De-winterizing Mercruiser 5.0 mpi with heat exchange

[ZafSC]

Hi Folks,
I have a Stingray 2006 Mercruiser 5.0 Mpi inboard stern drive. I got it winterized last december, now it is time to de-winterize.
During winterize, I gave it to a marine shop for engine anti-freeze fill up, and it was done. For the fresh water, I put the antifreeze into the fresh water tank myself and circulated it thru sink, shower and waste water by running the macerator, and watched the antifreeze coming out the waste discharge hole.
Then I noticed that heat exchanger that I have the pictures attached. Looking online, there seemed to be a chance of some water left in the heat exchange. (I don't know why the water in the heat exchange did not come out when I discharged the fresh water). Anyway, I found some suggestions on the web and was able to discharge all the pressurized clean water from the heat exchange tank, until nothing left (I use the drain valve and some switch called P&T). I didn't put any anti freeze in the heat exchanger, since it was all empty and maybe it could be bad for it.
Now is the time for de-winterizing. So I think I should do the following:
1- Put the muffs and the water hose on the stern engine, turn the engine on, and keep it running a minute or two until antifreeze in the engine is replaced by hose water.
2- Put fresh water into the fresh water tank, circulate with macerator and watch clean water coming out of waste water hole.
3- Heat exchange: Do I need to do anything? Do I need to fill it with water? (Don't know how to do, if that is necessary). Or just leave it alone, it will fill it by itself with the water it takes from the muffs?
Thanks in advance

 

[Bt Doctur]

That is called the "water heater" it supplied heated water thru the AF side of the motor
1- Put the muffs and the water hose on the stern engine, turn the engine on, and keep it running a minute or two until antifreeze in the engine is replaced by hose water.
You flushed the raw water side of the heat exchanger

2- Put fresh water into the fresh water tank, circulate with macerator and watch clean water coming out of waste water hole.
Now that confusing. the macerator grinds up poop?

3- Heat exchange: Do I need to do anything? Do I need to fill it with water? (Don't know how to do, if that is necessary). Or just leave it alone, it will fill it by itself with the water it takes from the muffs?
Thanks in advance

Heat exchanger is connected directly to the motor Has AF on the engine side and raw water on the raw water side

 

[dubs283]

Can't tell from the pictures posted #1 if the water heater is plumbed for a "preheater" or heater core for engine coolant to heat the freshwater in the water heater tank

If the water heater is plumbed so as described above hopefully the winterize included a flush of that accessory portion of the engine cooling system

If there is no preheater in the water heater assy or it isn't plumbed from the engine based on your description you ought to be able to charge the freshwater system by filling the tank with potable water and turning on the pump with a faucet open. Normal operation system will purge air until the tank fills enough to prime the pump. Then freshwater should appear shortly thereafter. Continue with each faucet control hot/cold until the entire system is operational with the pump holding pressure

 

[ZafSC]

That is called the "water heater" it supplied heated water thru the AF side of the motor
1- Put the muffs and the water hose on the stern engine, turn the engine on, and keep it running a minute or two until antifreeze in the engine is replaced by hose water.
You flushed the raw water side of the heat exchanger

2- Put fresh water into the fresh water tank, circulate with macerator and watch clean water coming out of waste water hole.
Now that confusing. the macerator grinds up poop?

3- Heat exchange: Do I need to do anything? Do I need to fill it with water? (Don't know how to do, if that is necessary). Or just leave it alone, it will fill it by itself with the water it takes from the muffs?
Thanks in advance

Heat exchanger is connected directly to the motor Has AF on the engine side and raw water on the raw water side

1) Ok I see. It is clearing up a bit. There is both engine water (antifreeze now) and raw water in the heat exchanger. Now I flushed (emptied) the raw water. So, how do I fill the raw water in the heat exchanger?
2) Macerator grinds and at the same time empties/flushes the waste water tank to outside the boat. Since all the fresh water (which is antifreeze now) in the faucet goes to sink , and that goes to to waste tank, I open all the faucets and the macerator together time to flush all the antifreeze in the fresh water system.
3) So filling the fresh water tank will automatically fill the heat exchange raw water? (The AF side will be taken care of by engine flushing)

 

[dubs283]

I think you are referring to fresh water, e.g.what comes out of the faucets in galley/head as raw water

Raw water is water that is pumped on-board using the surrounding water (lake, river, ocean, etc) the boat is floating in. Engines use raw water for the cooling systems and some pumps are used for raw water wash downs, livewells, etc.

Fresh water is added to and stored in a dedicated on board tank via a deck fill/lid usually located on one of the gunwhales. Sometimes their hidden under hatches elsewhere. The fresh water system should be independent of all other on board water systems

Grey water is waste water from faucets/sprayers that is either discarded directly overboard or drained into an on board holding tank for removal later. Some systems have a macerator pump to exit grey water overboard, others have deck lids that use a separate vacuum removal device for emptying

Black water is human waste water from the toilet system that drains into an on board holding tank that has similar evacuation methods to the grey water tank

The water heater pictured post #1 is part of the fresh water system. The only caveat is it may or may not utilize a "preheater" system I explained in post #3

 

[ZafSC]

I dewinterized the engine coolant with (raw water I guess) by placing the muffs with hose water and running the engine a few minutes, I observed the red cooler became normal water coming out of the exhaust.
I also emptied the red coolant in fresh water tank, by opening all faucets, then I filled it fresh water.
Now the question is, should I do anything with the water heater using the drain tap on my #1 posting? I connected a black hose to it (see picture) but didn't observe any water coming out. Is it already filled fresh water? How do I know if there is enough water in it. Should I fill it with fresh water using the drain tap?
Thanks

 

[dubs283]

With the fresh water system tank full and the fresh water pump turned on the water heater will fill via the cold/blue fresh water line attached to the water heater. Opening a hot faucet, preferably the furthest one away from the water heater will allow the water heater to purge the air inside it out through the faucet while it fills with water

Once you get a steady flow of water from the hot side of the faucet, continue opening hot faucets throughout the system until fully purged/flowing steady water. Continue with the cold side of all faucets until fully charged. With the fresh water pump still on and all faucets closed the fresh water pump will pressurize the system until the pressure switch on the pump engages and turns off the pump automatically. If the pump continues to run there is a leak somewhere or the pump does not have a pressure switch

If the pump runs continuously and no water is present at any faucet the in line filter for the pump may be clogged and needing cleaned out