Eberspacher Heater is there a fix?

[Alan Ginger]

Wonder if you could help me out here?

As highlighted in my and others previous postings the Eberspacher heater thermostat has to be set at something like 7 degrees below the required van temperature as the heater draws the air from the footwell which is colder than the air in the habitation area. The heater keeps going until it detects that the air in the footwell has reached the required temperature Set at the thermostat.

As it was described to me a bit like a thermostat at home, you set it to 18 degrees but not every room in the house reaches 18 degrees ( that is how it was explained to me by my van conversion builder )

Although I have not tried this solution myself when I set the thermostat to 20 degrees at the weekend the van did became a bit warm when it reached 28 degrees.

The thing that irritates me is that: if I bought a £50K VW car and they told me the heater did not work perfectly I would ask them to fix it.
The company that sold me the van ( they were not the builders ) are trying to help resolve the problem.
Does the same problem occur in the VW California?
Does anyone know of a solution to this problem?

As usual thank you for your help.

 

[t0mb0]

Pretty sure in our van the thermostat is on the display/control gizmo which is well away from the heater itself? It would seem wrong for the thermostat to be situated too close to the heater output. I’m sure someone will be along who knows more than me about the specifics of it though.

 

[Niknak]

What thermostat do you have as all eberspachers I’ve worked on the thermostat is totally separate like a house thermostat and has no bearing on the air temp in the footwell

 

[Alan Ginger]

Pretty sure in our van the thermostat is on the display/control gizmo which is well away from the heater itself? It would seem wrong for the thermostat to be situated too close to the heater output. I’m sure someone will be along who knows more than me about the specifics of it though.

Many thanks t0mb0 my thermostat is up on the wall away from the heater. The thermostat is an 801.

 

[Niknak]

I’ve had loads of eberspachers apart and probably service them every other week and I’ve never seen a internal thermostat of any kind I’m sure your being fed some bs

 

[airhoguk]

Don’t forget the thermostat will be partially affected by the surface it’s mounted to especially if it’s built into the timer so the surface it’s attached to also needs to warm up such as your vans furniture. Remote thermostats are available that will react better as they aren’t attached to large heat sinks

 

[Alan Ginger]

What thermostat do you have as all eberspachers I’ve worked on the thermostat is totally separate like a house thermostat and has no bearing on the air temp in the footwell

many thanks the thermostat is on the wall away from the heater. Though the heater draws the air from the footwell as I understand it and there is a sensor in the heater.

 

[Niknak]

Many thanks t0mb0 my thermostat is up on the wall away from the heater.

I’m confused you say your thermostat is on wall away from heater but what are you meaning about when it detects the cold air in the foot well you speak of, one problem I’ve seen with lots of instals is converters mount the thermostat not far from the windows and sunlight floods the thermostat and heats it up and therefore shuts off the heat

 

[Alan Ginger]

My thermostat control panel is on the side of the wardrobe well away from the heater unit. I set the control panel to say 18 degrees and the heater continued to put out hot air until the control panel shows 28 degrees

The builder told me that this happened because there is a sensor in the air intake of the heater and the air in the footwell where the vent is much colder than the rest of the van and the heater will continue to churn out hot air until 18 degrees is reached in the footwell by which time it is 28 degrees in the rest of the van.

So the solution that was presented to me was to set the thermostat to 13 degrees and the van will be heated to around 20 degrees.

is this BS or accurate and is this the only solution to the problem.? I.e set the thermostat to 7 degrees less than you actually require.

 

[Niknak]

What model have you got

 

[Alan Ginger]

What model have you got

The Heater is a D2 Eberspacher and the control panel is 801.

 

[Niknak]

The only reason you should have a intake air temp sensor is if the air intake is exterior or not in the area being heated

 

[Alan Ginger]

The only reason you should have a intake air temp sensor is if the air intake is exterior or not in the area being heated

so when the builder said the heater was drawing air through a vent in the footwell this is not correct.
what then would be the solution?

niknak thanks for taking time to reply.

 

[Niknak]

No it may be drawing air from footwell without seeing it I could not tell what’s been done

 

[oldiebut goodie]

Oh dear here we go again ..... it is a heat controller not a thermostat, that is why it does not behave like a thermostat. I do wish people would not refer to heat controllers as thermostats, thermostats have not been used on heaters for quite a few years now.

I keep telling people that the controller compares the set point of your setting with the temperature of the air at the heater intake unless you have an external temperature sensor fitted ( usually at mid-heightish in the van) It does not matter what the temperature is that you set the controller to it is just a number, it would be better to not have degrees mentioned on it for standard fitment. Your setting on your standard fitment controller is the temperature that the heater is trying to achieve at the intake not at the controller position - I wish that this fact could be pinned to save me keep saying it!

 

[Alan Ginger]

Oh dear here we go again ..... it is a heat controller not a thermostat, that is why it does not behave like a thermostat. I do wish people would not refer to heat controllers as thermostats, thermostats have not been used on heaters for quite a few years now.

I keep telling people that the controller compares the set point of your setting with the temperature of the air at the heater intake unless you have an external temperature sensor fitted ( usually at mid-heightish in the van) It does not matter what the temperature is that you set the controller to it is just a number, it would be better to not have degrees mentioned on it for standard fitment. Your setting on your standard fitment controller is the temperature that the heater is trying to achieve at the intake not at the controller position - I wish that this fact could be pinned to save me keep saying it!

Excellent my friend oldie but Goodie: It would be good if it was pinned somewhere. I have got it.
So the solution is: an external temperature sensor.

Many thanks again troops this is why this site gets a thumbs up from a total newbie like me. Cheers Alan

 

[Niknak]

Oh dear here we go again ..... it is a heat controller not a thermostat, that is why it does not behave like a thermostat. I do wish people would not refer to heat controllers as thermostats, thermostats have not been used on heaters for quite a few years now.

I keep telling people that the controller compares the set point of your setting with the temperature of the air at the heater intake unless you have an external temperature sensor fitted ( usually at mid-heightish in the van) It does not matter what the temperature is that you set the controller to it is just a number, it would be better to not have degrees mentioned on it for standard fitment. Your setting on your standard fitment controller is the temperature that the heater is trying to achieve at the intake not at the controller position - I wish that this fact could be pinned to save me keep saying it!

These are the ones I’ve been using for years at work
And they work as a thermostat they click in and click out

 

[oldiebut goodie]

Here is a list of the various parameters that I have just pulled from a Webasto ecu that I have just connected up as an example - you can see the various temps that are measured in the list:
The temperature being measured by the external temp sensor is 17 degrees, the temp of the heater heat exchanger is 21.2 degrees, the circuit board is at 20 degrees, the temp at the heat controller is set at 17.6 degrees and the temp being compared at the intake sensor is 15 degrees. The differing temps are mainly to do with being in a warm room and the heat exchanger has retained heat longer than the intake sensor when my central heating radiator was on earlier.

 

[oldiebut goodie]

These are the ones I’ve been using for years at work
And they work as a thermostat they click in and click out

View attachment 114172

That is a thermostat - they are not used nowadays. They are only used on museum pieces now.

 

[Niknak]

That is a thermostat - they are not used nowadays. They are only used on museum pieces now.

Hmm still fit them at work they are requested, they won’t have anything else