Le Tonkinois Varnish

B & D Murkin

UK main importers for

Le Tonkinois varnish

Flexidisc sander

Dead Eberspacher heaters or parts, Donations

As a pensioner I have more or less gone as far as my wallet will allow on our website, but I can go quite a bit further with help from you guys. I provide this service completely free but if you feel it is worth a donation my Paypal account is eberspacher.info@gmail.com    Include your email address if you would like an acknowledgment.  All donations will be used to improve the website.

I love to get my hands on unwanted Eberspacher heaters to learn more about them or faulty heaters and components which I can take apart to photograph and reveal a few secrets. I still have a lot more to learn about the inner complexities of components such as fan motors, ECUs, burners and pumps. Dead heaters and components tell me a lot. Have a look at our Burner and Silencer autopsy pages and you will see what I mean - it clearly shows what has gone wrong - something I would not have seen with a good one. If you have heaters or parts, excluding used screens and gaskets, which are unwanted or heading for the scrapheap, please get in touch and I can sort something out. I would expect to cover the carriage.    

Thanks folks.

Eberspacher Diesel Heater Introduction

You may be wondering why free independent DIY help on Eberspacher and Espar heaters is included on a commercial varnish and sander website. During our Le Tonkinois Varnish and Flexidisc Sander demonstrations on boat shows we became aware that many Eberspacher owners lacked the information to service and repair their heaters. We love our Eberspacher heaters and this section of the website was originally added as a thank you to our existing customers but has expanded to become a unique and highly respected source of Eberspacher information.

Eberspacher diesel heaters are designed for use as night heaters in trucks but are also installed in boats, caravans and vans. Their main advantages over gas heaters are the significantly lower fuel cost and they can run from the engine diesel supply.

These web pages are not intended to replace dealers or service agents, just as Haynes car manuals do not replace garages, but to enable users to do some servicing and repairs on their own Eberspacher heaters. Our pages are primarily aimed at boat and caravan owners who are experiencing problems or wish to avoid future problems.

Diesel heaters are reasonably simple devices and are usually very reliable if regularly serviced. Many users are surprised there are so many reasons for heater problems, I try to cover all causes that I can think of, many are just theoretical. I now cover these problems in depth except for those caused by installation which should be done by professionals so the site contains a great deal of information and is still expanding as I learn more.

Hence finding the bit you need may take a little time.

The Site guide tab lists all pages with a brief description of contents and is helpful to find your way around.

Individual models are covered in the models pages.

The starting point for users experiencing Eberspacher heater problems are the fault finding and servicing pages.

New users should look at all of the current page, and the Eberspacher Models pages.

Eberspacher and Espar manuals details are on the Manuals page.

My contact details are given at the bottom of this page.

I, Roy,  am a retired professional electronics engineer.

I am not an Eberspacher professional, just an enthusiastic and very knowledgeable amateur.

I do this as a hobby, not a commercial business, so do not service, repair or sell Eberspacher heaters or spare parts.

Brother Derek used to specialise in the mechanical side but died recently so I am now covering everything.

Only Eberspacher diesel heaters are covered on our site. Petrol heater models are similar but petrol is more dangerous and need to be serviced by people who can safely work with petrol.

I know a lot about Eberspacher air heaters and am also steadily increasing my knowledge of Eberspacher water heaters.

Eberspacher D1LC Compact (D1LCC).

Eberspacher D2 Airtronic.

Eberspacher Airtronic heaters - How they work

Fuel is pumped in tiny measured amounts into the Eberspacher heater.

It is mixed with the combustion air and burnt in the combustion chamber, the hot gasses pass through the inside of the heat exchanger before reaching the exhaust.

Heating air is drawn into the front of the heater and is heated as it passes over the outside of the heat exchanger.

The heating and combustion air paths are completely separated.

Eberspacher Airtronic heaters adjust their heat output automatically between Boost, High, Medium, Low & Standby settings. Other models may have a different number of settings, the oldest have only full or half heat.

Although the pages are primarily based on Eberspacher D1LCC, D3LCC, and Airtronic D2 D4 D5 heaters most of the information applies to other models including Eberspacher water heaters.

For non current Eberspacher models look at the models pages, any model specific information will be given there.

I am in the process of adding specific pages for Eberspacher water heaters. It takes a considerable time for me to research and prepare the information so these pages may not be published for a long time. I will do my best to get the water heater information accurate but my practical knowledge on water models is limited as we do not use them, please feedback any additional information you have to improve the pages.

I am aware of Eberspacher Technical Bulletin 281, ‘Inland Waterways Boat Heating Findings’.

This document is about solving common problems on narrow boat Eberspacher water heater installations. It also applies to other boat installations.

Some of our information is available from various sources but a lot is not easy to find. Forum articles are notoriously difficult for the non expert because they include a lot of wrong or irrelevant advice. I have combined the most useful information from these sources together with a large amount of our own experience into a single reliable source. If you notice errors or have additional information let me know so I can improve the site.

I do not include most Eberspacher installation details, that is not the purpose of this site, I recommend installation is done by Eberspacher dealers. Installation and repairs should always be done to a very good standard, bad installations can be dangerous and might invalidate insurance.

If you need a dealer a list of Eberspacher main dealers is on www.eberspacher.com.

Eberspacher heaters were marketed under the Espar name in America and Canada.

Ardic heaters are also a part of the Eberspacher group of companies but we know nothing about them.

The complete stock of Ardic spares are now held by Espar Plymouth,.

I occasionally get asked if I also cover Webasto heaters, sorry I only know about Eberspacher heaters but they work in a broadly similar way so quite a lot of the general Eberspacher information will also apply to Webasto heaters.    www.sportsmobileforum.com/forums/f24/hal-the-van-3004-33.html is recommended by Maurice Cotton, it contains a lot of Webasto information.

If you are going to service a model I have not pictured here please read my request for photos below.

WARNING Some sellers on Ebay are listing used non standard Eberspacher truck heaters, some will not work as standard heaters when taken out of the truck, see our Buying advice pages for more information and advice to avoid some very expensive mistakes.


You use any information and advice we give entirely at your own risk.

If you do not accept this do not use this site, go to an Eberspacher dealer.

We have tried to make it as accurate as we can but accept no liability for errors or problems caused by following our pages.

Some of the information is only suitable for people with a good aptitude for mechanical and electrical repairs. Any DIY involves some risk of accidents and you must decide if you are capable and can do it safely before carrying out any work.

You should also ensure your DIY is done to a professional standard in order to avoid creating potential hazards and insurance invalidation. Boat installations must strictly comply with Marine regulations.

Heating air path

Heating air inlet

Heating air impeller

Electronic control unit

Heat exchanger outer

Heated air outlet

Combustion air path

Combustion air inlet

Combustion air impeller

Glow pin and screen

Combustion chamber

Heat exchanger inner


Bottom centre  Fuel inlet from pump.

Eberspacher Hydronic water heaters - How they work

Hot water path

Water inlet

Heat exchanger outer

Heated water outlet

Combustion air path

Combustion air inlet

Combustion air impeller

Glow pin and screen

Combustion chamber

Heat exchanger inner


Top centre Fuel inlet from pump.

Fuel is pumped in tiny measured amounts into the Eberspacher.

It is mixed with the combustion air and burnt in the combustion chamber, the hot gasses pass through the inside of the heat exchanger before reaching the exhaust.

Water flows through the heater and is heated as it passes over the outside of the heat exchanger.

The water and fuel pumps are external to the heater on some heaters and are not shown in this model.

Heater adjusts its heat output automatically to regulate water temperature.

Model names

Eberspacher model naming is confusing so a brief explanation of the models may help.

Older models had a naming convention, newer models do not follow this system, typical of Eberspacher!

First Letter - D diesel, B petrol.  

Number generally represents heat output, higher number higher output

Letter - L air,  W water.  Older models only, newer models do not use this convention and use L for Large!

Any letters following identify the model, eg D1L,  D1LC,  D1LCC.

Air Heater models

They were manufactured in the order   D1L,  D1LC,  D1LCC, with Airtronic D2 being the current model.

Similarly for higher heat models            D3L,  D3LC,  D3LCC, with Airtronic D4 being the current model.

                                                                (Airtronic D3 is not sold in UK)

                                                                D4L,   D5L,    D5LC,   with Airtronic D5 being the current model.


Water heater models

Oldest models             D4W (not sold in UK), D5W, D7W, D9W, D10W.

Hydronic OEM             D3WZ, D5WZ, possibly D4WZ,  (OEM specific heaters with no water pump)

Hydronic current          D4WS (24v), D4WSC (12v), D5WS (24v), D5WSC (12v)

Hydronic II                   D4S, D5S, D5SC   (Not currently being sold in UK, they are on the continent)

Hydronic M I                D10W

Hydronic M II (2013)   M8, M10, M12,

Hydronic L I                 L16, L24, L30, L35

Hydronic L II                LII16, LII24, LII30, LII35

Stating the obvious, when identifying models always look at the label, especially before contacting us.

Most labels show 3 consecutive years, eg 01 02 03.  This was originally a requirement of German approval. The Eberspacher installer would mark the label with the year the heater was commissioned but I have never seen any label marked. All you can tell is the heater was made in 2001, possibly earlier, and probably first installed in 2001, 2002 or 2003.

Manuals and servicing information

Download links for manuals is on the Manuals page.

Servicing information for many models is in the servicing pages

Servicing and repairing other Eberspacher heater models should be similar enough to enable them to be done without instructions.

Please take plenty of photos so I can add more models to our servicing pages to help other users.

Contact us

If your fault is not covered in our fault pages I give advice but my other interests and the number of queries means at peak times I occasionally have to limit the time spent for each query. It is in your own interest to use our webpages before contacting me, otherwise you may run out of time for advice.

I have a questionnaire in Microsoft Word document format that covers the type of information I would generally like for many of the problem queries, it will not apply to all problems, click here to download a copy.

I deal with queries as and when convenient, I do it as an unpaid hobby and other things can be a higher priority. If you get no reply after a couple of days your email or my reply has probably been lost in the system so contact me again.

I have no crystal ball, you have to be my eyes and ears, the more info you give the more chance of getting a good result. Queries that give an inaccurate or ambiguous model type, especially with water heaters, means wasted time either asking for the corrected model information or by giving information for the wrong model. Inevitably those are the first queries I stop dealing with at peak times.

My practical knowledge of water heaters is slightly limited as we don’t use them, it is improving as I deal with more queries but there may be some gaps.

Derek  became increasingly annoyed that after spending a great deal of time preparing carefully worded replies some people did not have the courtesy to say thank you or feed back details of whether our diagnosis cured the fault. I am noticing the same problem.

Feedback on our Eberspacher advice pages has been very positive, keep it coming.

I would appreciate an email, contact details below, if you found these articles useful. It helps me to gauge how much interest there is and keeps me motivated.

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