Water heater.... does size matter?

Rich Stidger · Oct 17, 2017

We have a 6 gallon Seaward and have never run out of hot water for 2-3 showers if we start with a full tank. I figure that a shower uses 5 gallons per person, but given the high temperature of the hot water, most of the shower water is mixed with cold.

Ken Cross · Oct 17, 2017

We don't normally shower in the boat, but we have and the 5 gallon water heater has never run out of hot water.

Ken

pateco · Oct 17, 2017

When my HW heater died a couple of years ago and started leaking, I thought about replacing it, and then realized I never used it. A hot shower on a hot, humid un-airconditioned boat just never felt right. I bypassed and disconnected the heater completely. I will remove it just as soon as I find the time to get into the lazarette with a sawzalll to cut it into pieces that will fit through the opening.

Stu Jackson · Oct 17, 2017

I replaced our 6 gallon Seaward in 2013 after the PO replaced the original one in 1998 (1986 boat). I agree with Rich, wouldn't be without it. Plenty of HW. Don't know how much extra storage you'd get with a slightly smaller footprint and height, though. Good luck, it's a purely personal decision. Our shower wand has a shutoff button valve, saves a lot of water and keeps the temperature the same on or off.

Terry Cox · Oct 17, 2017

Our six gallon Seward has served us well over the years, even during our extended two month cruises each season. I'm accustomed to taking a navy shower whether on the boat or at home. Usually use about three gallons for my shower.

Capt jgw · Oct 17, 2017

Larger heater just takes longer to heat. If you're conserving water at all it would be really hard to use up 11 gallons of hot water with one or two showers plus dish washing. 6 gallons is plenty. One boat I had was only two gallons, and we got by ok on that.

Rick486 · Oct 17, 2017

NYSail said:
well of course size matters, however with the hot water heater I am beginning to rethink in my case. I have a 12 year Old seaward 11 gallon. Does the job when plugged in and after Long runs. However we find ourselves more typically using solar showers..... and if the water is not right just adding a kettle of hot water and all is good. For us it makes more sense..... we have a hatch in shower put bag above and run hose down. All good and no need to turn on engine or generator. We have used in boat shower a few times but mostly when on the dock and at those times I use water sparingly by wetting down soaping up
And rinsing off. Can easily take a good shower with a couple gallons. 4 gallons (shower bag) and I feel like a king (on boat.... at home I probably average 15 -20 minute showers).
Anyway was considering when the time comes to replace my current hw heater with a 6 gallon and gain some storage. What is the general consensus. Thanks!

2 Gal! To me, that is extravagant. When we are cruising I take a great shower with 2 quarts!!! 2 Gal is what I was taught is a "Hollywood shower". 2 quarts is a "Navy shower".

uncledom · Oct 17, 2017

Extravagance is heating hot water. I only heat cold water. I just have a water heater not a hot water heater.

Capt jgw · Oct 17, 2017

Yeah, it bugs me too when people say "hot water heater" . Label on the box just says "Water Heater".

Allan12210 · Oct 17, 2017

Since these water heaters are displacement type, as soon as you start to draw from them, the water used is replaced with cold and it quickly drops the temperature with what is left. I installed a thermal mixing valve outside my Seaward (now 33 years old) so most of the dilution is there. By running the internal temperature as high as possible, it has in effect acted like a larger water tank. So, possibly a 6 gallon replacement can feel like an 11 gallon tank without the mixing valve. Either way, the thermal mixing valve is a great safety addition if you don't have one.

https://www.amazon.com/gp/product/B00SYC1IV6/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Bill Roosa · Oct 17, 2017

Actually Allan the hot water is drawn off the top of the tank and the cold water enters the bottom so the actual water coming out of the tank is pretty much the same temp as at the start until the tank is almost full of cold water. Now if you are taking two showers and washing dishes at the same time you might get enough flow to mix the cold and hot water in the tank but I'm thinking even then you would just have really low water pressure for all concerned.
FWIW

Gene S · Oct 17, 2017

I'm not one to brag but..... Oh yeah, water heaters. I have a 5 or 6 gal one and have no problems as long as I take navy showers. Rinse and lather, repeat. It only takes about 15 min running the engine to heat the water. My Quick boiler holds heat a while.

SG · Oct 17, 2017

I had a buddy who controlled the showers by turning off the pressure water. When the accumulator tank was "used-up", the pressure died, and the shower was over.

Until he got married to his second wife, that system worked. Thereafter, his system was scraped. ;^)))

bawlmer · Oct 17, 2017

6 gallon seaward water heater works great. I can take a 5 minute shower and still have hot water left. This is from engine heated water. Actually I have never run out of hot water but I have never deliberately tried to.

Ron20324 · Oct 30, 2017

Allan12210 said:
. . Either way, the thermal mixing valve is a great safety addition if you don't have one.
https://www.amazon.com/gp/product/B00SYC1IV6/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Allan, is that link the one you got? I got one, and am not sure what the actual threads are. Where did you get which fittings?

centerline · Oct 31, 2017

on all of my boats that were fitted with a pressure water system, conservation was the single most important factor. large water heaters run contrary to the concept of conservation.
the water heater can be fairly small...5 gallon? or less is better in my opinion. if it is fitted with a heat exchanger you can start the motor for 10 minutes and it will heat the water to a comfortable temperature nearly as fast as it can run thru the shower head ... personally, I see no reason to have a large, heavy, expensive water heater for only two or three people... knowing what you have and how to use it, with a bit of planning and care of your shower habits, a 2 gallon water heater could be sufficient for two people.... but then if you have an unlimited supply of fresh water, go for the big heater, as then there is no real need to conserve...

Jackdaw · Oct 31, 2017

NOTHING separates yachting from boat camping more then a hot shower belowdecks.

capta · Oct 31, 2017

Once we had the water maker the two gallon showers went out the window, as did their rarity. After a lifetime of water rationing (one trip was 60 US gallons for 3 people to cross the Atlantic) it is so nice to have a loooooooong hooooooooot shower, any time, even while sailing.
We have an 11 gallon water heater and it really is worth the added expense, IMO.

capta · Oct 31, 2017

Once we had the water maker the two gallon showers went out the window, as did their rarity. After a lifetime of water rationing (one trip was 60 US gallons for 3 people to cross the Atlantic) it is so nice to have a loooooooong hooooooooot shower, any time, even while sailing.
We have an 11 gallon water heater and it really is worth the added expense, IMO.