NV200: Fitting Diesel heater

This was probably my most feared job.  Not because its complex, or that never seen one let alone installed one, or its expensive and a host of other reasons.  The main reason is having to get into the fuel tank and I’m scared of breaking the vans fuel system….

And, in fact it was the biggest **** of a job too 🙁  Not just because of the issues I though above, but the ****ing box I made which fitted perfectly when dry fitting.  But when the heater was installed you could not access the nuts to fix it.  Doh #1.  And the fact the heater was installed on some wood not raised on the metal base, it bent the plastic a bit and jammed the fan (not found till I thought I’d finished).  Doh #2.  And it was impossible to access all the pipe connectors easily.  Doh #3.  So it was a nightmare, topped off by me getting a load of permanent bonding goo in my hair.

Anyway, here is the working solution which with the benefit of hindsight, is just as good and has easier maintenance options.  Still – what else was I going to do for a couple of days (!).

We opted for a MV airo diesel heater from Kiravans, which is cheaper than the other makes and includes everything you need including digital and “sort of” programmable controller.  The heater can be installed externally or internally, but we want it internally.  The problem is that the heater needs a hole to the outside for fuel, air intake and exhaust.  And in a small van like the NV200 there are very very few places where it can go, especially (like us) if you have water tanks underslung.

You can have it behind the passenger seat, but that’s where our waste tank will be….

We’ve opted to have it between the driver and passenger seat, and build a strong box we can step on to get in/out of the cab.  In addition, the top of the box will be a low “coffee table” for me when I’m in the rotated passenger seat.  However, in this location, there is a van wiring loom and, I think, the rear wash/wipe washer pipe!   And the floor isn’t flush so installing the heater in the normal way is impossible.

I contacted the makers of the heater, and they assure me it doesn’t get hot enough to melt cables (except exhaust which is fine), and that we can raise it and not have it flush to the floor.

Between the seats, there is a grommet which is unused, this will be for the air intake (nearest the van loom), and we’ll drill a new hole towards the back of the van for the exhaust and join them up.  The hole needs to be quite a bit bigger than the “holes” in the metal plate, but not as big as the big circle.  Looking at Kiravans install we didn’t get any closer to the seat mounts than they did, and 99% of the hole is in single skin metal, so don’t think we have got too close to the mounts.

But, not being level, and looms everywhere, there is a challenge to get the thing in still!  So the provided installation frame (flat metal and round tube) is going to be installed entirely internally.  So bonded to the van floor is 15mm ply with the appropriate size holes (with 3, 9 and 15mm shims!).  Then, a 9mm ply glued n screwed (IGNORE PHOTOS WITH vertical bolts bonded in – this was a duff idea!!!), and then a final 9mm ply “base”.  In addition, under the front we have a small gap for a services run for the waste tank pipe and electrics

These are sealed to the van floor so nice and air-tight and water tight.

The metal heater frame I drilled smaller holes nearer the edge, and fixed it to the heater using the rubber gasket.  This raises it a few mm and I guess adds sound/vibration protection.  You must use this plate, else if heater chassis on flat it can jam the fan.

The heater is screwed via the new holes to the wooden frame and this means the connections to the heater are accessible and it is easily removable for maintenance or repair.  The heater can be connected to intake/exhaust/fuel and then dropped over the bonded frame and screwed in.  Again, future maintenance should be easy.

The box now goes on top of the heater once the heater is installed, held with corner brackets.

The box ends are in the air, so for the cold intake/engine end I’ve bonded support wood next to the “sticking up threads” for it to rest on, and the habitation end a small support to sit on the new floor.

With the box made out of 15mm ply, it should easily take our weight moving in and out.

The box is glued and screwed with pocket holes.  The top has some worktop laminate on top and trimmed with the furniture trim we will use.  The lid is “tight push fit” so very tight but will come out for maintenance.  This is my first attempt with the trim edging….

Inside the box, the heat is sent direct into the habitation area.  The air inlet is not connected, so it will suck air from the cab AND from inside the box.  This will help keep the box cool and minimise heat soak.

The electrics all wired up as needed.

The fuel intake is a challenge.  The access panel in the rear of the van behind the drivers seat reveals the cover to the tank, removing this gives access to the top of the tank.  I’d suggest disconnecting the battery before fiddling, and then remove the power lead and the two fuel pipes come off easily by depressing TWO buttons – opposite each other, then slight twist and pull off.  Ours wasn’t under pressure and just had a drips out.

The top of the tank needs to be unscrewed but you need a special tool – get one first!  Banging with a hammer may work but don’t risk it.  See my “essential tools” link at the top of the page for some options.

Once unscrewed the fuel sender just pulls out – bit stiff but its a big gasket.

Once out, easy enough to find a good spot to drill a 6mm hole and put in the fuel pick up (cut at c. 19-20cm) and bent around the bits.  Note the sender unit compresses to 19cm.  Check it doesn’t hit the float sender.  And reassemble.

The Euro 5a engine has a fuel primer under a panel under the drivers seat (RTFM) – but ours has the panel but no primer, so assume its Euro 5b which apparently self primes.  So, after reconnecting the battery, I turned on ignition 3 times waiting for the fuel pump to run/prime, then started the engine up and it ran fine.

Connecting the heater fuel filter and pump is trivial, and I made an aluminium bracket to hold it and prevent stone damage, and also to hold the excess pump cable.  The pump is angled around 15′ as per the manual.  The pipes then connected as per the manual.

The heater does have a prime function so temporarily wired it in and ran the prime till fuel came out, and then connected to heater.

Hey presto works a treat!  Note the controller LOOKED like it was in error code, showing P-07.  This actually was in manual power mode (!).  The manual for this is naff, but pressing up & down together put it into thermostat mode.  Phew.

However – some pics may show version 1, not version 2 – so read above not follow pics.  make a bigger hole than you see – I had to enlarge it and it looks like a dogs dinner, but then put an aluminium neat edge underneath and bonded that in so it looks really good.  But covered in plenty of primer and plenty of waterproof permanent adhesive, so should be okay.

Was a v v long day or two and should’ve taken just a few hours – not an easy job.

Finally, the center console tray was cut to fit, and the final thing is use some convoluted pipe (when it arrives) to make the heater wires neat (they will be in a service tunnel anyway)

Phew.