Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 22-09-2009, 10:47   #1
Vendor
 
witzgall's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,773
Fresh Water Pump Direction?

Hi all;

I replaced our hot water heater this weekend. It has an engine circuit. The water is not heating up. I think it is because of air in the lines, but I am also not sure if I hooked up the two lines correctly. So my question:

Does the water pump pump water TO or from the heat exchanger? I would think to but they are not labeled.

This is on a Volvo 2002 18hp diesel inboard.

Any tips on getting the air out?

Thanks in advance,

Chris
__________________

__________________
witzgall is offline   Reply With Quote
Old 22-09-2009, 10:54   #2
Moderator Emeritus
 
Pblais's Avatar

Join Date: Mar 2003
Location: Hayes, VA
Boat: Gozzard 36
Posts: 8,700
Images: 15
Send a message via Skype™ to Pblais
The water pump pressurizes the water system directly from the tank. You usually have a fresh water strainer before the tank to protect the pump. The normal water pressure will move water into the tank as you draw hot water. Engine coolant needs to flow through the water water heater to heat the water. The flow of that coolant could be the problem assuming you have fresh water flowing as well. The water heater does not really do anything except hold the hot water until used.
__________________

__________________
Paul Blais
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
Pblais is offline   Reply With Quote
Old 22-09-2009, 10:59   #3
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,318
The engine coolant circulates through a coil of tubing in the hot water heater, so it really doesn't matter which way you hook it up. Pull the hose at the highest point and add water. You should be able to feel the hose get warm as the engine heats up--it gets warmest fastest where the coolant exits the engine.
__________________
donradcliffe is offline   Reply With Quote
Old 22-09-2009, 11:00   #4
Vendor
 
witzgall's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,773
Hi Paul;

Yes, I realize the function of each circuit. I should clarify. There are two hoses running form the engine to the water heater. One is directly after the coolant pump. the other attaches to front-top of the engine. Coolant is flowing through the engine, but not through the lines going to and from the engine. They are hot at the engine connections, but not at the connections to the hot water heater.

The heater we replaced was working, but original, so I replaced it. It turns out it was COPPER!!! I could have kept it forever, but it sure looked old.

Chris
__________________
witzgall is offline   Reply With Quote
Old 22-09-2009, 14:47   #5
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,826
Under normal conditions, the coolant will flow through the lines as soon as the engine's thermostat starts to open. It could be a defective thermostat, gasket catching the thermostat, clogged lines, maybe a plug in the heater connectors that didn't get removed, etc.

Steve B.
__________________
senormechanico is offline   Reply With Quote
Old 22-09-2009, 17:52   #6
Vendor
 
witzgall's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,773
Would it be possible that the thermostat was not opening, and this was normal? Outside temps were ~80 degrees F, the seawater might be 75? and I ran the engine at idle for 30 minutes. This thought crossed my mind, but I just figured that the engine HAD to warm up in that time period. Maybe I am wrong?

Chris
__________________
witzgall is offline   Reply With Quote
Old 22-09-2009, 18:13   #7
Eternal Member
 
Chief Engineer's Avatar

Join Date: Aug 2006
Location: North of Baltimore
Boat: Ericson 27 & 18' Herrmann Catboat
Posts: 3,798
You need to find out what the circulating pattern of your freshwater side is.

A volvo shop manual should show you this.
__________________

__________________
Chief Engineer is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Westerbeke 10 Two Fresh Water Pump baymed1 Engines and Propulsion Systems 6 29-07-2009 06:10
fresh water pump air lock? limmer Engines and Propulsion Systems 7 25-07-2008 02:09
Fresh water pump - How many GPM? stoupidmonkey Construction, Maintenance & Refit 6 09-02-2008 05:07
fresh water pump teamivey Construction, Maintenance & Refit 7 11-02-2006 20:37



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:52.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.