Diesel heater location

Submitted: Friday, May 18, 2012 at 16:41
ThreadID: 95647 Views:6850 Replies:6 FollowUps:3
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I am thinking of getting a diesel heater installed but not sure of the best location as have limited space.

My options are

Under a seat where I currently have a gas HW unit
Under the bed in my only free storage compartment.

I am not sure if installing with the HW is safe but would fit.

Under the bd would be ok but I will lose my storage area , well may be.

Could I build a box over the heater then I can store things on top of it or next to it.

I guess this depends and this is my main question, how. Confined can these heater be and how much heat is generated from the unit to areas surrounding it.
Do I need additional ventilation or clearance other than those from the pipes of the unit.

Hope all that makes sense and thanks for any help,

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Reply By: Ozhumvee - Friday, May 18, 2012 at 17:13

Friday, May 18, 2012 at 17:13
They Webasto Thermo Top diesel heater/HWS does expend a bit of heat so should not be in an enclosed space, they are designed to be fitted underbonnet or under vehicle.
The ones I think you mean are the Airtop type air blowers which can be fitted pretty much anywhere, I've seen them in 4wd buses under the seats etc as they draw combustion air from externally and exhaust externally, only the heated air is sucked from the passenger compartment, heated and blown back into the passenger compartment.
They do need to be mounted to either floor or wall so that intake and exhaust piping can pass externally.
If you go to the Webasto site you can download the installation instructions.
AnswerID: 486150

Reply By: Member - Captain (WA) - Friday, May 18, 2012 at 17:18

Friday, May 18, 2012 at 17:18
Hi Richard,

My Quantum has the diesel heater, gas HWS and electric a/c all installed under the same seat, a relatively small area. Even the water filter cartridges (2 x 10") are there too. Seems to work fine and there have been no issues.


AnswerID: 486151

Reply By: Member Boroma 604 - Friday, May 18, 2012 at 17:34

Friday, May 18, 2012 at 17:34
We have had one, (Webasto), for several years, my advice would be under the seat, I imagine seating is along the side of the caravan, it would not pay to put it in a Box, I do no think, they do not get hot on the outside, well ours doesn't anyway, however they need to be able to breathe where you install them, would pay you to put an Air Filter on the internal air intake to catch fluff that may accumulate on the fan blades. Also be sure you have muffler fitted on the exhaust outside.
If you have an outlet under the seat you will find that will be sufficient for a caravan.
Hope this helps,
AnswerID: 486153

Reply By: Dust-Devil - Friday, May 18, 2012 at 18:01

Friday, May 18, 2012 at 18:01

I have installed one of these doovers in our caravan under the seat which contains the HWS and Electronic Black Box that controls all 12/240V switching.

They do not radiate heat externally, however they do need an unimpeded airflow over the heat exchanger.

These units require a hole approx 6" 150mm (from memory) to be cut in the floor of the van. This is for exhaust and fuel lines which enter/exit the unit from the bottom of same via a heat shield ring. It's the 'ring' that requires the hole so that the unit fits flush through the floor of the van.

The biggest problem you will come up against when trying to identify a suitable location is finding a spot that (a) is out of the wayin the van & (b) has a space under the Van clear of wiring, gas pipes, water lines etc etc.

Our Jayco Base Station is an absolute nightmare of stuff under the floor which required a slight re-arrangement to fit our heater into.

The second issue you will face is where to put the fuel tank. I have a inherent fear of the fuel being tampered with so have currently located the fuel tank in the front storage tunnel which works quite well.

The third issue you will encounter is the wiring requirements. Mainly being able to locate all the required wiring without it being seen, including the controller. Not hard, just time consuming and fiddly.

Other than that the final result is just exceptional. I have split the output of ours so that we have two zones which works really well.


AnswerID: 486157

Reply By: Member - Rich - Saturday, May 19, 2012 at 01:02

Saturday, May 19, 2012 at 01:02
Thanks all for the comments.

It does seem like the area with the HW is the way to go. It is by far the easier access area.

AnswerID: 486192

Reply By: MEMBER - Darian, SA - Saturday, May 19, 2012 at 09:02

Saturday, May 19, 2012 at 09:02
A bit 'off question' but have you considered the Truma gas version of van heating ? Think I'll go that way when I get heating - mainly because gas is already on the van - much the same super-efficient technology via the same very compact furnace and control panel.
AnswerID: 486201

Follow Up By: Member - Rich - Saturday, May 19, 2012 at 09:26

Saturday, May 19, 2012 at 09:26
I sure did consider the Truma and was going that way myself and at this stage it is still a possibility.

The reason I am leaning towards the diesel now is
1. My car runs on diesel
2. I do have gas to run the HW and stove but I only have 2x 4.5KG bottles. I believe the Truma are efficient but would have felt more comfortable if I had 2 x9kg as gas is not as readily available in some places.
3. A simper install , I think
4. More common

The reasons I liked he Truma
I would only have to worry about one fuel source but have the concern above
It was not as noisy however I think you can put a muffler on the diesel now.

Not major issues I know but it comes down to the gas supply. I looked at changing to 9kg bottles, not a big expense but they don't fit unfortunately.

Either way the issues are the same, where to locate it.

From my reading and research the gas is just as good in all other aspects and is a good choice.


FollowupID: 761442

Follow Up By: Member - Rich - Saturday, May 19, 2012 at 10:00

Saturday, May 19, 2012 at 10:00
I gave some more thought to the Truma.

As mentioned I already have a gas HW. One issue I have had with it is the cowl outlet. It comes out on a checker plate surface and it has been a real pain keeping dust and other stuff out of it.
The Truma is a bit bigger s well and am not sure it will fit and locating it's cowl may be difficult.

The diesel outlets can go through the floor.

I suspect these are all resolvable but not by me :).

FollowupID: 761445

Follow Up By: MEMBER - Darian, SA - Saturday, May 19, 2012 at 13:48

Saturday, May 19, 2012 at 13:48
Yes - as you say, many factors are included in such planning - I'm on diesel and have carted and dispensed fuel from jerries quite a lot - I had in mind those pesky little stinky diesel spills that would be a real nuisance if the heater tank is in a compartment - I've seen DIY installers put the heater tank on the outside of the van, for this reason. For longer periods where the heater won't be used, I think the fuel might need to be purged to avoid algae growth etc. - there is a fair bit on the Caravanners Forum re this topic. For offroaders, dust rears it's ugly head as an issue - the in/out vents need to be effectively closed on either fuel system, so that the furnace stays quite clean - dust has caused quite a bit of angst for some owners.

FollowupID: 761458

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