Type 2 Water Heater Connection

with

Water Heater By Pass Valve

Piping consists of a 3/4" valve, two TEE's, and an elbow along with some reducers and barbs for the hoses.  Chris used a Ball valve as it makes it a lot easier to tell what the position of the valve is.  Chris also said that brass fittings look neater.  Raritan recommends this method but cautions you to do what the engine manufacturer recommends. Click here for Raritans installation recommendations then see Fig 4 near end of document.

The above diagram is originally from Catalina30.com, but modified to show series connection to a water heater in blue and the optional by pass valve in turquoise.. Thermostat by pass hose was added.  

Click here to return to schematic diagrams of the different types of water heater hook ups

This page was created October 24, 2002

This page was last updated on: January 4, 2017

Chris Albertson a Catalina 36 owner posted the following

well written summary on the cal-list@sailnet.net on Oct 14, 02:

Short story: With the water heater removed the engine will

stay exactly at the thermostat setting even at full throttle.

After I changed to a larger prop, my M25 engine became cooling

limited. That is I had to reduce the RPM's or the engine would

eventually (after about an hour) over heat. With the old 15x11

fixed prop I did not have a cooling problem but with the 16x11

folding prop I do.

Easy fix. I opened the heater by-pass valve. I have a 160F

thermostat installed and with the bypass valve open the engine

will not heat above 160 even at 90% throttle for an hour.

I was able to do a pretty conclusive test as I had to motor in

dead calm at 8:00am to a race start.

What this proves to me is that having a water heater plumbed

in line with the engine coolant greatly reduces the engine's cooling

ability by slowing the coolant flow through the engine and the

heat exchanger. With the bypass valve I can switch the water

heater in and out of the loop in a second by turning a 3/4" ball valve

handle and can see the effect quickly

Chris Albertson

Home: 310-376-1029 chrisalbertson90278@yahoo.com

Cell: 310-990-7550

Office: 310-336-5189 Christopher.J.Albertson@aero.org

Below is a picture of a water heater by pass valve implement with

pipe fittings.