Eberspacher thermostat question

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mixmaster

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Hello,

I have an Eberspacher 5DL which runs just fine when it comes to generating lots of heat. The problem we have and have always had is that it seems to either generate too much heat or none at all. The controller (which looks like this one: https://www.pfjones.co.uk/modulator-switch-30100154.html) doesn't control the temperature very well. The unit is either on and when I move the dial to a lower temperature position it either ignores me or after a few tries just shuts the heater off.
The end result is we either shut it off before going to sleep and wake up to a cold boat or leave it on and sweat the night away.
Is the controller broken? Does it need an external temperature sensor? Is there a more modern replacement where I could just set a specific temperature like one does at home?
As always, thank you in advance.
 
mixmaster said:
Hello,

I have an Eberspacher 5DL which runs just fine when it comes to generating lots of heat. The problem we have and have always had is that it seems to either generate too much heat or none at all. The controller (which looks like this one: https://www.pfjones.co.uk/modulator-switch-30100154.html) doesn't control the temperature very well. The unit is either on and when I move the dial to a lower temperature position it either ignores me or after a few tries just shuts the heater off.
The end result is we either shut it off before going to sleep and wake up to a cold boat or leave it on and sweat the night away.
Is the controller broken? Does it need an external temperature sensor? Is there a more modern replacement where I could just set a specific temperature like one does at home?
As always, thank you in advance.
Click to expand...
This type of thermostat senses the temperature on the return air inlet and we had the same problem as you with it being located in a locker. we changed to this controller which has a built in sensor and reacts to the temperature in the saloon where it is located. PF Jones will advise you which is appropriate for your system. https://www.pfjones.co.uk/eberspacher-digital-controller-80110003.html
 
akyaka said:
This type of thermostat senses the temperature on the return air inlet and we had the same problem as you with it being located in a locker. we changed to this controller which has a built in sensor and reacts to the temperature in the saloon where it is located. PF Jones will advise you which is appropriate for your system. https://www.pfjones.co.uk/eberspacher-digital-controller-80110003.html
Click to expand...

But the description which the OP linked to says that the thermostat has a built-in temperature sensor.
 
pvb said:
But the description which the OP linked to says that the thermostat has a built-in temperature sensor.
Click to expand...
yes but does not say that the sensor has to be connected to one in the unit in the return air, suggest you read the full technical specification. I have had one , had same problem and resolved how I said . When installed the original return air sensor is disconnected.
 
The DL is great but a little 'old hat' nowadays. I recall that the D models and I think the DL models were a bit crude in their ability to control lower temperatures and tended to shut down and then come back on again rather than slowing fan and pump to maintain a low heat.
akayka's solution could be spot on as he identifies a common problem.
Even with more modern heaters the setting control seems quite critical I have had to experiment just going down a small 'notch' at a time to get a stable lower temperature.
One solution is an extra sleeping bag and mount a switch where your ( or, better, SWIMBOS) arm can reach, roll over and get up when the cabin has warmed.
 
With the controller that I now have the fan starts slowing down as it gets towards the set temperature control setting and merrily ticks slowly away maintaining at that number.
 
If you are going to change the controller, then check to see if you can fit the sort that has a digital display, and can display the ERROR control codes. But be certain to confirm that this type of controller will work with your model Eberspacher.

The error messages are absolutely brilliant when it comes to fixing problems, they can tell you exactly what is wrong with your unit.

Good luck, George
 
mixmaster said:
Hello,

I have an Eberspacher 5DL which runs just fine when it comes to generating lots of heat. The problem we have and have always had is that it seems to either generate too much heat or none at all. The controller (which looks like this one: https://www.pfjones.co.uk/modulator-switch-30100154.html) doesn't control the temperature very well. The unit is either on and when I move the dial to a lower temperature position it either ignores me or after a few tries just shuts the heater off.
The end result is we either shut it off before going to sleep and wake up to a cold boat or leave it on and sweat the night away.
Is the controller broken? Does it need an external temperature sensor? Is there a more modern replacement where I could just set a specific temperature like one does at home?
As always, thank you in advance.
Click to expand...

I have the same very basic control.
There is not an instant response to adjustment of the dial although a change starts in a few seconds .
On a low setting the heater trundles along with hardly a sound and hopefully sipping the diesel. Maybe you just need to wait .
 
For this thermostat see:
/www.butlertechnik.com/downloads/Eberspacher_thermostat_controller_301_series_Instructions.pdf

Note: These instructions illustrate the use of the thermostats sensor
to monitor room temperature. Two alternatives are available:
#1) Heaters internal sensor - not available for D8LC.
#2) Remote external sensor- see technical manual for more details.
D5LC heaters may be supplied with this connector connected to the
heaters internal temperature sensor. This must first be disconnected
to allow connection to the thermostat. The D8LC switch harness by
default comes with the wiring for a remote external sensor, this must
be disconnected to allow connection to the thermostat.

Is your heater still using the incoming air sensor, not the room sensor?
 
pvb said:
Which model Eberspacher do you have?
Click to expand...

Model D2. When we installed the controller we cut the sensor wire on the return and connected, I understand this is common whether the ECU is in the unit or not. Best thing is to note the model number and serial number on the plate on the unit and raise the question as to the most appropriate controller with your local Eberspacher agent
 
akyaka said:
Model D2. When we installed the controller we cut the sensor wire on the return and connected, I understand this is common whether the ECU is in the unit or not. Best thing is to note the model number and serial number on the plate on the unit and raise the question as to the most appropriate controller with your local Eberspacher agent
Click to expand...

Fitting the 301 controller to the Airtronic is a bit different from fitting it to the D5LC. The link which Minchsailor posted has a specific wiring diagram for the D5LC, which the OP might check.
 
Eber's English manuals are not the easiest in the world to follow - there is marked lack of consistency in the translation of German technical words to their English equivalent. eg. 'controller' or 'control unit'. I have gone back to the original German manual to find out the true meaning. I think they have had different people doing the translations. It does not help that German technical writers have an austere way of using words.

I do wonder if your control unit has the room temperature sensing element fitted? The way the Eber works is that on switch-on if looks to see if the room temperature sensor is fitted (and approximately the right value); if the answer it is 'Yes', it uses that for control, if the answer is 'No', it defaults to using the incoming air temperature sensor on the heater itself.

Look at the wiring coming out of the heater itself. There should be a separate 2 wires (grey and brown/white) terminating in a 2 (or 3) way connector. There should be another 2 (grey/red and brown/white) wires from this connector going to your controller in the saloon. This is the temperature sensor.

If this connection is missing there is no temperature sensor in the controller.

Let me know how you get on.

The Eber room temperature sensor is a silly price; I can point you to an alternative (actually the identical thermistor) for a £ or 2, rather than £10s.
 
Wow. Lots of info here. Thanks guys. Have a 4 year old jumping on my shoulders so will have to give a proper read later.
Akyaka - Will give that web page a read and thanks for the advice. Is your D2 a newer or older generation model than my D5L (or a D2L for that matter)?
Martin G - no. there's definitely a lack of temperature control there. I've had this problem for 11 years!
Minchsailor - I'm pretty sure I'm using the incoming air sensor and that there is no room sensor. Will have to double check.

Looks like my solution is to either add a room sensor or just replace the control unit with one that has a built in sensor, digital temperature setting and the ability to give error codes. Now which one does that and is compatible with a D5L? Google here I come...

Thanks for the advice.
 
There are two different types of controllers to Ebers (I happened to read the other day). The older type are (it said) thermostats, the newer type rheostats. (To my thinking they are not necessarily different things: a thermostat could be a rheostat).

I guess they meant that the older type turns the burner on and off according to temperature, while the newer type (only available with some models) turns the burner up and down according to temperature (giving more comfort for less power).

I doubt this will help the OP, but it might clear up some confusion for others.
 
Ok. So the info on these controllers is pretty scant out there. Yes the D5L is a pretty old unit and all the info seems to cover the D5LC or the newer airtronic ones. Anyone know if there is a replacement controller that has an inbuilt sensor and digital temperature setting (error code reporting would be an added bonus)?
 
mixmaster said:
Ok. So the info on these controllers is pretty scant out there. Yes the D5L is a pretty old unit and all the info seems to cover the D5LC or the newer airtronic ones. Anyone know if there is a replacement controller that has an inbuilt sensor and digital temperature setting (error code reporting would be an added bonus)?
Click to expand...

I thought the information in the link in post #14 was fairly comprehensive
 
Look at the wiring coming out of the heater itself. There should be a separate 2 wires (grey and brown/white) terminating in a 2 (or 3) way connector. There should be another 2 (grey/red and brown/white) wires from this connector going to your controller in the saloon. This is the temperature sensor.

If this connection is missing there is no temperature sensor in the controller.
Click to expand...

Many of the Ex BT or commercial vehicle heaters or looms do not have this wire present.... It can be added, but needs some careful thinking about.
 
Not really. The controllers it does mention don't seem to be compatible with the D5L. But there are many other models available. However, no one seems to bother to mention if they work with the old heaters.
The web page on the link, informative as it is, has very little info on the D5L generation heaters.
 
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