Multiple fuel draws with one stand pipe?

[Paddy]

I have a sprinter with a factory webasto hydronic engine warmer which I plan to hack into a water heater for camping and hot tubbing, but I am also considering a diesel air heater for the cabin. If possible I'd like to just T into the existing webasto fuel line for the air heater but I'm concerned that it may suck air from the hydronic and ruin the prime of that guy rather than sucking fresh fuel. Anyone try this?

 

[naterry]

I'm not a webasto expert but I think it would be safe to assume that it has an internal check valve. Either way if it has the check valve you're fine, and if it doesn't then it's designed to self prime every time. Also consider that gravity could naturally pull fuel away from the heater and the engineers had to design around that.

 

[Paddy]

That's what I was thinking too. They do self prime but you don't want to drain the pipe because it can take many attempts on a new setup to get primed. I guess I'll try it and find out. Thanks.