Hot water tanks.....

Capt jgw · Apr 18, 2017

Depends a lot on how it's plumbed. There should be two ports on the thermostat housing where the WH is supposed to connect. Makes it work like the heater in a car, water starts getting hot right away. Hook it up anywhere else and it can take forever to not at all.

Stu Jackson · Apr 18, 2017

NYSail said:
is there an in and out that has to be followed... out a certain port at thermostat in a certain port in hw heater then back??

No, the heater doesn't care. I checked on this when I replaced my heater hoses years ago. http://c34.org/bbs/index.php/topic,3769.0.html it's four pages with photos

The reason it's taking so long is that you have almost twice the amount of water to heat: 11 gallons instead of six.

My six gallon heater takes almost a half an hour to heat at cruising engine speed. And when first started and cold the engine takes five to ten minutes to even come up to operating temperature.

The Seaward is a good economical heater. Cheaper is a Kuuma but really crap, but looks alike. Raritan is more expensive but built the same, so not worth it compared to a Seaward (I replaced our Seaward with another one, they last from 8 - 12 years based on our C34 skippers' experiences). Isotherm is top of the line, worth every penny, comes with a thermostatic mixing valve and is wonderfully insulated. Difficulty is that the shape is different and may not fit where your Seaward is located.

Peggie Hall HeadMistress · Apr 18, 2017

Simple solution MIGHT be...turn on the water heater at the dock as soon as you arrive to let AC power heat the water--or at least give it good head start--while you're doing all you need to do to get ready to cast off. Then let the engine finish the job or keep it hot while you're away.

I disagree with Stu that a Raritan isn't worth the extra cost...they last upwards of 20 years (the one on my last boat was 26 yrs old and still going strong when I sold the boat), compared to 8-10 years that Seward and less expensive water heaters do because they have glass lined tanks and polymer shells, so unlike less expensive water heaters, they have replaceable anodes and don't rust.

John Nantz · Apr 19, 2017

The engine has a thermostat and it won't open until the engine reaches a certain temperature, ergo, [depending on how the heater hoses are plumbed] no hot water will reach it until it opens. On our boat the thermostat must open first.

I second Peggie's comment as this is what I often do:
"Simple solution MIGHT be...turn on the water heater at the dock as soon as you arrive to let AC power heat the water--or at least give it good head start--while you're doing all you need to do to get ready to cast off. Then let the engine finish the job or keep it hot while you're away."

SG · Apr 19, 2017

You may have to burp the heat exchanger line. If you have an air bubble in it, it will interfere with the flow.

There are some diverter valves that are adjustable, but usually it's a tap that runs some of the antifreeze (assuming you don't have a raw water cooled engine) through a supplemental loop.
Sometimes there is a valve on the supply to the water heater that will allow you bleed the system (or it may be have been closed by "mistake").

Ron20324 · Apr 19, 2017

FWIW, I now see on my Attwood 6 manual, one of the water connection IS specified as in, and one as out. Out, the hot one, is next to the pressure valve and thermostat, which stands to reason.

SG · Apr 19, 2017

Who services you motor in Annapolis, Ron?