Hot water heater install

SilentOption · 30-03-2008, 18:46

I am putting a new HWH in my boat. Its electric and also connects to the engine. The location is an issue. I assume it has to be lower then the top of the engine. Is this correct?

never monday · 30-03-2008, 18:50

ideally yes.

**James S** · 19-11-2008, 00:55

why...I'm getting ready to install mine and, as it stands now it will be about 1 foot above the engine.

**James S** · 19-11-2008, 01:33

Is the only concern the coolent over flowing out of the thermastat when I open it.
For maintainance reasons I plan on Isolating the loop from the engine with valves.
Problems??

SilentOption · 19-11-2008, 04:39

I installed the HWH in the original location and ran the engine for an hour under load.
I moved the HWH to a location below the engine and ran the same test.

With HWH above engine the temp was 20-30 degrees higher than when the HWH was below.
I tried to fill the entire system with it up, using a separate line and a valve but it didn't work very well and yes, you can't remove the cap without making a mess. Now the engine running cooler and I can fill using the cap as designed. No valves.
The one other thing I did is install an inline temp sender at the HWH outlet.

**James S** · 19-11-2008, 04:53

Well that sucks...I do have an alternative location...but not as sweet.
What does the temp sender at the outlet do?
Thanks for the help

SilentOption · 19-11-2008, 05:06

I was planning to use it to determine exactly how hot the water gets in the HWH when using just the engine to heat the water. Then I decided to just use it as a remote engine temp sender the navstation so I can monitor the engine when not on watch.
Because I know I am the only one on the boat who watches that sort of thing religiously while underway underpower.

**James S** · 19-11-2008, 05:19

Do you see any differance in the readings?
How about when the WH is being used and is diluted with cold?

SilentOption · 19-11-2008, 06:37

I ran the hot water in my sink while running the engine and later while heating with electricity and the result was the same. The water eventually cooled significantly as the hot water was depleted leaving me with luke warm at best running water.
While the engine was running I didn't see a significant drop in the engine water temp. I suspect the gauge would have to be calibrated or marked in much smaller increments however to actually see a drop from cold water circulating through the heater.

The water in the tanks wasn't all that cold to begin with either.

**James S** · 19-11-2008, 07:00

I remember the Dashues talking about their system...to not waste water they would put a valve on the hot water supply side at the furthest point from the WH, with the water going back into the fresh water tank...when the handle gets hot they close it, and use the sink mixer knowing that the water was hot.
They said that they were actually able to use this for some time to cool the engine via the exchanger in the WH...
Thanks for all the info.

SilentOption · 19-11-2008, 07:26

I was looking at the hose run from the HWH to the forward shower (28') and I feel like a lot of heat is lost there. I am considering insulating the entire length of that hose.

**James S** · 19-11-2008, 07:47

I think you’re right.
I haven’t started yet with the hot & cold supply lines (still have to figure out what to do with the WH) but when I do, it will most probably be CPVC and definitely insulated.
Do you have any more pics of your boat?

30-03-2008, 18:46	#1
SilentOption Registered User Join Date: Jan 2006 Posts: 282	Hot water heater install I am putting a new HWH in my boat. Its electric and also connects to the engine. The location is an issue. I assume it has to be lower then the top of the engine. Is this correct? __________________ 11.21.2009 request at help desk to close acct. PW chgd, notifications removed. DOB 04.08.1960

30-03-2008, 18:50	#2
never monday Commercial Vendor Join Date: Jun 2005 Posts: 1,553	ideally yes. __________________ inlandmarinedieselathotmail

19-11-2008, 04:39	#5
SilentOption Registered User Join Date: Jan 2006 Posts: 282	I installed the HWH in the original location and ran the engine for an hour under load. I moved the HWH to a location below the engine and ran the same test. With HWH above engine the temp was 20-30 degrees higher than when the HWH was below. I tried to fill the entire system with it up, using a separate line and a valve but it didn't work very well and yes, you can't remove the cap without making a mess. Now the engine running cooler and I can fill using the cap as designed. No valves. The one other thing I did is install an inline temp sender at the HWH outlet. __________________ 11.21.2009 request at help desk to close acct. PW chgd, notifications removed. DOB 04.08.1960

19-11-2008, 05:06	#7
SilentOption Registered User Join Date: Jan 2006 Posts: 282	I was planning to use it to determine exactly how hot the water gets in the HWH when using just the engine to heat the water. Then I decided to just use it as a remote engine temp sender the navstation so I can monitor the engine when not on watch. Because I know I am the only one on the boat who watches that sort of thing religiously while underway underpower. __________________ 11.21.2009 request at help desk to close acct. PW chgd, notifications removed. DOB 04.08.1960

19-11-2008, 06:37	#9
SilentOption Registered User Join Date: Jan 2006 Posts: 282	I ran the hot water in my sink while running the engine and later while heating with electricity and the result was the same. The water eventually cooled significantly as the hot water was depleted leaving me with luke warm at best running water. While the engine was running I didn't see a significant drop in the engine water temp. I suspect the gauge would have to be calibrated or marked in much smaller increments however to actually see a drop from cold water circulating through the heater. The water in the tanks wasn't all that cold to begin with either. __________________ 11.21.2009 request at help desk to close acct. PW chgd, notifications removed. DOB 04.08.1960

19-11-2008, 00:55	#3
James S Moderator Moderator Join Date: May 2008 Location: I live in Yemen...the boats in Lebenon Boat: 1978 CT48 Arctic Lady Posts: 1,955 Images: 125	why...I'm getting ready to install mine and, as it stands now it will be about 1 foot above the engine.

19-11-2008, 01:33	#4
James S Moderator Moderator Join Date: May 2008 Location: I live in Yemen...the boats in Lebenon Boat: 1978 CT48 Arctic Lady Posts: 1,955 Images: 125	Is the only concern the coolent over flowing out of the thermastat when I open it. For maintainance reasons I plan on Isolating the loop from the engine with valves. Problems??

19-11-2008, 04:53	#6
James S Moderator Moderator Join Date: May 2008 Location: I live in Yemen...the boats in Lebenon Boat: 1978 CT48 Arctic Lady Posts: 1,955 Images: 125	Well that sucks...I do have an alternative location...but not as sweet. What does the temp sender at the outlet do? Thanks for the help

19-11-2008, 05:19	#8
James S Moderator Moderator Join Date: May 2008 Location: I live in Yemen...the boats in Lebenon Boat: 1978 CT48 Arctic Lady Posts: 1,955 Images: 125	Do you see any differance in the readings? How about when the WH is being used and is diluted with cold?

19-11-2008, 07:00	#10
James S Moderator Moderator Join Date: May 2008 Location: I live in Yemen...the boats in Lebenon Boat: 1978 CT48 Arctic Lady Posts: 1,955 Images: 125	I remember the Dashues talking about their system...to not waste water they would put a valve on the hot water supply side at the furthest point from the WH, with the water going back into the fresh water tank...when the handle gets hot they close it, and use the sink mixer knowing that the water was hot. They said that they were actually able to use this for some time to cool the engine via the exchanger in the WH... Thanks for all the info.

19-11-2008, 07:26	#11
SilentOption Registered User Join Date: Jan 2006 Posts: 282	I was looking at the hose run from the HWH to the forward shower (28') and I feel like a lot of heat is lost there. I am considering insulating the entire length of that hose. __________________ 11.21.2009 request at help desk to close acct. PW chgd, notifications removed. DOB 04.08.1960

19-11-2008, 07:47	#12
James S Moderator Moderator Join Date: May 2008 Location: I live in Yemen...the boats in Lebenon Boat: 1978 CT48 Arctic Lady Posts: 1,955 Images: 125	I think you’re right. I haven’t started yet with the hot & cold supply lines (still have to figure out what to do with the WH) but when I do, it will most probably be CPVC and definitely insulated. Do you have any more pics of your boat?

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