Which is heater inlet?

[jesutton3]

I have one of the Y adapters here from Heater Craft and I am planning on installing it this weekend. Without running the boat and feeling to see which hose is warmer how do I know which is the supply and which is the return line?

I know it goes in the fresh water line before the raw water pump with the return line connected to it. I'm just not sure which is the supply and return line.

Just to note both lines are connected to the engine currently. One up near the air intake and I can't remember for the other.

[bcoppess23]

Unless the heater core has a special marking telling which is the in and which is the out, it should not matter. Hope this helps

[BuFootin]

Unless the heater core has a special marking telling which is the in and which is the out, it should not matter. Hope this helps

yep, what he said. There is not necessarily a inlet / outlet to the heater core.

[CedarLakeSkier]

I have one of the Y adapters here from Heater Craft and I am planning on installing it this weekend. Without running the boat and feeling to see which hose is warmer how do I know which is the supply and which is the return line?

I know it goes in the fresh water line before the raw water pump with the return line connected to it. I'm just not sure which is the supply and return line.

Just to note both lines are connected to the engine currently. One up near the air intake and I can't remember for the other.

The above answers are correct for the heater core. If you are looking to install the "Y" adapter and the lines are already in place without the "Y" adapter, the hose coming from the top of the manifold near the spark arrestor is the "supply" of hot water. The other hose is the return (meaning the one you want to connect to the "Y")

[jesutton3]

The above answers are correct for the heater core. If you are looking to install the "Y" adapter and the lines are already in place without the "Y" adapter, the hose coming from the top of the manifold near the spark arrestor is the "supply" of hot water. The other hose is the return (meaning the one you want to connect to the "Y")

Thanks. That was the info I was looking for. The heater is already in place from the factory but installed before the Y fix was released.

[NorCaliBu]

Just to note both lines are connected to the engine currently. One up near the air intake and I can't remember for the other.

If the return line is in fact connected at the engine block (HeaterCraft aftermarket instructions call for the return line to be connected at the engine mounted circulation pump) then now is the time to move the return line to the raw water intake hose so that the raw water pump is pulling the water through the core. The engine circulation pump doesn't create much suction and thereby doesn't pull much hot water through the heater core causing your heat output to be lame at best. Graft that "Y" pipe into your raw water intake hose right in front of the raw water pump.

Edited March 20, 2011 by NorCaliBu

[jesutton3]

If the return line is in fact connected at the engine block (HeaterCraft aftermarket instructions call for the return line to be connected at the engine mounted circulation pump) then now is the time to move the return line to the raw water intake hose so that the raw water pump is pulling the water through the core. The engine circulation pump doesn't create much suction and thereby doesn't pull much hot water through the heater core causing your heat output to be lame at best. Graft that "Y" pipe into your engine feed hose right in front of the raw water pump.

Yeah after attempting this mod the return line was hooked to the engine water pump. The key word here is attempt since Heatercraft sent me hose clamps that are too small or the raw water hose.

I went to the store earlier in the day to get a plug for the hole left in the engine water pump after removing the heater hose. I didn't check the Heatercraft supplied hose clamps since I figured they are familiar with inboard engines. Since everything was closed when I found this out I guess I'll wrap it up tomorrow.

[Hentz]

Just to verify...The Y adapter gets placed in line with the raw water pick up line. The heater return hose gets connected to the small pipe on the y. The part I am fuzzy about is---Does the "to heater" hose on top of the engine stay in place?

Thanks a lot

[NorCaliBu]

Just to verify...The Y adapter gets placed in line with the raw water pick up line.

The heater return hose gets connected to the small pipe on the y.

The part I am fuzzy about is---Does the "to heater" hose on top of the engine stay in place?