabin!)
A flawed installation
After a bit of research, I thought the smokiness could be due to condensation absorbed by the exhaust lagging, or old dust in the air ducts which was burning off; hopefully this would clear after several uses of the heater. Things marginally improved as I used the heater a few more times; but still, after 10 minutes with the heater on, the localised smelly grey fog appeared, and felt like it was doing you no good at all. You could still use it, of course – if you had the wheelhouse windows and the cover open – but that rather defeats the point of having a heater in the first place. The result? The heater has lain dormant, and it has nagged at me ever since to do something about it.
The reason I was reluctant to tackle the job was the thought of the work involved. One look at the heater wiring was enough to make you come over light-headed without even ingesting the fumes. It looked like a tangle of multi-coloured plastic spaghetti that shouted ‘back off’ every time you opened the locker. The other thing was the position of the locker containing the heater – bang in the centre of the cockpit sole above the bilge, where corrosion could thrive like mushrooms in the dark. True, the drain holes in the access frame had been blocked with sealant so water couldn’t get in… but aren’t drain holes supposed to, well, drain?
I can see why the owner had then chosen to put the heater in the locker under the cockpit sole, because it offered the simplest installation – albeit one in the wrong place. The lessons learned from a flawed installation are also definitely worth bearing in mind when it comes to installing a new heater. This isn’t like putting a heater in a vehicle or caravan. On a boat, the location will be critical if you want to prevent long-term corrosion affecting vulnerable parts of the system. Also, how you plan the installation will affect both the efficiency and maintenance of the unit.
Before starting the job I had been along to the Eberspächer stand at the Southampton Boat Show to do a bit of homework on heaters, and Peter Collard from the company was very helpful. When I contacted him after the show, in addition to the advice he offered he also kindly looked up the records and told me that the heater had been fitted by the boat owner in 1995.
Methodical approach
With an old installation, my concern was getting it out 20 years after it had been fitted under that cockpit sole locker without damaging it. Also, if I had a choice I would always far rather install new equipment from scratch. (For fitting a new heater, see PBO September 2016 for the installation of an Eberspächer D2 on editor David Pugh’s co-owned Contessa 26, Red Dragon.) In my experience, trying to upgrade or move an existing piece of kit someone else has fitted inevitably results in some hidden surprises along the way, so a methodical (indeed, almost surgical) approach is required.
Despite being in the wrong place, the Eberspächer heater was still an expensive piece of kit – and it worked. In an ideal world, if I could get it to produce the heat without the smoke it would be a big improvement to the boat. Time to get stuck in. One way or another it was coming out of there, and we would find it a new home. Much of what follows will also hopefully be of use to anyone with similar issues or, indeed, fitting a new unit. Here’s what I did.