Hello there!
We re trying to get the domestic hot water heater hooked up to the 307Q engine and can't get it to work. Does anyone know where you hookup the hot water lines to the engine? Thanks!

Hello Christine,

Just a guestion first, and that is, "is your motor a standard or closed cooling system".
The standard system takes water from under the hull and runs it directly through the motor and out the exhaust. The closed system uses a heat exchanger, and there is antifreze inside the motor block with that system.

Tom

it is a closed system (freshwater cooled)

In that case I would take one of the output lines from the heat exchanger where it is going to dump into the exhaust pipe, that would appear to be the safest line to tap into, assuming you are talking about a flow through heat exchanger type of a hot water heater. Run the line through the heater, and hook it up to where it was going to discharge, all should be well.

Tom

This might help the discussion I see going on now!

Here is a photo of the standard Q, it's not the closed system, but thought it would be worth something.






Here are the cooling diagrams from our files, showing the various systems on the Q motors.





Hope this helps,.

Paul

On the top diagram, that hose at the very upper left hand side, see where the discharge line at the heat exchanger is, going from the top of the heat exchanger directly to the riser. That is where I would cut the line, run it to the HWH and then right back to the heat exchanger. That would appear to be the least critical hot water source.

Anyone else got any ideas? I have never hooked up a hot water heater that uses a heat exchanger mode like this one, but I'm sure it would deliver plenty hot water after running a while.

Tom

where do you hook in the hoses from the hot water heater to the fresh water cooling system on teh 307Q engine. Where do we make ther physical hook ups to the engine?

Hi Tom,
It's actually my Dad's boat and for some reason he can't respond on this website. Is there some way he could contact you direct? My email is gollum33@aol.com. Thanks!
Christine

Hi Christine, and "WELCOME ABOARD" to you and your dad. Regarding your note, what kind of a message is he getting when he tries to post here? You can email me directly at chriscraftcommander@hotmail.com and I'll help you guys get it working.

Regards,

Paul
forum moderator

Had good luck pulling hot coolant, (on a 350K) from the top outlet of the coolant circulation pump. Run a hose to the WH and a return hose to the thermostat housing...as the orig. hose was run.

I get VERY HOT water in about 15 min. after warm up. The one problem is regulating the high temp water as it leaves the heater...The shower can get a bit too toasty in unexpected spurts!