This page only covers ancillary items where we can give additional advice to readily available information.
Airtronic D2 and D4 pump.
Do not skimp on power cable size as doing so will cause frustrating intermittent low voltage failures.
Much thicker power supply cables are needed than you would expect from the amperage figures in the manual.
The reason for this is to reduce the voltage drop in the cables. Full details are on the Low voltage and wiring pages. For the D2 / D4 heaters which draw up to 10 amps during starting Eberspacher recommend 4mm2 wires for up to 2.5m individual wire length; ie 2.5m positive wire and 2.5m return wire. Increase the cable size to 6mm2 up to 4m, and 10mm2 or more for longer runs. Current rating for these cables is quoted by some sources as 4mm2 cable 32 amp, 6mm2 40 amp and 10mm2 55 amp. Older models and the Airtronic D5 take about 20 amps during starting and for these the cable sizes should be doubled. If you you are tempted to use some old cable with an unknown rating check it for size against those shown on our Wiring page.
The controller and other wiring carries less current so can be run in almost any normal cable thickness.
Battery supply cables.
Fuel pump mounting brackets.
Old style and the newer rubber fuel pump mounting brackets. The rubber version reduces noise transferring to the chassis.
Brackets front view.
Exhaust silencers and clamps.
We consider a silencer essential to reduce noise to neighbours. The noise reduction from the vehicle type silencer is fair, some users fit two to give a bigger reduction. They are not gas tight and must not be used in enclosed spaces. Check your pipe size before buying, 22 and 24mm often listed. Views of the non gastight seams and a silencer cut open are on the Silencer Autopsy page. Webasto versions have a drain hole in the casing. Vehicle type exhaust silencers are unsuitable for marine use. Better marine silencers are available from a dealer, they are gas tight and are much quieter. Use good quality clamps on exhausts and silencers to ensure a gas tight seal, two suitable types are shown. Jubilee type clamps do not tighten enough to compress the pipe. The cheaper U shaped clamps sold on ebay from Turkey, not shown, are thin metal and are totally unsuitable for exhausts.
Combustion air Inlet and Exhaust pipes.
Contact with the hot exhaust can cause painful burns or might start a fire. Also the fuel line may pass fairly close. We recently measured the pipe and it was about 105 deg C, close to the boiling point of water, much lower than expected. However under fault conditions it can get much hotter. Here it is spiral lagged using 50mm glass fibre tape. Insulating sleeves are also available. Try Ebay or Google "Exhaust lagging" for stockists.
Eberspacher Inlet / outlet pipe connections are in several sizes so check the manual for the correct size. Flexible exhaust pipe can make installation easier. The combustion air inlet pipe (right) does not have to be metal. Both pipes should be at least 200mm long. The combustion air must not be drawn from living areas. Some very old heaters need the inlet same length as exhaust. See below for clamps.
Combustion air Inlet Silencer.
The combustion air inlet is a lot quieter than the exhaust but an inlet silencer can make a reasonable noise improvement. Derek has one on his D2 but on my D1LCC I just have an exhaust silencer. Eberspacher also have a range of tubular inlet air silencers, check with dealers for details.
We bought a cheap air inlet silencer from Turkey on Ebay to evaluate but it was such poor quality we looked for an alternative. Both silencers have similar construction with a central tubular path that should allow the air to pass without obstruction. Foam encircling the tube absorbs some of the noise, unlike a filter the air does not pass through the foam cells. We want to do comparison listening tests and also to make a DIY silencer but they can be done in warmer weather.
Two combustion air inlet silencers. Webasto filter on the left fits 22mm tubing and came with a mounting clamp. (£13.96 inc postage webastomarine.co.uk)
Filter from Turkey right is poor quality, fits 25mm tubing, is about 125mm long overall and costs more. (£14.99 Ebay)
Webasto combustion air inlet filter. End parts unclipped to show construction. It can be installed in middle of pipe as well as at end. Construction quality of this silencer is very good. Air passage through it is 100% clear. Black silencing foam looks good quality.
Badly made filter from Turkey, foam part blocking the air path. We contacted the supplier saying we were reviewing it and were checking in case we had received a faulty unit. Their reply made it clear it was normal. "Well it is made of sponge. It is not air tight. Air will go through the sponge" We do not recommend this air filter.
Another view showing through air path is partially obstructed. Sucking and blowing through the tube is not a scientific test but as expected a higher air resistance than the Webasto. We estimate that the clear area in the tube is only about a third of the total area. Also the sponge looks cheap raising concerns as to how long it will last, if it breaks down pieces could enter the heater.
7 day timer with diagnostics.
Second hand Eberspacher heaters are often sold without pumps so used pumps are always in demand and are not cheap. Some used pumps may have been mounted under the chassis and the case can be corroded but this is generally not a problem as they are designed for external mounting. Eberspacher Fuel pumps come in 12v and 24v versions as well as several different supply rates. The Airtronic D2 and D4 use the same pump. Pumps contain a fuel filter and a non return valve. Pumps are adjusted during manufacture to deliver the correct amount of fuel for each model so Eberspacher say pumps from a different model are not interchangeable. However if the correct pump is not available you sometimes may be able to alter the pump spring tension to adjust it enough to match other models. This adjustment is limited so do not expect a 3.1-5 kw pump to adjust to match lower heat pump versions.
Do not buy Webasto pumps, more details on fuels page.
It is very important to use the correct fuel pipe and to pick up the fuel at the correct point to prevent a lot of fuel related problems. Our fuel pages have more information plus servicing advice.
Heating air hose and fittings.
Each Eberspacher air heater has a rating for maximum permitted heating air ducting length, exceeding this can cause overheating. Fittings such as bends, outlets etc can rapidly exceed this allowance. Each heater also has recommendations for the diameter of the ducting. Check length / number of fittings etc is within specification, detailed ducting instructions are in the Marine Heater Installation Guide - Airtronic D2 D4 D5, download from http://www.eberspacher.com. A far better installation guide if you can get hold of it is Marine catalogue - information, technology, tips 12/08, it has a picture of compass on the front page. We can only find one place to download it http://butlertechnik.com/download/Bj/Eberspacher_Marine_heater_Installation_Advice.pdf
Heat loss from hoses running through lockers can be considerable, reduce this by adding insulation round them. Items such as Screwfix loft insulation provide a neat solution. Ducting should have a 300 deg C rating, early on we bought some plastic hose advertised as for Eberpachers and it melted on test.
Another useful tip: Consider very carefully if the output(s) could be accidentally blocked, usually by bags or luggage. Sometimes this can destroy the ECU. If you cannot guarantee they will always be clear split the duct to feed multiple outlets so one is always clear, or fit protective cages.
Right angled outlet hoods can use up to half the duct length allowance. Use the straight hood and a gentler hose bend if space permits.
Right angled outlet hoods on a D4 are allowed. Right angled outlet hoods must not be fitted on a D4 plus as they cause excessive turbulence and case damage, it is ok to fit a straight hood immediately followed by a 90 degree elbow.
I have just noticed some ebay listings for this timer so have quickly added this item and a warning. Ebay is listing some timers November 2012: Eberspacher 7 day timer 24v, 8EU 007 628-13,22 1000,31 69 00, MAN 81.61990.0089 The front looks like the normal timer but the number reveals it is modified for a MAN truck which has a modified heater control system. No details are available of the modifications made to these non standard timer versions during manufacture. We cannot be sure but it is quite possible that they will not work with a normal Eberspacher heater, see main Buying advice page. For more details see Controllers page.
Temperature controller details are on the Controllers page.
Seriously consider one with diagnostics facilities like the 801, the 701 (with blue logo, not white) or EasyStart Select (only fits latest heaters).
Diagnostics really do help when you have problems and can often save hours of investigation or dealer charges.
Do not replace studs with stainless steel, they cause corrosion. Fit locking washers, not Nylock nuts, the nylon can melt.