Heater setup

[treeman]

I have been trying to work out how the Eberspacher Airtronic heater works in my recently acquired Renault Master. The van was converted by Classical Designs in '91 but the heater has been added much more recently. It runs independently of any controls on the Zig CF8 control on board. My problem is it only works on heater when the engine is running - which is not very desirable as I'm sure the idea is to have a heater that works when parked up. The control unit is the very basic Standard Controller which which works all the time. If I switch the blower on (blue light) it runs fine engine on or off. If I switch the heater on (red light) it only fi9res up the heater if engine is running.

After much searching and forum browsing I am at a loss. Is it something to do with the diesel feed into the Airtronic maybe?

Are these a major drain on the batteries - I ask as I also have a battery issue?

 

[pappajohn]

not had anything to do with eberspacher but i would say the ignition circuit is wired to the wrong circuit.....possible the fridge 12v circuit which should only work with the engine running.

the 12v fan for blown air will hammer the batteries as it will draw around 10amps.

sorry cant be more specific but as i said...had nowt to do with them :thumb:

 

[treeman]

That's what I thought it might be too, but the fridge is on it's own separate circuit with it's own toggle switch next the the ZIG board and switching that on or of does nothing to the heater.

As the controller and the fan work all the time I'm thinking they both must be connected direct to battery so checked voltages and 12.6 to 12.8 and yet still not firing up the heater.

 

[aba]

could be that you are low on fuel or the heater has a separate fuel tank fitted somewhere.
although this could be of help.
http://www.eberspacher.com/downloads/technical-documents/d9283017.pdf

http://www.eberspacher.com/support-and-downloads/technical-documents.html

 

[Taran_Las]

I believe these heaters are prone to cutting out when the battery is low. Do you have manuals for the unit?

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[treeman]

Thanks for the links, I had downloaded the pdf manuals and other literature already and read through them. I recollected a low battery and low fuel cut-out so intentionally went and filled up with fuel and recharged the batteries but still no joy. I remember reading the undervoltage cutout was about 10.5 volts under which heater would cut out. I'm assuming that's what undervoltage cut out means.

On the subject of a second fuel tank I think this unlikely as the heater works fine as long as engine running.

 

[treeman]

Looked at wiring diagram but can't see anything obvious - is it possible that there is a separate feed to the heater and the fuel pump (dosing pump?) - and could one be permanent 12v and the other be off the ignition 12v?

 

[Glynn]

When you 1st switch it on what happens ?, they usually start with a slow ticking noise, this is it pumping the fuel up.Then the fan will start and then it will fire and you will hear a noise like a quite jet engine. This noise subsides as it heats up. It all takes a few minutes.

 

[treeman]

With engine off, after I switch heater on there is short delay then I hear a click as if the heater is about to start but nothing happens after that.

With engine on, I switch on heater and I think there is a click (can't hear much above engine noise - 25 year old van!) and the fan starts after another gap then heat starts to pump out.

 

[Reallyretired]

Probably not much help but I have an auxiliary diesel heater on my van, which is a standard Mercedes fitment. This only works with the engine running because of the high battery drain.

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[Johno]

Hi Treeman

The Eberspacher heaters are very voltage sensitive and draw a heavy current during the start up sequence, if your leisure battery is a bit tired this will cause the voltage to drop and the Eberspacher to cut out.:Sad:
You can try starting the heater with the engine running until the start up stage has completed and the heater is blowing warm then turn off the engine and run on battery,there is still a low drain on the battery at this stage and if your leisure battery is really poorly the voltage will still drop to cut out level after a short time usually around 11 volts.
The upside of these heaters is that they can be used while on the road keeping the van interior toasty on those cold winter trips which the engine heating never seems to be capable of doing:thumb:
Eberspachers do need servicing occaisionally and if yours is a few years old this could also be another reason for malfunction.
Hope this helps.

Cheers John.

 

[treeman]

Thanks John, I have tried what you say (starting heater with engine on then turn engine off) but the heater switches itself off very soon after the ignition is switched off. I checked the battery and still well over 12v output.

 

[aba]

it must have some of its wiring connected via the ignition switch somewhere.
it could be the dosing pump that is powered via the ignition although i thought that the wiring loom for the heater was a complete thing and separate from everything else.
i have removed a few of these but never re-fitted one.

personally i would look for the loom from the heater under the bonnet and check to see if any of it has been wired via the ignition and change it to the leisure battery that way it should work all the time.

 

[Terry]

It sounds to me like it has been wired up wrongly If your van has a rely to the heater wire this to the L/B so that it charges that while the engine is running and wire the heater straight to the L/B -It should use no power when turned off and you should get at least 24 hrs running if your l/b is OK :thumbepending on the size of your battery I would expect (if in good cond) it to run for around 3 days before flattening it.If the L/B is no good that could be the cause of your problem as they do not like anything dragging power down.Have they wired any lights or anything on the same circuit ?if so remove them or rewire the heater to it's own dedicated supply
terry

 

[treeman]

I agree that the wiring maybe amiss. Although the van was converted professionally in '91, I think since then a few "additions and alterations" may have occurred and the addition of the heater is one of them. I'm wondering if the heater caused battery problems and caused things to be re-wired as when I checked the batteries they are wired parallel together and both appear to be normal car batteries - even though the original paperwork and wiring diagram from the conversion shows 2 batteries on separate circuits. The pic below shows the 2 batteries as they are now.

Not much info was available from the previous owner, apart from he said he had added a new battery recently.

All that wiring around the batteries is a tad complex for me - I guess it is all to do with dual-circuit etc wired up to ZIG CF8?

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[aba]

is there not another battery anywhere else on the van????? under a seat maybe.
or maybe thats the problem.
the leisure battery where ever it is could be flat and that would cause the symptoms you are describing. you need to find either where the leisure battery is or should be.

 

[treeman]

I had wondered myself if there may be another battery so with the ignition off I monitored the voltage of the 2 batteries in the photo and on switching on the ZIG 12v switch and turning on the lights then there was a noticeable drop in voltage, then a rise in volts when I switched all lights off so I presumed from that it was these 2 batteries used as L/B - although also used to start van!

Having said that I will check out to see if I can find another battery. Not so easy as van is parked away from house but I will go now and check.

Thanks for all the help so far.

 

[icantremember]

I agree that the wiring maybe amiss. Although the van was converted professionally in '91, I think since then a few "additions and alterations" may have occurred and the addition of the heater is one of them. I'm wondering if the heater caused battery problems and caused things to be re-wired as when I checked the batteries they are wired parallel together and both appear to be normal car batteries - even though the original paperwork and wiring diagram from the conversion shows 2 batteries on separate circuits. The pic below shows the 2 batteries as they are now.

Not much info was available from the previous owner, apart from he said he had [HI]added a new battery recently[/HI].

All that wiring around the batteries is a tad complex for me - I guess it is all to do with dual-circuit etc wired up to ZIG CF8?

I can't help with your heater problems except to confirm most of the previous suggestions.

However, what I would say is that neither battery looks very recent and would be worth checking any dates on them.
Other than that, you say the batteries are wired together in parallel...if this is the case then I'm pretty sure they would be more effecient if they were identical in capacity and age. A small capacity battery or an old one will drag the better one down in peformance.

Brian

 

[pappajohn]

is there not another battery anywhere else on the van????? under a seat maybe.
or maybe thats the problem.
the leisure battery where ever it is could be flat and that would cause the symptoms you are describing. you need to find either where the leisure battery is or should be.

one way to be sure......remove the earth clamps from BOTH batteries and see if you still have habitation power.

no power, chances are no battery, unless its completely dead.

you may need a radio code before disconnecting.

 

[aba]

just another thought what position is the battery switch on the zig in as this may control which battery the internals work on.
if it is in the off position or touring it may use the engine battery and this should only be in this position when travelling.
when parked or on hookup it should be in the on position or on site and should power from the leisure battery.

i say the on and off positions for reference as on the unit it may be either a picture or writing.

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[Johno]

Hi Treeman
While reading all these threads with interest another thought came to mind if you connect your multimeter to the batteries with the engine running you should hopefully get a reading of around 14 volts, start and run the heater and with any luck the volts won't fluctuate to much, turn off the engine and keep an eye on the voltage readings for the short time the heater is running only on battery power, as I mentioned before if the volts drop rapidly it points to battery prob's. :Sad:
Using this method enables the battery voltage to be monitored while things are actually happening and the battery is under load, readings after events can sometimes be misleading as the volts under no load can often recuperate quickly making the battery appear better than it actually is.
I guess we 'll all keep putting our minds to this problem and come up with an answer eventually.

Cheers John.

 

[treeman]

Hi John, I like your idea, will give it a go tomorrow. There is no substitute for real-time measurement.

Also I have been told there is more to a battery than just a voltmeter can deduce so I might take them to a battery centre for a thorough test separately. I don't see the point of 2 car batteries in parallel anyway, I must get a L/B and wire separately if I can work out which wires go where!

I'll have a go at Pappajohn and aba's ideas too.

Thanks for all the help so far.

 

[Craig Rogers]

just another thought what position is the battery switch on the zig in as this may control which battery the internals work on.
if it is in the off position or touring it may use the engine battery and this should only be in this position when travelling.
when parked or on hookup it should be in the on position or on site and should power from the leisure battery.

i say the on and off positions for reference as on the unit it may be either a picture or writing.

I agree with this. If there is no Hab power then the heater will not work. Even though the heater isn't controlled via the zig, the zig will send power to the heater.

If I turn off my control panel, the heater will cut out.

 

[treeman]

Update....... after many many days.......

Having got my MH back to my house I read again all the posts and gone though many tests and finally got some answers.

Both batteries where connected in parallel under the bonnet which was bad, one was very poor in power and on it's own would not start the MH engine so was dragging the other battery down. The poor battery was meant to be the LB so I'm wondering if the previous owner connected them together to get some habitation power. Anyway I removed the cables connecting both batteries together and borrowed a used LB.

The other reason I found the heater didn't start the the massive power consumption on start up. The voltage on the newly installed (used) LB is not quit enough to start the heater but will run it fine once going, so I run engine and start heater then turn off engine and heater continues fine.

Heat at last!!!!

So reasons were:
1. knackered / incorrect LB (although 12.6v on meter, this plummeted when load applied).
2. Batteries wired in parallel (poor one impaired good one).
3. Lack of personal knowledge on MH electrics!

Thanks for all the help and tips, many of your points were spot on and pointed to the cause - thanks.....