Diesel Heater, fed from CAV filter - best practice for gravity fed Yanmar 2GM?

[frlrubett]

Have been reading a few of the opinions on plumbing a diesel heater directly into the CAV filter. My old boat had this setup (installed by Autoterm engineer) and ran flawlessly for years but this boat's fuel is gravity fed.

This is the setup I have currently,

- Diesel Heater, with 5mm ID fuel pipe
- Yanmar 2GM gravity fed
- CAV filter, 1/2 inch UNC

Is it wise to install a tap so I can isolate the fuel feed to the heater? (link to the part would be great also)

Is a non return valve necessary? (link to the part would be great also)

I have found this, but would have to stretch the fuel line out a bit.. HERE. Would this work?


Anything I am missing, please let me know! Thanks!

 

[Ian_Edwards]

Assuming the diesel heater has a metering pump, and the diesel line doesn't have any heigh points which can trap air. It should work, the ticker pump will lift the diesel, my experience, about 1m.
Connecting to the second output on the CAV filter should be straight forward, you'd need a 1/2" UNC male to 5mm ID spigot connector and hose clamps.
I don't think you need a non return valve.
But a small ball valve to isolate the heater is a good idea. You could fit that at the CAV filter or inline.
I'd talk to some one at ASAP supplies, they'll be able advise and supply the parts.

 

[Sandy]

Does your tank have a second point to extract diesel from? If it does then plug your fuel line onto that and lead it to the pump.

There are lots of YouTube videos about how to install them and lots of eBay sellers who will supply all sorts of exciting plumbing.

 

[samfieldhouse]

This is literally my exact setup; Yanmar 2GM20 and an Autoterm 2D both fed from a CAV filter.
Tap on both and non return valve on heater feed.

HOWEVER even with a non return valve fitted in line before the heater fuel pump, the heater will not run with the engine running.

You may have read other posts from me on this. I don’t understand the physics, but for whatever reason is just won’t work. I have to turn the fuel tap for the heater line off at the CAV filter before starting the engine otherwise I have to manually prime the heater pump.

I’d assumed that both running together would just pull more through from the tank, but apparently not.

Apparently Eber suggest separate fuel lines.

For now, I don’t mind because the boat heats up so fast there’s no reason to run the heater and the engine at the same time. The only advantage I can see would be to cover the initial amperage pull, but that only lasts a couple of minutes. The 2D pulls about 0.8a when running.

 

[Plum]

Have been reading a few of the opinions on plumbing a diesel heater directly into the CAV filter. My old boat had this setup (installed by Autoterm engineer) and ran flawlessly for years but this boat's fuel is gravity fed.

This is the setup I have currently,

- Diesel Heater, with 5mm ID fuel pipe
- Yanmar 2GM gravity fed
- CAV filter, 1/2 inch UNC

Is it wise to install a tap so I can isolate the fuel feed to the heater? (link to the part would be great also)

Is a non return valve necessary? (link to the part would be great also)

I have found this, but would have to stretch the fuel line out a bit.. HERE. Would this work?


Anything I am missing, please let me know! Thanks!

When i fitted my Eberspacher the instructions said "The fuel must not be conveyed by gravity or
overpressure in the fuel tank."