[FONT=Times New Roman][FONT=Times New Roman][FONT=Arial]Typically the antifreeze does not have an obnoxious smell as you describe. The problem may be other nasties living in your system. Below is a possible remedy I used with success.[/FONT][/FONT][/FONT]
[FONT=Arial]-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------[/FONT]
[B][FONT=Times New Roman][FONT=Times New Roman][FONT=Arial]Water System Smell, or Sulfer Smell from Hot Water Tank. [/FONT][/FONT][/FONT][/B]
[FONT=Times New Roman][FONT=Times New Roman][FONT=Arial]If you have a Sulfur (rotten egg) smell from the hot water side of your water system, or a stinky smell from your water tanks, then it is time to bleach the system. [/FONT][/FONT][/FONT][FONT=Times New Roman][FONT=Times New Roman][FONT=Arial]Start by emptying one of the boat water tanks. With the second tank closed and the open tank empty, no more water will flow from the faucets. [/FONT][/FONT][/FONT][FONT=Times New Roman][FONT=Times New Roman][FONT=Arial]At this point it must be noted that the hot water tank still is full with approx. five gallons of smelly water.[/FONT][/FONT][/FONT]

[LEFT][FONT=Times New Roman][FONT=Times New Roman][FONT=Arial]Add about two or three gallons of water to the empty water tank. You need to put in enough to get the system pumping again. Now add a gallon [/FONT][FONT=Arial]of straight off the shelf BLEACH to the water tank.[/FONT][/FONT][/FONT]
[FONT=Times New Roman]
[FONT=Times New Roman][FONT=Arial]Next we must fill the system with this bleach water. Turn on the hot water faucet in the galley and let at least a gallon of water run out. This adds a gallon of bleach water to the water heater. If a strong smell of bleach is not coming out of the faucet yet then let it run longer. Now turn on the galley cold water till you smell the bleach in the water. (This should not take long). Do the same for the hot and cold at the head sink. This will clean the pipes while you are doing the hot water heater.[/FONT][/FONT]

[FONT=Times New Roman][FONT=Arial]Let this mixture sit in the system overnight. Drain the system of the bleach water and refill with five gallons of water and drain again. Fill water [/FONT][FONT=Arial]tank and your odor should be gone. If you add a cup of this bleach at reach fill-up of the water tank, you should not have any smell in the system other than the faint bleach smell that you would normally get in a city water system.[/FONT][/FONT]
[FONT=Times New Roman][FONT=Arial]If this did not solve your egg smell that it is time to pull the 110v -heating rod on the water heater and replace it. That is a last resort. If you plug into shore power while away from the boat, it is not a good practice to leave the hot water switch turned on. This will add to the smell problem as well as safety hazards. Try turning on the 110v heater switch just as you arrive at the boat and let it heat the water while you are preparing the boat for your sail. Turn the heater off and disconnect the shore power the last thing before you sail. This will let you start out with some preheated water and the engine will do the rest. [/FONT][/FONT][/FONT][/LEFT]

[LEFT][FONT=Verdana]1. Prepare a chlorine solution using one gallon of water and 1/2 cup (4[/FONT][FONT=Verdana]oz) Clorox or Purex household bleach (5% sodium Hypochlorite [/FONT][FONT=Verdana]solution ). With tank empty, pour chlorine solution into tank. Use one [/FONT][FONT=Verdana]gallon of solution for each 5 gallons of tank capacity.[/FONT][/LEFT]

[LEFT][FONT=Verdana]2. Complete filling of tank with fresh water. Open each faucet and [/FONT][FONT=Verdana]drain cock until air has been released and the entire system is filled. [/FONT][FONT=Verdana]Do not turn off the pump; it must remain on to keep the system [/FONT][FONT=Verdana]pressurized and the solution in the lines.[/FONT][/LEFT]

[LEFT][FONT=Verdana]3. Allow to stand for at least three hours, but no longer than 24 hours.[/FONT][/LEFT]

[LEFT][FONT=Verdana]4. Drain through every faucet on the boat (and if you haven't done this [/FONT][FONT=Verdana]in a while, it's a good idea to remove any diffusion screens from the [/FONT][FONT=Verdana]faucets, because that is what's likely to come out will clog them). Fill the tank [/FONT][FONT=Verdana]again with fresh water only, drain again through every faucet on the [/FONT][FONT=Verdana]boat.[/FONT][/LEFT]

[LEFT][FONT=Verdana][FONT=Verdana]5. To remove excess chlorine taste or odor which might remain, [/FONT][/FONT][FONT=Verdana][FONT=Verdana]prepare a solution of one quart white vinegar to five gallons water and [/FONT][FONT=Verdana]allow this solution to agitate in tank for several days by vehicle [/FONT][FONT=Verdana]motion.[/FONT][/FONT][/LEFT]

[LEFT][FONT=Verdana][FONT=Verdana]6. Drain tank again through every faucet, and flush the lines again by [/FONT][FONT=Verdana]fill the tank 1/4-1/2 full and again flushing with potable water.[/FONT][/FONT][FONT=Verdana][/LEFT]
[/FONT]

Geoff, congratulations and welcome.

Resources: [url]www.sailboatowners.com[/url], Forums, Expert Forum, Head Mistress

Peggie Hall, wrote The Book on Boat Odors.

Use the search engine on that message board with the word: recommission. She's published online answers to your specific question.

If you can't find it, come back here and I'll do some copying for you.