Sea Ranger 46 by King Yachts, water tank issues

I recently purchased a 1990 Sea Ranger 46 aft cabin (King Yachts version) and working through the usual sorting out issues you would find on a 30 year old boat.
The water tanks, one 800 litre under the aft cabin berth and a 700 litre running between and under the engines (3208 NA Cats) are coughing and spluttering through sink fawcets when the tanks are 2/3's full, but once refilled again, flow properly?!
The aft tank sits higher than the engine room tank, both the discharge pipes join at a T fitting and then into the pump.
The boat has only been used lightly and in calm waters for the last 23 years by the PO, last weekend we had her rolling in a beam/quartering sea and noticed the fresh water flushing toilet had dirty water coming through the system.
Could this mean a sediment blockage somewhere?
Anybody else encountered this problem before?

Cheers SB

I hope you have drains on the bottom of your FW tanks. If so, Iran and flush them repeatedly....

SB
As Dan says, flush the tanks and you likely want to treat the water system with bleach. What material are the tanks? What is the pump and pressure tank setup? Sounds like you're sucking air somewhere

Also, before the T connection are their isolating valves so you can draw from either or both? If so this provides the opportunity to assess each tanks "health" or balance for trim.

BTW it is nice to have that water volume.

Any galvanized fitting in the system is rusting inside.


See if you can find them and R&R.

FF said:

Any galvanized fitting in the system is rusting inside.


See if you can find them and R&R.

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Bronze fittings or some sort of plastic material.... unless you live in California.... Seems everything can give you cancer. SHRUG.

Yeah, the little bit of lead that makes a brass/bronze alloy easier to cast has caused some sort of conniption in certain places.

Check your vents. The screens could be plugged or the hoses kinked. When the FW pump starts gurgling, open the fill cap to vent.

It seems like you're sucking air from the tank siting between the engines. It's most probably a top mounted pickup tube. Sometimes they rust and develop pin holes along the pickup tube. As long as the level is over the hole, it works fine. When it gets lower than the hole, you start picking up air. I suspected that in my water tank and went in with a snake camera. Turned out to be something else in my case but it's frequent if the tube is made of steel. Other possibility is that your pump is just not strong enough to pull that far from the tank. When it's full, it's easier for the pump to pull water. That was my case. Hope it helps. You should have a valve to switch from one tank to the other. Otherwise, when one is empty, you will start sucking air...

OldDan1943 said:

Bronze fittings or some sort of plastic material.... unless you live in California.... Seems everything can give you cancer. SHRUG.

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Live to be 100 years old and prove California wrong.

I remember when tooth paste tubes were made of a soft lead alloy.
They just quietly disappeared without the benefit of the lawyers.

Thanks for the quick responses so far, appreciate the comments. I live three hours from the boat, just here for the day and thought I'd put the question out there.
The tanks are SS, both have inspection hatches, shutoff valves and sight tubes. The pump is a Shurflo 3 GPM. The aft tank fills from the stb deck and the lower ER tank fills from the port side deck.
The PO only filled the aft tank for some reason, and again, just short period cruising, never testing or thinking about the entire system, in fact he didn't realise there was a lower, ER tank?

RichardM said:

It seems like you're sucking air........... You should have a valve to switch from one tank to the other. Otherwise, when one is empty, you will start sucking air...

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It looks as though you are onto it Richard, after lifting off the aft cab bed etc, shut off the tank valve, it's flowing fine from the ER tank (btw just measured it and it's only 400 litres, although marketed as 700 ).
Not sure where to go from here, all the plumbing of course is either under the aft bed or under ER sole, I'll have to look into some kind of a remote control valve to regulate flow from either tank.
In the mean time giving the tanks a good flush, thanks again for all the contributions, I appreciate the support.

Water tanks generally should drain from the bottom, so sucking air really shouldn't be an issue. To me it sounds like your pump is getting lazy. If it was sucking air it probably would never shut off.

First off I would totally drain the tanks, rinse and drain again. I add about a half cup of unscented bleach per 150 gallons or so. Add the bleach after you fill the tanks halfway. (Undiluted Bleach will eat holes in unprotected stainless)

Spitting and coughing is probably the pump.

pete

Southern Boater said:

...The tanks are SS, both have inspection hatches, shutoff valves and sight tubes. The pump is a Shurflo 3 GPM. The aft tank fills from the stb deck and the lower ER tank fills from the port side deck.
The PO only filled the aft tank for some reason, and again, just short period cruising, never testing or thinking about the entire system, in fact he didn't realise there was a lower, ER tank?

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Hi SB, you are now using the tank the PO didn`t use/know of. Was the ? larger aft one he used functioning ok, or was it only seen/checked when full? If both work ok individually, why not together?
Our boat has 4 tanks, one each side, one fwd one aft. All valves left open I can pretty much fill all 4 (total 1000L) from one. Though the manual does says to turn off empty ones.
S/steel tanks etc in a 30yo boat is impressive, speaks well of the build quality.

BruceK said:

Hi SB, you are now using the tank the PO didn`t use/know of. Was the ? larger aft one he used functioning ok, or was it only seen/checked when full? If both work ok individually, why not together?
Our boat has 4 tanks, one each side, one fwd one aft. All valves left open I can pretty much fill all 4 (total 1000L) from one. Though the manual does says to turn off empty ones.
S/steel tanks etc in a 30yo boat is impressive, speaks well of the build quality.

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Not sure why they don't work together yet Bruce, more trial and error to work out the many systems. Some folks have suggested the pump may not be up to it, I've been running it continuously to flush the tanks today, but gave up in case it fails? I'll buy a spare one as back up.

If there a thread explaining how to post pics, I could put some up.

Southern Boater said:

Not sure why they don't work together yet Bruce, more trial and error to work out the many systems. Some folks have suggested the pump may not be up to it, I've been running it continuously to flush the tanks today, but gave up in case it fails? I'll buy a spare one as back up.

If there a thread explaining how to post pics, I could put some up.

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Do the tanks feed the pump from top or bottom outlets? Are there not tank bottom plugs or drains so you don't need to run the pump to empty tanks?

sunchaser said:

Do the tanks feed the pump from top or bottom outlets? Are there not tank bottom plugs or drains so you don't need to run the pump to empty tanks?

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Good point sc, they do both feed from and also have seperate drains from the bottom, so will drain off rather than pump out next time I’m down in a few days. I wanted the bleach solution to also flush the lines to the various fawcets around the boat as well.

They say every day is a school day, it’s such a great help having the knowledge to draw on from the TF community, cheers

Southern Boater said:

Good point sc, they do both feed from and also have seperate drains from the bottom, so will drain off rather than pump out next time I’m down in a few days. I wanted the bleach solution to also flush the lines to the various fawcets around the boat as well.

They say every day is a school day, it’s such a great help having the knowledge to draw on from the TF community, cheers

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No bleach.... Get some hydrogen peroxide "bleach like stuff" from the grocery store.

OldDan1943 said:

No bleach.... Get some hydrogen peroxide "bleach like stuff" from the grocery store.

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Why not bleach? Cl systems seem the norm for water treatment.

Peroxide has less risk of damaging metal components in the system, as it's less corrosive.

Spitting and coughing doesn't sound like a pump problem. Sounds like it is getting air. if the pump has a leak in the housing it could a pump problem, although you said it runs fine with one tank isolated. Concentrate on the tank and lines that the problem shows up with. If the the lines are allowing it to suck air when running, they will most likely be leaking water when off. If a visual inspection of the lines is not possible, then maybe try a temporary line. This will be the lines between the pump and tank. Also, check the valves, often valves will leak at the packing when open but not when closed, or vice versa. If the tank has a dip tube from the top then the dip tube is suspect, especially if it starts coughing and spitting when 2/3 full.

rslifkin said:

Peroxide has less risk of damaging metal components in the system, as it's less corrosive.

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TWedd said:

Spitting and coughing doesn't sound like a pump problem. Sounds like it is getting air. if the pump has a leak in the housing it could a pump problem, although you said it runs fine with one tank isolated. Concentrate on the tank and lines that the problem shows up with. If the the lines are allowing it to suck air when running, they will most likely be leaking water when off. If a visual inspection of the lines is not possible, then maybe try a temporary line. This will be the lines between the pump and tank. Also, check the valves, often valves will leak at the packing when open but not when closed, or vice versa. If the tank has a dip tube from the top then the dip tube is suspect, especially if it starts coughing and spitting when 2/3 full.

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Thanks for the reply TW, you have raised some good points, I will check the lines forward of the tanks, all easily accessed. A deck wash pump has been grafted into the fw supply line right near the house supply pump, so maybe there is a leak around there?
Although as mentioned, a cleaner flow resulted from isolating each tank

Southern Boater said:

Thanks for the quick responses so far, appreciate the comments. I live three hours from the boat, just here for the day and thought I'd put the question out there.
The tanks are SS, both have inspection hatches, shutoff valves and sight tubes. The pump is a Shurflo 3 GPM. The aft tank fills from the stb deck and the lower ER tank fills from the port side deck.
The PO only filled the aft tank for some reason, and again, just short period cruising, never testing or thinking about the entire system, in fact he didn't realise there was a lower, ER tank?

Click to expand...

I have 2 forward tanks, and to aft tanks (300 gl total). because the aft tanks are slightly higher (under master bunk vs under the floor in the front) I can fill the entire system by filling the aft tank fill only. Provided all valves are open and I fill slow enough for water to flow to the forward tanks. That MIGHT have been what the PO was doing if the ER tank is lower.

"Yeah, the little bit of lead that makes a brass/bronze alloy easier to cast has caused some sort of conniption in certain places."


Its not easier to cast the alloy is called "Free Machining Bronze" because it is faster to machine.

Yes, I was confused. Recently working with aluminum alloys with copper added and assumed incorrectly.

jgtrucking said:

I have 2 forward tanks, and to aft tanks (300 gl total). because the aft tanks are slightly higher (under master bunk vs under the floor in the front) I can fill the entire system by filling the aft tank fill only. Provided all valves are open and I fill slow enough for water to flow to the forward tanks. That MIGHT have been what the PO was doing if the ER tank is lower.

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Not sure the PO actually knew there was a second ER tank, his comment to me was THE tank can either fill from the port or stb filler.

Anyhow, the spluttering has stopped with the isolation of one of the tanks, and just drawing from one. Trying to track down a fresh water leak, originally thought it may have been the lower ER tank, but it appears to be on the pressure side of the aft head, probably shower supply.
Oh well, another project to track down