Upfitter / Installer Guide to Working with Velit Gas or Diesel Air Heaters
If you are installing Velit Gas or Diesel air heaters for customer vehicles, follow these best practices.
The following topics are in no particular order but all relevant to make your experience as a Velit heater installer go more smoothly and best handled if you do run into problems.
Velit is the only air heater company with technical support that can assist with issues with our air heaters. BUT - to receive help you will be required to submit our Heater Support Request Form with as much information as possible. You can have your customer submit this form or you can submit it on their behalf. Then our technical support team can accurate diagnose and provide solutions - or have parts ready, for when/if the customer needs to bring their vehicle back for heater servicing.
Velit support does prioritize installers with support needs, but having the customer return and expecting Velit support reps to be on call, without providing information required in the support form first, will likely result in the customer needing to schedule/return for service a 2nd time at a later date, rather than being prepared to handle the issue on the initial visit by gathering required information before they show up.
Keep a spreadsheet of all components installed in customer vehicles being sure to note serial number and firmware versions most importantly.
If you or the customer require Velit technical support help in the future - Velit support will require to know the heater serial number and current firmware versions before we can accurately diagnose issues with the heater, or provide correct parts.
This is why you should note these numbers in a spreadsheet before you deliver the vehicle to the customer. Keep records of those numbers and provide them to the customer so they can contact Velit support directly with the required information.
Too often we see heaters installed in a way that the serial number cannot be seen on the side of the heater - or there is a problem with the heater preventing heater user from attaining the current firmware numbers, which requires additional labor to determine ECU version for correct firmware confirmation.
How to Check Firmware Versions on Velit Air Heater
Choose a heater install location in the vehicle that enables serviceability with the heater should any issues arise.
Gas and diesel air heaters can be some of the most finicky components in an entire RV build. They can also be very reliable when installed and operated correctly, going for thousands of hours without the need for any service. It's a bit unrealistic though to think once the heater is installed, it will never need to be serviced, so putting the heater in a difficult to access location is going to make for headaches in the future.
The most common example we see of this is installing a heater under the passenger seat of the Ford Transit, which is a very common install location. This location is extremely difficult to instal and service the heater due to tight clearances. So if you are installing a heater under the passenger seat of the Ford Transit, just know it will be a massive headache to access/remove that heater for servicing if needed. Instead, locate the heater somewhere else where it can be easily serviced if needed. Promasters and Sprinters have more room for heaters under the passenger seat, there are no major frame rails in the way below the vehicle.
The best heater install locations allow access to the top of the heater, as well as access to the bottom of the heater for connections with exhaust, intake, and fuel.
Manage customer expectations about heater operation and what to do if issues with the heater arise down the road and common error code handling.
Great article to share with new heater owners that describes the typical operation:
What happens during a normal operating cycle of a Velit gas or diesel air heater?
We often see technical support requests that are due to users not understanding the operating cycle of the heater, such as expecting instant heat after startup.
Be sure to explain that Error Code 01 and Error Code 02 are the most common errors with ALL brands of these heaters and does no mean there is a problem with the heater, rather typically something with fuel delivery. Advise that all Velit heater error codes require a fuse/power reset of 15+ seconds to clear the error code lockout, which is a safety feature. Show the customer how to remove power to the heater if needed for clearing error codes.
An E01 or E02 does not hurt the heater, so most often it just needs a reset, and the heater will start up and run successfully on the 2nd start attempt once the fuel has properly re-primed itself through a normal startup attempt.
Advise customer if they are having issues with E01 or E02 the first thing to do is to check for air bubbles in the clear fuel lines to understand how to fuel is making it to the heater. And explain after prolonged periods of not running the heater, it may lose it's prime and require a few startup attempts.
9 out of 10 technical support request we receive assume a problem with the internal components of the heater - but 9 out of 10 times the issues is not with the heater but rather user operational error or fuel delivery issues.
Avoid using looming on clear fuel lines. Or use sparingly at abrasion points only.
We do not include looming in our heater kits intentionally. We do not recommend covering clear fuel lines with looming of any type, unless absolutely required. Looming provides more problems than it solves and kills the primary diagnostic ability of the clear fuel lines and seeing air bubbles in the line that are most often the source of issues with these heaters.
We've seen fuel lines melted right through looming, where the looming is not melted but the fuel line inside is melted from touching exhaust or heat shields for example. So the looming hides the issues. Proper clearance should be given with fuel lines and hot areas under the vehicle. Looming is primarily for abrasion resistance at mount points, and should not be used to protect fuel lines from hot parts under the vehicle, they make heat shielding that should only be used in limited areas where there could be excess heat but not cover the entire length of the clear fuel lines.
Again, 9 out of 10 issues we see with heaters in Velit support are fuel delivery / fuel line related, and not an actual issue with the heater itself. If you are adding looming to fuel lines on installation you are doing a disservice to the customer and often hiding potential issues with improper fuel line routing and installation and eliminating diagnostic ability provided by the clear fuel lines.
If you cannot monitor the flow of fuel and air bubbles in the clear fuel lines because they are covered with looming, then you can not certify the heater is installed properly without measuring exhaust O2 which requires special tooling.
Manage customer expectations about cost of service if there are issues with the heater that arise down the road.
When you deliver a new heater instal to a customer you should advise them and manage their expectations about costs of service if they have problems with their heaters down the road, and be very upfront about this. We understand this is easier said than done but important to get ahead of.
This avoids a difficult situation of the customer paying you to install the heater, and then expecting free service down the road if problems arise. If you do not address this up front you will end up putting in more unpaid time if issues arise in the future.
We recommend you have your own policy on this such as being willing to inspect and help diagnose the issues, fix any issues with the installation, but that additional costs may arise for servicing the heater. Helping the customer understand that the heater worked after instal, but things can change down the road which is out of your control once that rig leaves the shop.
The most typical scenario we see is improper fuel delivery due to out of spec fuel line design, which leads to sooted up heaters coming back to the upfitter. In this case, the fuel delivery issues need to be addressed, by replacing the lines or relocating the fuel pump for example, but then the heater will also need to be serviced to have the soot knocked out of it for a fresh start with fuel delivery issues addressed. In this case, the customer will blame the heater or the installation and want free service, so getting ahead of this by managing expectations on heater servicing costs up front.
Again, we know this is a difficult situation for upfitters/installers, but if you do nothing to manage expectations about this, then it will be harder for everyone down the line and turn into finger pointing instead of solutions.
Follow specific instructions for installation specifications for Velit heaters, which may differ from other heater brands you've installed in the past.
We hear from upfitters that they have installed hundreds of heaters from other brands before but are now switching to Velit heaters and running into issues. When switching brands of heaters you'll also need to adjust installation methods to adapt to the spec of the new heater.
We recommend working with Velit support to verify installation methods when switching to Velit heaters from other brands. Our heaters use differently spec'd components such as fuel pumps, combustion chambers, and fuel lines. We also have specific requirements for fuel line routing for example.
Velit Air Heater Installation Checklist
Determine if you need to use a fuel filter or not, and if you do make sure to mount it in the right location and orientation.
Velit includes a fuel filter in our kits just to say we include everything you may need with an installation, but does not mean it's use is recommended or required.
There are a few issues with fuel filters that outweighs the potential benefits they would provide. Typically, we see them installed on the improper angle or position on the already inherently weak vacuum/pull side of the fuel lines.
These filters are meant to be used when there is known contamination in the fuel tank such as an old VW bus with rusted out tank. Typically, plastic tanks included with vans do not have known contamination and a fuel filter can be omitted in favor or shorter vacuum/pull side of the fuel lines and better fuel delivery.
Fuel lines, fuel lines, fuel lines.
As mentioned, 9 out of 10 support requests we receive end up being issues with fuel delivery from installation. Fuel line design is very specific and critical to reliable operation of these types of heaters.
Follow closely ALL the recommendations in this article:
Troubleshooting Fuel Line / Fuel Delivery Issues with Velit Gasoline / Diesel Air Heaters
If the heater comes back with problems due to fuel delivery, it's a good idea to plan on servicing the heater by opening it up and knocking the soot out of it for a fresh start. Addressing the fuel delivery issues without servicing the heater for a fresh start is only half the job. Same goes for cleaning out the soot, without addressing the fuel delivery issues that led to the problem, will result in a future sooted up scenario. Once heater is removed, it can typically be fully disassembled, cleaned, and put back together in only 15 minutes by a competent technician. Which means the hard part is removing the heater for service, so install them in a serviceable location.
Stock extra correct fuel line and gaskets to be prepared for these cases.
Understand firmware versions and when to upgrade or not on a Velit air heater.
Firmware is different than software in that if it's not broken then do not update it. You do not need to always be on the "latest version" if things are otherwise working as expected and the "latest version" depends on specific components in the heater like ECU version.
We have this document that makes versions available for upfitters reference:
Understanding ECU Firmware Versions for Velit Gas / Diesel Air Heater
It very rare that issues related to Velit heater operation are due to outdated firmware versions, but you can always check with support@velitcamping.com to be sure.
You can and should always check with Velit support before attempting to upgrade or make changes to firmware on a Velit heater. You should ALWAYS note current firmware version before changing firmware and note what firmware the unit was changed to.
Use the metal fuel standpipe included with heater kits, and/or advise customer on how fuel delivery works with this type of heater.
Sure, there are many many Velit heaters running on the aux. fuel ports of Sprinters, Promaster, and Transit vans without issue, but we always recommend using the metal fuel standpipe included with our kits for the most reliable combustion and performance of Velit heaters.
Even if a heater works on an aux fuel port, that does not mean that it is running perfectly as it should be to avoid soot buildup happening slowly over time. Additionally, we often see heaters that run on aux fuel ports instead of metal standpipe have more frequent issues with Error 01 and Error 02 from sub-prime fuel delivery.
If the heater fails to reliably start/ignite, or soot buildup happens from running the heater off an aux. fuel port slowly over time at elevation - then not only will the metal standpipe installation be necessary but also servicing the heater to knock the soot out of it will also be required.
Advise customer on avoiding over-priming the heater.
DO NOT OVERPRIME!
We include a "prime" mode on our air heaters that allows manual priming of the fuel lines. Typically this feature is not needed when fuel line length is less than 6 feet. But since there is nothing restricting fuel flow after the pump, and prime mode runs the pump at the fastest speed for 30 second unless stopped early, it's very easy to over-prime these heaters, which can get messy especially with diesel which does not evaporate like gasoline does.
Prime mode should only be used when monitoring the fuel flow in the clear fuel lines and should be stopped once the fuel has made it past the fuel pump.
Prime mode should not be used to "push" air bubbles out of the system.
If priming is needed, we recommend running the prime from the phone app, and monitoring the fuel's progress in the lines and turning it off before the fuel reaches the heater to avoid over-priming.
Advise customer on general maintenance of heater and how the heater is cleaned if required.
Velit air heaters clean themselves by running on manual mode high for 20+ minutes. All the "cleaning mode" does is heat the glow plug and run the fans, which can be helpful in a over-primed situation to dry the glow plug.
In general, if fuel delivery is optimal, cleaning should not be necessary. Try to avoid short cycling the heater which can happen from only ever running on low for short periods. These heaters like to burn hot. These heaters can have thousands and thousands of hours on them, do not be afraid to use them often as possible.
During the cooldown cycle, the glow plug is heated one last time to clean itself off, and on gasoline units small backfires can be heard as unburned fuel is ignited, which is normal and ok.
See this article on when and how to clean a Velit air heater:
Get comfortable servicing the heaters by taking them apart to knock out soot with dry brush after a sooted up scenario.
Once a Velit heater is removed from it's mounting plate, it is extremely easy to disassemble and clean out. Pretty much only 11 bolts and the whole thing comes apart. Cleaning soot out of a Velit heater can be a very quick and easy process - in our service center we can do this in under 15 minutes once the heater is removed.
We recommend using a dry brush to knock the soot out of the heater, as carb/intake cleaner spray can make a mess and result in a smokey startup until it burns off. Diesel units will often have a wetter soot, where gasoline units usually have a more dry soot since gasoline evaporates.
Do not lose the glow plug set screw and ball bearing! Only turn the glow plug set screw 1/2 turn and pull the glow plug out, and turn the set screw back in tight immediately after glow plug is removed.
Cleaning the soot out of a Velit heater without addressing the issue that led to the soot buildup is just asking for more issues down the road. Addressing sub-prime running conditions must be part of cleaning the soot from a heater.
Soot buildup generally does not hurt the heater, and once it's knocked out, the heater can go on to run many thousands of hours without issues if the problems that led to the soot are correctly addressed as well.
Advise customer about running the heater in the summer to pull fresh fuel into the fuel lines to avoid fuel going bad in the lines.
Gasoline varnishes from ethenol content in as little as 1-3 months time. With the clear fuel lines we use, if you do not run the heater for 3 months you can see the degraded fuel color in the fuel lines.
It's recommended to run the heater for 20+ minutes every month or two during summer months on manual mode to pull fresh fuel into the fuel lines. Otherwise if you do not run the heater all spring summer and early fall, and go to start it up in the winter - you will jam a bunch of gelled up fuel into the heater which can lead to issues not present at the end of the past winter season. Be proactive with this, use your heater all year long as you are able.
Stock spare heater gaskets and correct fuel line to have on-hand for servicing heaters you've installed.
If a customer is returning to your shop with issues with a heater you installed, you need to be prepared with the basics required for servicing their heater. This usually involves inspecting, replacing fuel lines, and servicing the heater to knock the soot buildup out so it can have a fresh start with sub-prime fuel delivery issues addressed.
Sometimes our gaskets are able to be reused, but having them on hand is the best plan if needing replacement.
Correct fuel line is not something that can be sourced locally so haveing the right fuel line on hand is critical as 9 out of 10 issues we see in velit support are related to issues with fuel lines/fuel delivery and remaking the lines is the way to rule out potential unseen issues with them.
Gaskets are standard and can be sourced from sites like Amazon for fastest delivery:
https://velitcamping.com/products/velit-heater-internal-gasket-set
If the heater is covered under 2-year warranty, Velit support can usually provide these gaskets but will be subject to shipping and handling times.
How Velit differs from other gas and diesel air heater companies.
Customer appreciate that Velit heaters are about half the cost of the german alternatives (Webasto, Espar). But that's not all. Parts are covered under 2 year warranty and they are typically available and shipped from within the USA. Parts for the German heater brands typically are very costly and need to be shipped from the UK or Europe.
It is very uncommon for internal heater components to need replacement but they are typically much more affordable than the other brands. For example, Webasto / Espar fuel pumps and combustion chambers typically run $450 as to where those parts for Velit heaters are around $60 cost. Huge difference.
Most importantly, Velit is the only heater company with tech support engineers that can assist with technical support for Velit products. We are very successful with correctly diagnosing issues, and making parts available if needed. Tech support is typically not available on-demand and we require a form fill similar to a doctor's office, where our engineers can call with solutions after being provided all the relevant information.
Velit support does prioritize installers and upfitters who we have a relationship with as they support many customers. Again, it's important to plan for customer visits for repair at your shop, and manage their expectations about solutions and waiting on parts - depending on how much can be diagnosed and planned before their arrival.