Moonraker 2
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Just had a reply from another recommendation who said, No they don't fit heaters. Going to give up now.
Diesel Heater
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Sharpie
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Everything you might need to know about the care and maintenance of diesel heaters can be found at https://www.youtube.com/user/johnmck1147/videos
These are the Chinese ones that are a copy of the Eberspachers and Webastos. They have identical mountings so are a direct replacement typically for under £100 for the complete system. By most accounts reliable if used correctly. Basically you must run them flat-out periodically to burn off the internal soot buildup that occurs when they are ticking over at low outputs. The same applies to the German ones. There are only two moving parts, the fan/brushless motor, and the fuel pump. Not a lot to go wrong.
If your existing expensive German heater is not working properly, it may be much easier and far cheaper just to replace it with a new Chinese one rather than trying to diagnose the fault correctly, buy expensive spare parts, or even pay a specialist who knows what they are doing (not just a parts swapper) to fix it. It isn't cost effective to pay someone to do this.
Be aware that any diesel heater may perform poorly at high altitudes, they run rich and soot up, due to lack of oxygen, which can be a problem at e.g. ski resorts if used for long periods before descending and clearing them with a prolonged full-blast burn. The gas fired Truma seems unaffected, but sourcing and storing enough suitable LPG for an extended stay can be problematic. You need propane. Not butane, or a mix.
The Truma Combi diesel version uses an Eberspacher burner inside, and is a complete nightmare to service if you can find anyone who understands it, unreliable at altitude, and of course extremely expensive.
Continental autogas is problematic, usually a propane/butane mix even in winter. The propane is fine, but at low temperatures the butane content does not vaporise, leaving you with maybe half a tank full of useless liquid butane. I've experienced this after filling up abroad, then trying to use the gas in winter here. UK autogas is, I'm assured, 100% propane so has never been a problem.
Currently planning how to fit one underneath my Globecar and plumb it into the hot air ducting from the gas fired Truma combi. which could be quite complicated.
I could easily fit it internally, but that would take up precious space. Since I have a 125 litre diesel tank it makes sense to think about this, and reserve the gas for just cooking, heating water for showers, and running the fridge, given the now reduced availability of autogas in the UK, particularly Scotland, since Shell have removed most of their autogas points and talk of replacing them with electric charging points. Not very useful to me.
Autogas makes sense at a fraction of the price of e.g. Calor cylinders, diesel heating probably costs twice as much as autogas, but I can get it anywhere. So Gaslow refillable (already paid for itself many times over) plus a diesel heater makes sense to me, and I enjoy planning a project.
These are the Chinese ones that are a copy of the Eberspachers and Webastos. They have identical mountings so are a direct replacement typically for under £100 for the complete system. By most accounts reliable if used correctly. Basically you must run them flat-out periodically to burn off the internal soot buildup that occurs when they are ticking over at low outputs. The same applies to the German ones. There are only two moving parts, the fan/brushless motor, and the fuel pump. Not a lot to go wrong.
If your existing expensive German heater is not working properly, it may be much easier and far cheaper just to replace it with a new Chinese one rather than trying to diagnose the fault correctly, buy expensive spare parts, or even pay a specialist who knows what they are doing (not just a parts swapper) to fix it. It isn't cost effective to pay someone to do this.
Be aware that any diesel heater may perform poorly at high altitudes, they run rich and soot up, due to lack of oxygen, which can be a problem at e.g. ski resorts if used for long periods before descending and clearing them with a prolonged full-blast burn. The gas fired Truma seems unaffected, but sourcing and storing enough suitable LPG for an extended stay can be problematic. You need propane. Not butane, or a mix.
The Truma Combi diesel version uses an Eberspacher burner inside, and is a complete nightmare to service if you can find anyone who understands it, unreliable at altitude, and of course extremely expensive.
Continental autogas is problematic, usually a propane/butane mix even in winter. The propane is fine, but at low temperatures the butane content does not vaporise, leaving you with maybe half a tank full of useless liquid butane. I've experienced this after filling up abroad, then trying to use the gas in winter here. UK autogas is, I'm assured, 100% propane so has never been a problem.
Currently planning how to fit one underneath my Globecar and plumb it into the hot air ducting from the gas fired Truma combi. which could be quite complicated.
I could easily fit it internally, but that would take up precious space. Since I have a 125 litre diesel tank it makes sense to think about this, and reserve the gas for just cooking, heating water for showers, and running the fridge, given the now reduced availability of autogas in the UK, particularly Scotland, since Shell have removed most of their autogas points and talk of replacing them with electric charging points. Not very useful to me.
Autogas makes sense at a fraction of the price of e.g. Calor cylinders, diesel heating probably costs twice as much as autogas, but I can get it anywhere. So Gaslow refillable (already paid for itself many times over) plus a diesel heater makes sense to me, and I enjoy planning a project.
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Nabsim
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I was looking at some data sheets on the Eberspacher site earlier in the week and they state that once fitted you don’t need to touch them. All it says if not used then you should run it once a month. I know mine hasn’t been touched in the 22 months I have had my van and all seems good.
What is the maintenance they need and when?
What is the maintenance they need and when?
Caz
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The Eberspacher on my Autosleeper failed, cost hundreds to get it repaired, luckily the insurance paid a good whack towards it. I had to take it to their nearest specialist repairer, 35 miles away. It took him hours of work and two goes at it to get it going properly again. He said it had never been serviced since new, 13 years old, and that was why it had packed up.
FULL TIMER
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The only part that might need changing on D2 / D4 models as long as filters don't get clogged up is what they call a plug strainer, this is an easy job to do as long as access to the top of the heater is ok, the glow pin has to be removed and the plug strainer is located in the bottom of the hole simply hook it out and replace with a new one, you'll know if it needs changing as the heater will smoke quite badly on start up or even fail to establish a flame and then shut down. the most problems I have with the ambulances is overheating mainly due to staff blocking up either one of the warm air inlet/ outlets with a bag or something. Also worth checking the air inlet on the heater for a build up of fluff / hair etc as this could also cause the heater to overheat .
Sharpie
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From what I gather, from the youtube chap I referenced, there is no routine maintenance needed. However you do need to run them hard periodically to keep the soot buildup at bay.
The burner relies on a glow plug to start it, as well as a tiny fine wire mesh screen beneath the glow plug, fuel is delivered a drop at a time, hence the ticking from the pump, upon which the diesel is vaporised. If the wire mesh screen gets clogged it wont work.
It seems that that the glow plug and screen are easily accessed on the Eberspacher design, should they fail, which seems rare when used correctly.
The Webasto design is not so easy, the whole thing has to come out and be taken apart to access these parts.
Start up and shut down is controlled by electrickery, and must be completed under full control. If e.g. your battery runs flat and whatever system you have just cuts the power, or trips the low voltage cutoff of the heater controller, then there is the possibility that the burner and even exhaust pipe, if incorrectly routed, could fill with diesel with various dire consequences if the shut-down sequence from the controller is interrupted.
Shut down takes several minutes to complete properly. Start up, running and shut down all require steady strong electrical power to be maintained. You can't just turn these things on and off like an LPG powered heater that just uses a spark plug for ignition, minimal power.
Start up requires a lot of current to the glow plug, for a minute or two. If your batteries are low or weak they may not even be able to complete the startup sequence. Once running the only power draw is from the fan, which is still significant. You need a good electrical system to run one of these.
There is also a critical gasket that separates the burn chamber from the hot air that actually circulates inside the van, and should be isolated from the combustion products. If that fails then there is the possibility of CO getting into the hot air.
So these are not actually simple things, and need to be installed with care and thought, particularly the exhaust pipe routing and fresh air inlet pipe to the burner, (external to the van), then the hot air inlet and outlets inside the van. Noisy too, outside the van, lots of discussion about how to quieten this. The burner itself is not much different than say an old Primus stove with a roarer burner, same principle, diesel/paraffin/kerosene is vaporised on the tiny wire mesh piece then combusted by the forced air that the fan supplies.
The controller is supposed to regulate the airflow to the burner according to the power demanded, but as I said they don't compensate for altitude, temperature nor for air intake and exhaust restrictions, it's amazing how well they usually work, but in particular running one at say Zermatt, for a week or two continuously, will probably be problematic. A fellow camper relying on his Truma Combi Diesel found this out, cost him over £4000 for a complete replacement, it was so sooted up it couldn't be repaired, allegedly. plus fitting.
Putting one into a boat introduces a whole extra set of problems.
A professional e.g. Eberspacher installation on e.g a truck when manufactured should have addressed these concerns and should have been correctly maintained or at least regularly checked by the fleet services. And run within its design regime.
The Eberspachers have a tiny fuel filter incorporated into the pump. If your diesel is not winter grade, or maybe poor quality it may gel up or just drop wax crystals when cold. Or even in summer, just contaminated, maybe by a bit of the gunge that grows on diesel (sailors know about this). Then of course they stop working. So a decent inspectable filter that can be easily drained of water and other contaminants is a good idea.
A DIY job with a £99 ebay heater done without much understanding could easily go wrong, I've seen some horrific incompetent installs on youtube.
Not the fault of the heater itself, as I said they seem to be generally well made straight copies of the originals, and the controllers are if anything rather more sophisticated, depending which one you choose.
The burner relies on a glow plug to start it, as well as a tiny fine wire mesh screen beneath the glow plug, fuel is delivered a drop at a time, hence the ticking from the pump, upon which the diesel is vaporised. If the wire mesh screen gets clogged it wont work.
It seems that that the glow plug and screen are easily accessed on the Eberspacher design, should they fail, which seems rare when used correctly.
The Webasto design is not so easy, the whole thing has to come out and be taken apart to access these parts.
Start up and shut down is controlled by electrickery, and must be completed under full control. If e.g. your battery runs flat and whatever system you have just cuts the power, or trips the low voltage cutoff of the heater controller, then there is the possibility that the burner and even exhaust pipe, if incorrectly routed, could fill with diesel with various dire consequences if the shut-down sequence from the controller is interrupted.
Shut down takes several minutes to complete properly. Start up, running and shut down all require steady strong electrical power to be maintained. You can't just turn these things on and off like an LPG powered heater that just uses a spark plug for ignition, minimal power.
Start up requires a lot of current to the glow plug, for a minute or two. If your batteries are low or weak they may not even be able to complete the startup sequence. Once running the only power draw is from the fan, which is still significant. You need a good electrical system to run one of these.
There is also a critical gasket that separates the burn chamber from the hot air that actually circulates inside the van, and should be isolated from the combustion products. If that fails then there is the possibility of CO getting into the hot air.
So these are not actually simple things, and need to be installed with care and thought, particularly the exhaust pipe routing and fresh air inlet pipe to the burner, (external to the van), then the hot air inlet and outlets inside the van. Noisy too, outside the van, lots of discussion about how to quieten this. The burner itself is not much different than say an old Primus stove with a roarer burner, same principle, diesel/paraffin/kerosene is vaporised on the tiny wire mesh piece then combusted by the forced air that the fan supplies.
The controller is supposed to regulate the airflow to the burner according to the power demanded, but as I said they don't compensate for altitude, temperature nor for air intake and exhaust restrictions, it's amazing how well they usually work, but in particular running one at say Zermatt, for a week or two continuously, will probably be problematic. A fellow camper relying on his Truma Combi Diesel found this out, cost him over £4000 for a complete replacement, it was so sooted up it couldn't be repaired, allegedly. plus fitting.
Putting one into a boat introduces a whole extra set of problems.
A professional e.g. Eberspacher installation on e.g a truck when manufactured should have addressed these concerns and should have been correctly maintained or at least regularly checked by the fleet services. And run within its design regime.
The Eberspachers have a tiny fuel filter incorporated into the pump. If your diesel is not winter grade, or maybe poor quality it may gel up or just drop wax crystals when cold. Or even in summer, just contaminated, maybe by a bit of the gunge that grows on diesel (sailors know about this). Then of course they stop working. So a decent inspectable filter that can be easily drained of water and other contaminants is a good idea.
A DIY job with a £99 ebay heater done without much understanding could easily go wrong, I've seen some horrific incompetent installs on youtube.
Not the fault of the heater itself, as I said they seem to be generally well made straight copies of the originals, and the controllers are if anything rather more sophisticated, depending which one you choose.
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Nabsim
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@FULL TIMER my D4 is mounted under the fixed French bed with pretty good access so if I need to get to the plug strainer it shouldn’t be too bad thanks. I can either access from above by lifting the bed or my preferred way would be through the external locker standing outside, what’s the betting it will either be throwing it down or a foot of snow if it’s needed though lol
Fazerloz
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How can this possibly happen in a correctly installed unit as loss of power immediately stops the pulse metering pump and stops supply of fuel to the burner unit. The pump doesn't and can't carry on running down and filling the heater with fuel.
Sharpie
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If the power to the system is suddenly cut, pressure will remain in the fuel line between the pump and the burner. As soon as the fan stops the flame goes out. The residual fuel then enters the burner. That's why the shut down sequence is required, during it the fuel pump is stopped, the residual fuel burned off safely and the fan then continues to run for a while to cool the unit.
Otherwise you have a red hot burner, with a quantity of unburned fuel inside, which then heat-soaks into the rest of the unit, maybe damaging the critical gasket I mentioned that is the only thing separating the burner and the hot air that circulates inside the van Maybe even cooking the electronics of the controller inside the unit.
A poor installation makes this worse. The pump should be as close as possible to the burner with the shortest possible run of the correct pressure tube which is inelastic to minimise the amount of fuel between pump and burner.
Likewise if the startup sequence fails, perhaps the glowplug doesn't get hot enough, maybe battery current insufficient or the wiring of insufficient gauge to handle the heavy startup current properly, or the wire gauze is in poor condition, the unburned fuel enters the burner and even the exhaust pipe, where it can even pool inside if the exhaust run is incorrect. Repeated failed attempts to start the thing up just add more fuel and make matters worse. If you do eventually succeed in starting up you can expect a smoky smelly exhaust until this has cleared, as well as sooting up the burner
Otherwise you have a red hot burner, with a quantity of unburned fuel inside, which then heat-soaks into the rest of the unit, maybe damaging the critical gasket I mentioned that is the only thing separating the burner and the hot air that circulates inside the van Maybe even cooking the electronics of the controller inside the unit.
A poor installation makes this worse. The pump should be as close as possible to the burner with the shortest possible run of the correct pressure tube which is inelastic to minimise the amount of fuel between pump and burner.
Likewise if the startup sequence fails, perhaps the glowplug doesn't get hot enough, maybe battery current insufficient or the wiring of insufficient gauge to handle the heavy startup current properly, or the wire gauze is in poor condition, the unburned fuel enters the burner and even the exhaust pipe, where it can even pool inside if the exhaust run is incorrect. Repeated failed attempts to start the thing up just add more fuel and make matters worse. If you do eventually succeed in starting up you can expect a smoky smelly exhaust until this has cleared, as well as sooting up the burner
Deleted member 5816
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As far as I am aware there is no pressure in the fuel pipe from pump to heater the pump is a solenoid pump and is always fitted below the heater when stopped there is no pulse so fuel stopped no pressure, admitted the shutdown is not completed which is mainly to cool the hot heater down.
Sharpie
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Further: if planning to mount the heater under the floor of the van, as I am, the fuel line, pump and heater are all level with or below the diesel tank. If anything fails in this, there is the potential for the diesel to syphon through and trickle onto the ground, or even enter the heater. That would not make me popular. Potentially 125 litres of diesel contamination to the campsite soil to be rectified. Or just £150 of diesel spilled onto the road whilst driving along.
I doubt that my insurers would be sympathetic.
There are strict regulations about the fuel routing of vehicles to make sure this never happens. But once you bypass all this, maybe even just running a length of vinyl tube from B&Q from the drop tube that you have inserted into your exquisitely designed fuel tank after drilling a hole in the top, perhaps rigged up with cable ties, barbed connectors, bits of dubious rubber hose and the odd jubilee clip, exposed to damage by anything thrown up from the road, all bets are off.
Ideally there should be an isolation valve between the drop tube from the tank and the rest of the system, further complexity and you'd have to be in the habit of using it.
Hey-ho, you can see all these sorts of lash ups proudly presented on youtube by clueless amateurs.
My setup will probably instead use a steel jerrycan that just fits in the gas locker alongside the Gaslow cylinder as the supply. Filled up by either syphoning from the vehicle tank, or filling up at a service station.
I doubt that my insurers would be sympathetic.
There are strict regulations about the fuel routing of vehicles to make sure this never happens. But once you bypass all this, maybe even just running a length of vinyl tube from B&Q from the drop tube that you have inserted into your exquisitely designed fuel tank after drilling a hole in the top, perhaps rigged up with cable ties, barbed connectors, bits of dubious rubber hose and the odd jubilee clip, exposed to damage by anything thrown up from the road, all bets are off.
Ideally there should be an isolation valve between the drop tube from the tank and the rest of the system, further complexity and you'd have to be in the habit of using it.
Hey-ho, you can see all these sorts of lash ups proudly presented on youtube by clueless amateurs.
My setup will probably instead use a steel jerrycan that just fits in the gas locker alongside the Gaslow cylinder as the supply. Filled up by either syphoning from the vehicle tank, or filling up at a service station.
Sharpie
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Actually there is some pressure between pump and burner. That's why they need the proper rigid tube in the shortest run. As the solenoid pump moves back bubbles form in the diesel under vacuum. From air, water but mostly volatile hydrocarbons present in the fuel. As it moves forward this gets compressed again but not fully re-absorbed. Hence the need for the pump to be mounted near vertical so that the burner remains fed with fuel, and the gas bubbles can rise up and flow through, rather than causing a vapour lock.
The entrained gas bubbles keep the fuel squirting into the burner after the pump has been stopped. Maybe not a lot, but fuel does continue to flow after the pump stops.
The controller knows about this and the startup sequence includes pump priming steps to try to minimise this. When correctly shut down the line from the pump to the burner should be devoid of most fuel, so start up requires it to be re filled.
If you run out of fuel then have to re purge the system it can be slow or just impossible if the fuel run or pump installation is incorrect.
The entrained gas bubbles keep the fuel squirting into the burner after the pump has been stopped. Maybe not a lot, but fuel does continue to flow after the pump stops.
The controller knows about this and the startup sequence includes pump priming steps to try to minimise this. When correctly shut down the line from the pump to the burner should be devoid of most fuel, so start up requires it to be re filled.
If you run out of fuel then have to re purge the system it can be slow or just impossible if the fuel run or pump installation is incorrect.
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Deleted member 5816
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,My heater is mounted under the van but between the van floor and splash shields so not open to road dirt the heater ,pipe work and heater are above the fuel tanAs per manufactures instructions the pump is mounted between 15 and 35 degrees. The heater gets plenty of use as we use the van all year round it’s 13 years old stripping last year the heater looked like new they are designed for truck cabs where the running hours are far in excess of most motor caravan users.
All the heaters I have seen or heard about that are suffering low voltage seem to have been wired to the leisure battery and quite a few with undersized supply cable.
Alf
All the heaters I have seen or heard about that are suffering low voltage seem to have been wired to the leisure battery and quite a few with undersized supply cable.
Alf
Nabsim
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I have a Hydronic that is mounted below the passenger headlight in the engine compartment and a D4 mounted at inner floor level under the bed. The D4 was professionally fitted by a previous owner (I have retired receipts) but pump sounds like it is in the engine compartment maybe 5 metres away.
The D4 has never failed due to low voltage but will fail if diesel level gets too low.
The D4 has never failed due to low voltage but will fail if diesel level gets too low.
Fazerloz
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Fazerloz
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Rigid tube is used purely to ensure correct dosage.
Cavitation bubbles only appear in positive displacement pumps on the suction side and as they enter the delivery side they disappear. So no bubbles should be seen in the delivery pipe. Unless the pump is pulling in air from somewhere and if so there is a fault either in the installation or the pump.
As the pumps can be mounted up to 6m away according to the installation manuals from the burner how do you get as you claim.
"When correctly shut down the line from the pump to the burner should be devoid of most fuel, so start up requires it to be re filled"
Is all your knowledge of these heaters gleamed from youtube?
Deleted member 5816
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The Eberspacher instruction say upto 10 metre maximum for pump distance from heater the only fixed distance is the vacuum draw to the pump. The standpipe in the tank in mine must be 50mm or so from the bottom I have had the heater fail once parked on uneven ground with a front to back and side to side slope.
Alf
Alf
Nabsim
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I don’t know what distance mine is set for but it’s approximately an eighth of a tank when it runs dry for the heater. That must have been when reasonably level as it’s done it twice and I know last time I was only a few degrees off level (unusually). I would expect the installer followed recommended specs but who can be certain without checking