Webasto Air Top 2000 ST T1N Underseat Install

Hello everyone,

I'm looking to install the aforementioned heater in a T1N Sprinter, specifically a 2005. I've done a good amount of reading on this forum on this topic, however I haven't found a good, clear document of how the install process goes. I've found some good info for the Espar, would this information be about the same? I'm inexperienced in this process, but have a good mechanical mind and knowledge base. My van has an aux heater onboard and I'm currently planning on tapping into the fuel line for the aux heater. I guess my question is what is the process like for installing this heater? Any tips for how to tap into the fuel line and which fittings to use to do so? Overall tips when it comes to the install? Links to solid posts about this process? Any sort of information that someone experience has to give will be greatly appreciated. I thank you in advance for your time.
 

YoungRovers

New member
I just finished doing this as well...the T1N doesn’t have anywhere to tap into... needs the tank dropping and a standpipe installed...I installed mine so that it sits about and inch or so off the bottom this way it doesn’t suck any debris up and I can never leave myself out of fuel... I will be posting some pics up soon on or website..www.SprinterEnvy.com . Our website is informational only to share with like minded sprinter DIYers...
 

eagle2232

New member
The install procedure and considerations are very similar to the plentiful Espar D2 info found in many Forum posts, as well as the installation documentation included with your heater:

1. Determine your best desired install location relative to your overall build layout, with consideration to fuel line tap-in, air intake space, heat outflow direction, and the 3 needed holes through-the-floor (exhaust pipe, fuel line in, electrical pump cable) and secure mounting bolts. I chose ahead of the driver side rear wheel well for my T1N.
Espar install.jpg
Espar install 2.jpg
2. Drill holes per holes template. File, prime, and paint bare metal.
3. Mount the heater's pump in the undercarriage of the T1N. I mounted my D2's pump to the body frame very close to the T1N's fuel line tap location, located underneath below and behind the driver seat (see attachment) copying same method of another T1N build shared here on this Forum. And also copied his assembled brass barbed "T" to tap into the existing fuel line. Brass parts from Lowe's.
View attachment d2 T1N fuel line tap location.pdf
Image from another T1N build on this Forum
Espar D2 fuel tap in.JPG
Brass barbed T to tap fuel line.jpg
4. Determine mounting for the exhaust pipe. I mounted underneath, by the rear axle driver side.
5. Tap into the T1N existing fuel line with the brass barbed T. A smart tip is firmly pinch the fuel line behind the fuel filter in engine compartment to minimize fuel drain out when you cut the line for the T fitting. This maintains vacuum pressure when you tap into the T1N existing fuel line. Use small hose clamps to secure the fuel lines to the brass T.
5. Dry fit the Heater in place, and remember it's easier to attach the exhaust pipe and fuel line before final bolt down of the heater.
6. Secure the running length of the small plastic fuel line from pump to heater along the undercarriage. I encased it in 3/8" wire loom for protection, and zip tied to 3/8" cable clamps spaced 8" apart attached under the driver side undercarriage.

I reiterate Hein's statement in his post where he mentioned "Proper fuel delivery is important to the operation of the D2. Long fuel line runs can cause problems. The fuel pump must be located near the tank so the suction side is short. You might be OK reaching to the back of a 144WB but will likely use all the small plastic line which cannot be extended, substituted or spliced. A preferable location may be ahead of the LH side rear wheel well."
https://sprinter-source.com/forum/showpost.php?p=322150&postcount=9
 

YoungRovers

New member
I looked into tapping into the existing fuel lines and couldn’t get anything more than a cup full of fuel out of it I simulated a fuel pump suction with a mityvac to verify that there is free flow and there was not...if it’s the pressure line you can’t suck past the pump and the return line either has a check valve in it or it doesn’t return into the base of the tank...
 

lindenengineering

Well-known member
I looked into tapping into the existing fuel lines and couldn’t get anything more than a cup full of fuel out of it I simulated a fuel pump suction with a mityvac to verify that there is free flow and there was not...if it’s the pressure line you can’t suck past the pump and the return line either has a check valve in it or it doesn’t return into the base of the tank...
What you are writing scares me.
On any Sprinter with a pressurized fuel system you cannot tap a fuel supply off for the heater--You will set the bloody thing on fire. (The line pressure is around 65 psi. )
If you don't have an aux tap on the fuel pump tank cartridge then you must install a 3mm stand pipe into the cartridge --DO Not REPEAT NOT puncture the tank carcass to install a stand pipe.
In also see on the pictures then Glemo hose clamps not fully tightened. This is a Webasto FAIL trade test !`So too is failure to push fully home the clear plastic hose into the connection hose stubs.|
Dennis
Webasto certified installer
 

ranchworld

'06 158 2500 Passenger
jareddavidj you said "My van has an aux heater onboard".

If you have a factory installed Espar heater for warming your engine, mounted up behind the left headlamp you can tap into that fuel line. Not your main fuel line. That is what the photos in eagle2232's post are showing. The second from the last photo shows two Espar fuel pumps, the one on the left is the original aux heater pump and the shiny new one on the right is for the Espar D2 air heater. The photo's location is just in front of the fuel tank. Crawl under there and look for your existing factory Espar pump. Google around on "Espar install T1N" and you will see what other people have done with the D2. The Webasto is not as common...
 
jareddavidj you said "My van has an aux heater onboard".

If you have a factory installed Espar heater for warming your engine, mounted up behind the left headlamp you can tap into that fuel line. Not your main fuel line. That is what the photos in eagle2232's post are showing. The second from the last photo shows two Espar fuel pumps, the one on the left is the original aux heater pump and the shiny new one on the right is for the Espar D2 air heater. The photo's location is just in front of the fuel tank. Crawl under there and look for your existing factory Espar pump. Google around on "Espar install T1N" and you will see what other people have done with the D2. The Webasto is not as common...
I see that now, thank you. It looks like right out of the pump it drops down to a smaller fuel line. Do you cut the thicker fuel line in the middle then add the T in between that and fasten it all back up?
 

YoungRovers

New member
What you are writing scares me.
On any Sprinter with a pressurized fuel system you cannot tap a fuel supply off for the heater--You will set the bloody thing on fire. (The line pressure is around 65 psi. )
If you don't have an aux tap on the fuel pump tank cartridge then you must install a 3mm stand pipe into the cartridge --DO Not REPEAT NOT puncture the tank carcass to install a stand pipe.
In also see on the pictures then Glemo hose clamps not fully tightened. This is a Webasto FAIL trade test !`So too is failure to push fully home the clear plastic hose into the connection hose stubs.|
Dennis
Webasto certified installer
I was stating that it can’t be installed into the fuel line supply or return... as far as installing a standpipe into the tank correct me if I’m wrong but that is the only thing you can do to get a non pressurized feed, it’s the same thing the factory does for their pickup for the espar (which mine didn’t have either)... the standpipe installed into the tank is sealed above and below with Vito’s seals and then also sealed over with 5200 sealant.i have filled the tank and zero leaks..
 

ranchworld

'06 158 2500 Passenger
I see that now, thank you. It looks like right out of the pump it drops down to a smaller fuel line. Do you cut the thicker fuel line in the middle then add the T in between that and fasten it all back up?
Yes. The "T" goes in the aux heater fuel line BEFORE the aux heater pump. You are drawing fuel from the same factory standpipe as the aux heater.
 

lindenengineering

Well-known member
I was stating that it can’t be installed into the fuel line supply or return... as far as installing a standpipe into the tank correct me if I’m wrong but that is the only thing you can do to get a non pressurized feed, it’s the same thing the factory does for their pickup for the espar (which mine didn’t have either)... the standpipe installed into the tank is sealed above and below with Vito’s seals and then also sealed over with 5200 sealant.i have filled the tank and zero leaks..
Caution !
If you puncture the tank it will eventually split and start to lose fuel. The tank carcass was never designed to be punctured as it raise stresses in the tank wall.
I have had to attend to several "mistakes" such as this by DIY'rs not following trade procedures .
In extreme cases this can easily cause an accident with fuel loses on corners and roundabouts causing loss of control by other road users such as motorcyclists. I know of one motorcyclist who is suing a Sprinter owner for this very delicto! On petrol (gasoline) applications it can be worse you can set the vehicle on fire with possible fatal injuries !

The stand pipe which is often supplied in generic kits is for a class 8 truck condo cabs and bunk heater applications. The flange section is designed for metal tank applications NOT ABS style plastic tanks as in the Sprinter.

In these situations the trade instruction are clear! You drill the top plate of the fuel pump cartridge and insert a 3 mm stand pipe to accommodate the required fuel feed requirement.
If you don't adhere to these requirement you fail the Webasto trade test & certification and you obviously place people at potential un-necessary risk!
Dennis
Certified Factrory Webasto Installer
 

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