This is a little discussion about diesel heaters. A motorhome without a good heater is not good any time. And in winter it is bad. Suzi motorhome had a diesel heater installed when she was built back in 2008. In recent times the heater started stopping occasionally – which was not good. We have had various chats with motorhome servicing places and finally got it sorted out last week in Dunedin.
Diesel heaters are good for motorhomes. They are very efficient, using a litre of diesel in 10 hours on low and 4 hours on high. Plus most motorhomes already have a diesel tank (for the engine). Plus they can be used when driving (whereas gas heaters shouldn’t). Plus they are a small unit which can be installed just about anywhere.
The negatives with diesel heaters include a higher purchase price than gas heaters, more minutes before the warm air starts to flow, a lot noisier on start-up and more noise when cruising, and a big hit on the batteries on start-up (peaking at 14-16 Amps – 12V).
Our heater is an Eberspacher Airtronic D2 which can produce 2 Kw of heat.
We like our diesel heater but for the last year it had taken to noisily shutting down and off. It would restart by switching it off and after a short while switching it back on. Someone in Blenheim thought it might need servicing. They said they removed them and sent them down to Dunedin for servicing. This wasn’t a good option when we were living in it in autumn so they put us onto someone else in Blenheim.
He thought we needed an extra fuel filter so we got one installed. This seemed to help but did not eliminate the shutting down problem completely. A few more noisy heater bail-outs as we were heading south gave us the impetus to visit the motorhome guys at Dunedin Motorhomes. They seemed to know what they were talking about and we’ve always had good dealings with them. We were happy to book Suzi in for a heater check and service and they did the work last week.
They found an internal fuel filter somewhat clogged and a fair bit of dust and not a lot else. They were able to interrogate the heater electronically and it was mostly happy with life and with itself which is good. It turns out that Dunedin Motorhomes is somewhere other motorhome places send diesel heaters for servicing and fixing – and we can see why. They are knowledgeable and efficient.
Now our little diesel heater goes like it did when it was new. It starts when it should, idles like it should, and only shuts down when we say so. Which is jolly good.
Over the last few years we’ve learnt and been told a few useful things about diesel heaters that are worth sharing.
- When turning the heater on, run it at full for 15-20 minutes before adjusting the thermostat lower.
- Don’t turn it on for a couple of minutes and then turn it off again.
- To avoid the voltage dip when the heater fires up run the motorhome engine so the battery is charging.
- Even better, if you’re going to be needing the heater when you arrive somewhere, turn it on 20 minutes before your get there.
- A diesel heater can only usefully have 4 metres of ducting (maybe that’s a 2 Kw unit?). And for each 90 degree bend reduce that figure by 1 metre!
- Install a fuel line out of the main tank and about 25% above the bottom. This avoids having a separate tank and means no risk of the heater emptying the main tank.
Any comments, contradictions and suggestions welcome.