Coninuing Eberspacher Problem

[rhodgkinson]

Many thanks for your response to my earlier thread: I did pose another question, which I guess didn't attract your attention.

I have now had time to spend an hour trying out your suggestions. The thermostat on top of the blue tank is set at 64 and that is the setting at which I received delivery. With the mains plugged in and the thermostat dial of the inside control unit set at max, I tried running the heater several times.

Each time it seems to light. The fan runs at maximum, the air being pushed out takes about 5 minutes to get decently warm, runs for a total of about 15 minutes and then the heater seems to go out: the air coming out gets cooler and there is no exhaust coming out of the exhaust pipe. All this time the fan runs at max. Each time I ran it like this for a further 10 mins, but no change.

Even when it was running at its hottest, the air being pushed out was no better than decently warm, and not as hot as I remember it running a year ago. Any further suggestions?
Thanks,
Richard.

[ant]

Hi Richard.
It sounds as if the heater is shutting off rather that shutting down to tick over. I have had a similar problem in the past, the cause was a kink in the combustion air inlet pipe, ( something had knocked it underneath and bent the pipe) I suppose a kink in the exhaust pipe would do the same thing and make the heater shut off. If the unit senses an incorrect mixture of air/exhaust/unburnt diesel it will stop heating and blow at full speed to cool the unit.
If you find no obstuctions then I'm affraid you do need to get it plugged into an eberspacher diagnostic machine to ask it "whats a matter".
Ant

[rhodgkinson]

Many thanks for your advice which led to a tale of woe and lessons for others. As I had bought my Hylo from Freeborn I approached their Godalming Branch with my problem explained above. They told me that they had two fully qualified people who would be able to fix it and they at the same time persuaded me to have a habitation service. I was a little concerned when I mentioned your comment about plugging the Eberspacher heater into a diagnostic machine, when they said there wasn't such thing; but I assumed they knew what they are talking about. In they event they weren't able to fix it and I was £205 the poorer. They gave me a list of Eberspacher dealers, all of whom were miles away. When I checked my own Eberspacher documentation I discovered that there was one nearby, right on their doorstep just outside Guildford. I am tempted to think that they missed it off their list on purpose but I will give them benefit of the doubt now that I have been onto the Eberspacher website and seen the list of dealers, where the Guildford dealer was last on the list and may have been missed off by accident.
The authorised dealer did have a diagnostic machine and showed an error fault with the heat sensor. This was replaced (not cheap) and the whole job, testing it with the diagnostic machine, taking the heating unit off the vehicle, servicing and replacing the defective part, testing it on a test bench, refitting on the vehicle and testing it on the vehicle required about 4 hours of labour. But the job was done.
It was useful to learn from the service engineer:
- That the control unit for the heater is wired directly into the domestic battery: I had always religiously turned on thee Electrics Control Panel to the domestic battery on position before turning on the heating unit.
- Running the vehicle engine, even driving, with the heater on is perfectly OK, and is in fact desirable when you start the heater to ensure the correct voltage for starting; whereas the Eberspacher instruction manual says on no account run the engine when the heater is on as you will risk blowing all sorts of fuses.