We look after diesel air heaters across Sydney metro — Webasto, Eberspächer, Autoterm/Planar, Dometic, and the aftermarket units sold under a dozen different names. Service and repair from $360 plus parts if yours is smoking, refusing to start, running without heating, or throwing an error code. Installation $820 if you have bought a heater and would rather we fitted it.
A diesel air heater is a small combustion engine without the moving parts. It atomises diesel onto a glow plug inside a sealed combustion chamber, burns it, and passes the heat through an exchanger while a fan pushes cabin air across the other side. Exhaust goes out under the van. Nothing about that process is maintenance-free.
Almost every fault we attend traces back to one of three things: carbon building up inside the combustion chamber and on the glow plug, fuel delivery that has drifted out of spec or been interrupted, or voltage that sags too far during the start cycle. Short runs are the single biggest cause. A heater that gets switched on for twenty minutes to take the chill off, then switched off before it reaches full burn, never gets hot enough to clear its own deposits. Do that for a season and the chamber chokes itself.
Webasto (Air Top), Eberspächer (Airtronic), Autoterm/Planar, Dometic, and the large family of aftermarket units sold under names like Vevor, Belief and dozens of others. The aftermarket heaters are mechanically similar to each other and genuinely serviceable — parts availability is usually the deciding factor on whether a repair is worth doing, and we will tell you where your unit sits before you spend money on it.
From $360 plus parts. Diagnosis and repair of a heater that is already fitted — the faults below are what we attend most, and the visit covers finding the cause and putting it right.
Usually fuel or voltage rather than the heater itself. A heater that clicks, runs its fan, then gives up is typically not getting fuel to the chamber — an air lock after a filter change, a split line, a loose quick-disconnect, a pump that has stopped dosing, or a fuel pickup that is above the tank level. If the pump is ticking and nothing ignites, the fuel is not arriving or the glow plug is dead. These units also draw a heavy current while the glow plug heats, so a tired house battery can drop below the cut-off mid-start even though it reads fine at rest.
Unburnt fuel. Either the heater is getting fuel it cannot ignite, or it is getting more than it can burn. After a few failed start attempts, raw diesel pools in the chamber and exhaust and burns off as white smoke on the next successful light — that kind clears in ten minutes and is not a fault. White smoke that keeps going means incomplete combustion: a blocked combustion air intake, a restricted or crushed exhaust, a tired glow plug, or a pump over-dosing. Mud wasps nesting in an intake or exhaust outlet are a genuinely common cause on vans that have been parked up for a season.
Over-fuelling, or not enough combustion air. The excess that cannot burn bakes onto the chamber wall and the glow plug screen, which restricts airflow further and makes the problem worse. This is the fault that most often ends in a full decarbonise. Altitude matters too — a heater tuned at sea level runs rich up in the mountains.
A heater that lights and then stops after a few minutes is usually hitting a protection cut-out: flame-out detection, or an overheat sensor tripping because the heat exchanger is carboned up, the intake or outlet is obstructed, or ducting has been crushed behind a locker. Overheat trips are a symptom, not the problem — resetting it without finding the restriction just delays the next one.
The fan is working and the air moving, but it is barely warm. Either the burn is failing shortly after ignition and you are feeling residual heat, or the heat exchanger is so coated that it can no longer transfer heat into the cabin air. Occasionally it is ducting: a collapsed or disconnected duct dumping hot air into a locker or under the floor instead of the living space.
The dosing pump should tick steadily and quietly. A pump that has become loud is often mounted hard against a chassis rail or a locker wall, turning the van into a sounding board — it is frequently a mounting fix rather than a parts fix. Rattling or a change in fan note points to a fan wheel out of balance or fouling its housing, which needs looking at before it fails completely.
Worth knowing: error codes are not standardised between controllers. E-01 on one common LCD controller means under-voltage; on another unit the same code means something else entirely. So tell us the exact code you are seeing when you book, and bring the handbook if you still have it — between them it tells us what the unit is complaining about and what to put on the van before we drive out.
If the van smells of diesel when the heater runs, if the exhaust note has changed, or if the heater has started doing something it never used to, book the visit rather than waiting for it to fail properly. Fuel and exhaust faults do not improve on their own, and the cost difference between a service and a replacement unit is substantial.
The items that come up most often, worked through as the fault calls for:
Plus parts at cost. Allow 2 to 3 hours on-site for a straightforward service, longer if the unit has to come out of a sealed locker or a bed base.
One habit worth adopting between services: run the heater on its highest setting for ten to fifteen minutes before you shut it down, rather than switching off from low. The hot burn helps clear deposits instead of laying them down.
Book a service & repair · from $360 →
Bought a heater online and would rather not cut a hole in your own floor? We fit customer-supplied diesel air heaters for a fixed $820. You buy whatever unit you want — budget aftermarket or name-brand — and we do the install properly.
A heater visit pairs naturally with:
Yes — that is the whole point. Driveway, storage yard or caravan park anywhere in Sydney metro. We need access to the heater and its fuel and exhaust lines, a 10A power outlet within about 20 metres, and enough diesel in the tank to run a full test cycle.
Enough to run the heater through a full cycle twice, which is very little fuel but does mean the tank cannot be near empty. If your heater runs off its own dedicated tank, make sure there is fuel in it before we arrive.
Usually yes. Mechanically they are straightforward and a decarbonise plus a glow plug will bring most of them back. The honest caveat is parts: on some units a replacement control board or chamber costs a meaningful fraction of a whole new heater. We will tell you which side of that line yours falls on before you commit.
Yes — $820, you supply the heater. See installation above for what the price covers and what it does not.
Book the service. The visit includes diagnosis, and in most cases a recurring code is the unit telling you about a restriction or a fuel or voltage problem that the service addresses. If it turns out to need a part, you have the diagnosis and a quote rather than a guess.