Reply
 
Thread Tools Search this Thread Display Modes
 
Old 03-11-2018, 07:15 PM   #1
Veteran Member
 
City: Seattle
Vessel Name: Lesser Light
Vessel Model: Nordic Tug 32
Join Date: Sep 2017
Posts: 38
Water heater discharging through relief valve

I have an interesting problem to lay out there for all of you.

My 6-gallon Kuuma (now Force 10) water heater seems to be discharging quite a bit of water through it's pressure-relief valve - this water is discharged via tubing into the bilge and then get pumped out with the bilge pumps. I'm talking gallons of water, not drips - over days.

Any suggestions - is this likely to be the valve itself?

Anybody had anything like this happen?
Foster Nordic is offline   Reply With Quote
Old 03-11-2018, 07:52 PM   #2
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,834
The valve is a safety. It releases either from excessive pressure or temperature. If it is releasing and then resealing, it would be important to understand why before attempting to solve the problem.

Has it always done this?
How old is the unit?
Have you changed anything else in the plumbing?
How hot does the hot water get?
Is there a heat loop off the engine?
Does it happen on shore power, engine heat loop, or both?

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 03-11-2018, 08:26 PM   #3
Veteran Member
 
City: Seattle
Vessel Name: Lesser Light
Vessel Model: Nordic Tug 32
Join Date: Sep 2017
Posts: 38
All good questions, thanks:

Has it always done this? - I don't know I just bought the boat and became aware of it after having it a couple months.


How old is the unit? - its a 2008 Nordic Tug and I think everything is original

Have you changed anything else in the plumbing? - nothing has changed

How hot does the hot water get? - water seems to get warm for showers but not what I'd call "hot"

Is there a heat loop off the engine? - yes there is a heat loop from the engine that passes through the water heater

Does it happen on shore power, engine heat loop, or both? - good question and I don't know the answer. I'm only aware of it at the dock....

thanks!
Don
Foster Nordic is offline   Reply With Quote
Old 03-11-2018, 08:34 PM   #4
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,834
Ok, round 2.

When you run a faucet, does the pump run almost all the time?
Do you have an expansion tank or pressure tank in the system?
Is the water pump original?
If it was replaced, do you know if it's one of the newer variable speed pumps that don't require a pressure tank?

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 03-11-2018, 08:39 PM   #5
Guru
 
BruceK's Avatar
 
City: Sydney
Vessel Name: Sojourn
Vessel Model: Integrity 386
Join Date: Oct 2011
Posts: 13,329
My relief valve(on the boat HWS) suffers occasional incontinence,often resolved by just rotating the valve center. That I can rotate it might be a sign of trouble in itself, but it maybe worth a try.
__________________
BruceK
2005 Integrity 386 "Sojourn"
Sydney Australia
BruceK is offline   Reply With Quote
Old 03-11-2018, 08:48 PM   #6
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,834
To the OP,

Are you hooked to city water or pumping from your fresh water tank?
If hooked to city watet, how's the pressure?

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 03-11-2018, 09:05 PM   #7
Senior Member
 
Oldersalt's Avatar
 
City: San francisco
Vessel Name: Pacific Star
Vessel Model: 1990 Grand Banks 32 #834
Join Date: Jun 2016
Posts: 204
I had a similar problem on my 25-year-old Raritan 12-gal water heater. Relief valve would "burp" water into bilge fairly often. Called Raritan and they sold me a new relief valve. Easy replacement. Problem solved. Your problem may be caused by excessive temperature or pressure, but as a last resort it is easy to just replace the valve.
Oldersalt
"Everything on your boat is broken. You just don't know it yet."
Oldersalt is offline   Reply With Quote
Old 03-11-2018, 09:16 PM   #8
TF Site Team
 
koliver's Avatar
 
City: Saltspring Island
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 5,663
Replace the valve. Easy to DIY, not expensive. That will stop it burping.
__________________
Keith
koliver is offline   Reply With Quote
Old 03-11-2018, 09:16 PM   #9
Veteran Member
 
City: Seattle
Vessel Name: Lesser Light
Vessel Model: Nordic Tug 32
Join Date: Sep 2017
Posts: 38
Ok, round 2.

When you run a faucet, does the pump run almost all the time? - yes I think it does

Do you have an expansion tank or pressure tank in the system? - I don't think there is an expansion tank anywhere

Is the water pump original? - yes water pump is original Jabasco pump from 2008

If it was replaced, do you know if it's one of the newer variable speed pumps that don't require a pressure tank?
Foster Nordic is offline   Reply With Quote
Old 03-11-2018, 09:22 PM   #10
Guru
 
AusCan's Avatar
 
City: Adelaide
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 3,218
The seat of the relief valve probably has some corrosion/dirt on it. You may clear it by manually lifting the stem off the seat (manually opening the relief valve). Or as others suggest, just buy a new one. They are cheaply made and have a short lifespan.
AusCan is offline   Reply With Quote
Old 03-11-2018, 09:47 PM   #11
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,834
Ok, here is some information to help you solve the mystery.

When you heat water it expands (think of your engine, the coolant system, and the overflow tank). The water in you water heater expands when you heat it, and has to have some place to go. Without some place to go the pressure builds and goes out the safety valve (as it should ). For the age of your vessel, it most likely was built with a water pressure tank and a pump that turns on and off. The pressure tank has a bladder in it. On one side is the water and the other is air. The top of the tank has a tire stem valve to pressurize the bladder.

From your description of the pump running all the time when a faucet is open, I believe the pressure tank may have lost its air charge or the bladder may have failed. With no air space to compress, there is no place for the expanding hot water to go (except out the safety valve).

If it were my boat, I would look again for a pressure tank. Understand that they can be quite small. Saw one a couple of months ago on an American Tug 34 that was only about the size of a 1 quart soup can (it was black ).

BTW, as others have suggested, you can replace the safety valve. But if the expanding hot water has no place to go, it won't solve your problem.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 03-11-2018, 09:55 PM   #12
Veteran Member
 
City: Seattle
Vessel Name: Lesser Light
Vessel Model: Nordic Tug 32
Join Date: Sep 2017
Posts: 38
OK - so if I find a pressure tank (even small one) - then what; replace the pressure tank?

And I do understand it's very easy to also replace the relief valve.

Thanks for all this thought - hugely helpful to get others insights!

Thanks all!
Don
Foster Nordic is offline   Reply With Quote
Old 03-11-2018, 10:31 PM   #13
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,834
Quote:
Originally Posted by Foster Nordic View Post
OK - so if I find a pressure tank (even small one) - then what; replace the pressure tank?

And I do understand it's very easy to also replace the relief valve.

Thanks for all this thought - hugely helpful to get others insights!

Thanks all!
Don
If you find the pressure tank, I would first try to recharge it. This is accomplished by turning the pump off and opening a faucet until the water all but stops flowing. Leave the faucet open. Pump the tire valve on top of the tank up to the recommendation on the tank or about 25 psi (a bicycle tire pump is fine, but pressure is important. Too much defeats the purpose ). Close the faucet and turn the pump back on. When the pump stops running, open the faucet to a modest flow (fill a drinking glass in about 15 seconds). Then listen for the pump to cycle. Note how long it cycles on and off.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 03-11-2018, 10:37 PM   #14
Guru
 
OldDan1943's Avatar
 
City: Aventura FL
Vessel Name: Kinja
Vessel Model: American Tug 34 #116 2008
Join Date: Oct 2017
Posts: 10,595
Look on HP side of the F/W pump for the expansion tank.
__________________
Two days out the hospital after a week in the hospital because of a significant heart attack.
OldDan1943 is offline   Reply With Quote
Old 03-12-2018, 07:10 AM   #15
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 22,553
"Understand that they can be quite small."

Many of the older accumulator tanks do not have a schrader valve to pressurize or even a diaphragm.

The hassle is the air in the unit is eventually absorbed by the water .

All that is required is to take off the hose on the bottom of the cylinder , let the water drain and hook it up again.

This will restore the air inside.If it worked fine so far you are done.

An upgrade would be a tank that does have a diaphragm and air pressure inlet
FF is offline   Reply With Quote
Old 03-13-2018, 07:24 AM   #16
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 5,037
I would replace the valve as a first attempt. A bit of debris will keep it from sealing.
This can be a home depot, etc valve.
__________________
Jay Leonard
Ex boats: 1983 40 Albin trunk cabin, 1978 Mainship 34 Model 1
New Port Richey, Fl
jleonard is offline   Reply With Quote
Old 03-13-2018, 07:28 AM   #17
Guru
 
OldDan1943's Avatar
 
City: Aventura FL
Vessel Name: Kinja
Vessel Model: American Tug 34 #116 2008
Join Date: Oct 2017
Posts: 10,595
Yesterday I had over 50 messages from this site and 30 spam.
I learn more from the post here.
__________________
Two days out the hospital after a week in the hospital because of a significant heart attack.
OldDan1943 is offline   Reply With Quote
Old 03-13-2018, 09:14 AM   #18
Guru
 
City: Carefree, Arizona
Vessel Name: sunchaser V
Vessel Model: DeFever 48 (sold)
Join Date: Apr 2008
Posts: 10,186
Call AT. They can tell you where the pressure tank is located, if there is one. It should be large, about 2 gallons or so. Until this question is 100% answered, we are all whistling in the dark.

BTW, does this "leak" occur with heater electric switch off?
sunchaser is offline   Reply With Quote
Old 03-13-2018, 09:36 AM   #19
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,834
Quote:
Originally Posted by sunchaser View Post
Call AT. They can tell you where the pressure tank is located, if there is one. It should be large, about 2 gallons or so. Until this question is 100% answered, we are all whistling in the dark.

BTW, does this "leak" occur with heater electric switch off?
OP would probably have better luck calling Nordic Tug.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 03-13-2018, 09:45 AM   #20
Guru
 
twistedtree's Avatar
 
City: Vermont
Join Date: Jan 2013
Posts: 10,092
Quote:
Originally Posted by jleonard View Post
I would replace the valve as a first attempt. A bit of debris will keep it from sealing.
This can be a home depot, etc valve.
Maybe, but also maybe not. The relief valves release on pressure and temp, but the temp part I think is optional. Also, there are different length temp probes for different configuration tanks, and I think also different temp release points. I had to replace mine on my Grand Banks (don't recall the tank mfg) and had to order the replacement. As I recall, all the info is on the tag on the valve. Grab the part number and start googling to see what you have, and hence what you need. The temp ratings can be significant if you have engine-heated water which will get much hotter than electric heat. A household tank will never get over 150 or 160F, where a marine tank with engine heat can easily reach 190-200F, or whatever your engine temp is.
__________________
MVTanglewood.com
twistedtree is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 05:25 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012