Fluid analysis; on-demand water heaters

R

rapscallion

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Hello. New here; hoping to learn more about what to expect in the survey process.

Considering purchasing an early 80s vintage Carver 3007. Also looking at a similar age 3207. In addition to having the boat surveyed, inspected by a qualified marine mechanic, and sea trialed, I was considering having samples of the engine oil and transmission oil analyzed by a laboratory. I understand that much can be learned from fluid analysis. What about a sample from the domestic fresh water system? Has anyone had any experience with water purity issues? Also, would analysis of samples from the fuel tanks reveal anything about corrosion inside the tanks?

A second question relates to on-demand water heaters. I had a propane-powered unit in my home and it was great. It had a pilot light, though, which would concern me aboard a boat. I'm aware there are models with piezo-electric starts, but they still produce a spark. Are there ignition-protected marine-rated on-demand water heaters available on the market? What do the surveyors think of them?

Forgive me if these topics have been dealt with previously, or elsewhere on this site.

Thanks!
 
We have an electric marine rated on demand water heater.
I don't remember the brand name and I won't be home for
2 more weeks to be able to check on it.
The company makes a 20, 25 and 30 amp models.
Ours works well, but you can only run hot water when showering.
If we run cold water with it, it doesn't get hot enough.
 
You are concerned about the spark, what about the fire. If you want to go electric it takes alot of power. What rduhon is saying if you want water in the shower, it does not work well.
I have a 17 gal. electric water heater, set on 180, never runs out, 4 showers no problem.
 
I'm with Jim on this I looked into it, read what they do they raise the water temperature by 20 to 30 degrees depending on current draw/sizing. So assume 60 degree tank water with the 30amp unit you would only be 90 degrees max and that is a bit cold for my shower. I have a smaller Atwood 11 gallon unit set at 180 in my boat (all stainless) mix with cold and I can get 2 long steaming showers out of it. Now assuming you are at the dock and not on a generator the water out of the well could even be colder. They draw a full leg of power on a standard dual 30amp boats. Again I once thought they were a good idea until I checked how they operate. If you have a gas boat forget about a propane based unit unless you want to go bang. Home units are larger and draw up to 60 amps at 220VAC. I have one in my Jacuzzi it draws 45 amps and the circulation pumps run about 15 amps. I had to have a special circuit run with #6 AC wire and a dual GFCI breaker and that is 60 amps at 220Volts not 120volts you will have on most boats. Needless to say the Jacuzzi is now drained and I rarely fill it and use that room in the house. Talk about adding at least a hundred dollars a month to your house electric bill! In closing I wouldn't do it research a larger possible rectangular stainless unit its worth it.
Bill
 
I had water purity issues with a my 93 not enough to get sick just horrible taste. I replaced my aluminum water tanks with Poly/thick plastics problems solved. You can also add filters at each faucet location on the cold water side and but none on the main hot water lead or use a whole boat filter. I replaced all my faucets, tanks, 12 volt DC high volume pump, accumulator and flushed my water tubing with bleach problem solved. There are additives to keep your water bacteria free I can not use them because they will damage my water maker when it backflushes the additives will damage the membranes (big bucks repair). The water maker cycles once a week if I don't use it from the tanks the process uses 5 gallons and is automatic. If I am not going to use it it needs to be pickled with special chemicals. The water maker also has a UV system to further purify the water I make, I would say it makes water as good as any bottled water. My system is made by Spectra and runs on my house battery bank.

Bill
 
engine and trans oils can be analyzed to determine if any metal or water etc is in the oil. Folks may tell you that without any history of previous tests they aren’t much good but if there is a serious problem the tests may show it.
They are cheap insurance. Test results showing no problem don’t mean no problem but results showing a problem do mean there is a problem
 
We have no issues with water heat, if we only use the hot water side.
If we try to mix the cold with the hot, we get cool water.
We have the 25 amp unit. It works good in any ambient temps., but we
live in the south. We seldom get really cold weather and we don't
get any frozen water.
 
IMHO, a six gallon water heater with a heat exchanger will be about 1/5 the price and better in the long run. Get a heater that can be easily replaced w/o removing any engine parts. Boat manufacturers tend to build boat as if they never had to deal with their own stupidity....DAMHIK!!!!! ARGHHHH.
 
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