Coolant Flush

[Saribbean]

Hello,
Im a new owner of the catalina 34. And never have had a heat exchanger.  Sorry if this seems really basic question...  Anyways I have done a coolant flush. To get the old coolant out of the hose that runs through the hot water heater, I connected a garden hose and flushed the coolant with fresh water.  Now I would like to flush that fresh water out, before I add the coolant and "burp" the air out of the system.  Is it easiest to get the water out when I bleed the air?  I have read how to bleed the system on the forum.  Still kind of confused. 
Thanks! 

[Stu Jackson]

If it's just fresh (NOT distilled) water, disconnect one of the hoses from the heater and let it drain into the bilge.  Use only distilled water or premixed coolant.

[Saribbean]

Hi Stu,
Thanks for the quick response.  I have looked at the hot water heater and cant fine where I could disconnect the hose. To me it looks like one continuous hose attached up at the thermostate.  Any suggestions?

Thanks
Mike

[Andrew Harvey]

Mike,
Not sure of which model of engine you have, but on my old MX25 there was a petcock on top of the thermostat housing.
Once you have refilled the coolant, run the engine with the valve open until the bubbles stop and only liquid is coming out.
Unless you have a coolant reservoir, the T stat housing is the highest part of the engine.
Andrew

[Stu Jackson]

Hi Stu,
Thanks for the quick response.  I have looked at the hot water heater and cant fine where I could disconnect the hose. To me it looks like one continuous hose attached up at the thermostate.  Any suggestions?

The hoses from the engine come to the heater.  There are two of them.  Disconnect them at the heater.  They are either at the front or the back of the heater, down low. 

[Saribbean]

Hi Andrew,
Thanks for the response. Ya ,I have the M35B with a coolant reservoir. Any tips on how to drain the coolant/ water from the water heater hoses.?  Flushed old coolant out with a garden hose. Now I need to get that water out of those hoses.  Couldn't find any hose connections on the hot water heater itself.  
Thanks

[Ken Juul]

There probably isn't much more than a pint of water in the hot water loop.  It will not seriously dilute the coolant in the engine.  But if you must get it out, disconnect both lines at the engine and use compressed air or dingy pump to blow it out.

[Stu Jackson]

Ken's solution is much easier - different end of same hose.  Doh...

[Ron Hill]

Guys : From the hull # - The engine in question is an early M35BC.

I always used some distilled water to flush and dilute the 100% coolant down to 50% mixture (extended life!). 
I have a old freezer and when we defrost it, I collect the water for such things that need distilled H2O.

A thought

[Saribbean]

Thanks for all your help. Will try blowing it out!