High Water Alarm

[Newtrawlerowner]

2003 MS 400
Does anyone know what trips the high water alarm?
I tried lifting the auto switch on the main pump right above the propeller shaft. This is the largest of the sumps. The pump comes on, the light on both helms illuminates, but the high water alarm does not sound. I've tested using the switch at each help and the alarm does sound.
Anyone know where the high water sensor is located?

 

[rgano]

On my boat the float switch is the high water alarm on the 4000 GPH "Emergency Pump." It activates the light at the helm switch as well as the audible alarm. I think you have a faulty audible alarm or a loose connection.

 

[SteveK]

On mine the high alarm float switch is separate from the one that normally operates the pump. If this 2nd one lifts then it sounds the high alarm warning

 

[OldDan1943]

2003 MS 400
Does anyone know what trips the high water alarm?
I tried lifting the auto switch on the main pump right above the propeller shaft. This is the largest of the sumps. The pump comes on, the light on both helms illuminates, but the high water alarm does not sound. I've tested using the switch at each help and the alarm does sound.
Anyone know where the high water sensor is located?

On my boat, ..... the high water alarm is above the normal 'turn on point' for the bilge pump, indicating the bilge pump has either failed or there is flooding in the compartment more than the bilge pump can pump.

May I suggest, you install a bilge pump counter that reads out at the helm. When you return to the boat, it is always nice to know if and how many times the bilge pump turned on both sitting at the dock and underway.

My high water alarms tigger a 4inch fire bell......

 

[DavidM]

You should have a helm switch with test, normal and off settings. My Pilot 34 of the same year did. Then try it in test and see if it alarms. Then if so return it to normal.

My high water alarm was triggered by a float switch in the aft near the shaft log that triggered the bilge pump as well as the alarm. If the dash switch works in test, it should also trigger the bilge pump, so turn it on, listen and you should find it.

David

 

[OldDan1943]

Currently each of my bilge pumps have a 3 position switch. Normal/OFF and momentary ON.
I would rather have Normal/OFF and ON. If the high water alarm goes off, I would turn ON the blige pump and go investigate the problem.
I not sure why there is an OFF position.

 

[Dougcole]

The HW alarm on the 400 is triggered by the float switch on rhe HW pump, which is all the way aft in the ER, the bigger pump, mounted higher. When you activate that float switch the alarm should sound.

The HW alarm system on the MS 400 is a mess. You can search my posts to find more info on it. I hope you don’t face the same issues I did.

 

[OldDan1943]

The HW alarm on the 400 is triggered by the float switch on rhe HW pump, which is all the way aft in the ER, the bigger pump, mounted higher. When you activate that float switch the alarm should sound.

The HW alarm system on the MS 400 is a mess. You can search my posts to find more info on it. I hope you don’t face the same issues I did.

LOL when I bought this AT, it had one bilge pump in the ER. I added 3 more, fwd bilge, tank room (aft of the ER) and the aft lazarett. Each have their own through hull.
I do have a spare bilge up with along wire and alligator clips and a long discharge hose to at least get the water on deck.

 

[Alaskaflyer]

Currently each of my bilge pumps have a 3 position switch. Normal/OFF and momentary ON.
I would rather have Normal/OFF and ON. If the high water alarm goes off, I would turn ON the blige pump and go investigate the problem.
I not sure why there is an OFF position.

Fuel spill?

 

[OldDan1943]

Fuel spill?

Okay, now that's a valid reason.

 

[Bacchus]

The HW alarm on the 400 is triggered by the float switch on rhe HW pump, which is all the way aft in the ER, the bigger pump, mounted higher. When you activate that float switch the alarm should sound.

The HW alarm system on the MS 400 is a mess. You can search my posts to find more info on it. I hope you don’t face the same issues I did.

This is fairly consistent with different Mainship models in this era. Apparently not for other manufacturers based on comments.
My '08 MS 34 HT is similar except for location. My high water / high flow pump & sensor is under the fuel tank ahead of the engine and mounted 4-5" higher than the other pump & sw in this chamber. On some MS models they also triggered the alarm if power was lost to the high water pump. They powered the alarm from one house batty and pump from the second. There is a whole mess of relays in the elec cabinet that provides the logic. The high water pump (manual or auto) should also trigger all other pumps on.

 

[hmason]

My Johnson Pump high water alarm has nothing to do with the bilge pumps. It has an electronic water sensor which when wet sounds the alarm.
https://www.spxflow.com/johnson-pump-marine/products/high-water-alarms

Scroll down the page, it's called "Bilge Alert with Sensor. If the alarm goes off you will know and if you have a dog, the dog will go nuts---a backup system for sure.

 

[Newtrawlerowner]

The HW alarm on the 400 is triggered by the float switch on rhe HW pump, which is all the way aft in the ER, the bigger pump, mounted higher. When you activate that float switch the alarm should sound.

The HW alarm system on the MS 400 is a mess. You can search my posts to find more info on it. I hope you don’t face the same issues I did.

Doug,
After I made my post I saw your thread and read the entire string One thing mentioned was 4 pumps. I only have 3. I will test the alarm on the largest higher mounted pump on the aft bulkhead.

 

[Dougcole]

Doug,
After I made my post I saw your thread and read the entire string One thing mentioned was 4 pumps. I only have 3. I will test the alarm on the largest higher mounted pump on the aft bulkhead.

You should have four in a 400, one in the laz under the gen set, one in the ER all the way aft, the HW pump which is above that one and the fwd pump which is in a sump under the companionway steps, it's under the washer/dryer if you have one.

 

[Bacchus]

You should have four in a 400, one in the laz under the gen set, one in the ER all the way aft, the HW pump which is above that one and the fwd pump which is in a sump under the companionway steps, it's under the washer/dryer if you have one.

Even my 34HT has 4 in addition to the high water pump?

 

[Cartouche]

You should have four in a 400, one in the laz under the gen set, one in the ER all the way aft, the HW pump which is above that one and the fwd pump which is in a sump under the companionway steps, it's under the washer/dryer if you have one.

There is 4 on a 390 and HW is in front of engine up high and when float activates sound and light come on at both helms

 

[twistedtree]

My high water / high flow pump & sensor is under the fuel tank ahead of the engine and mounted 4-5" higher than the other pump & sw in this chamber.

Mine is set up the same way. The "normal" pump is lowest and turns on with it's own float switch. Then there is a second much larger pump with a float switch that is couple of inches higher. When the second pump runs, so does the alarm.

 

[boan400]

Drawing Bilge main circuit

2003 MS 400
Does anyone know what trips the high water alarm?
I tried lifting the auto switch on the main pump right above the propeller shaft. This is the largest of the sumps. The pump comes on, the light on both helms illuminates, but the high water alarm does not sound. I've tested using the switch at each help and the alarm does sound.
Anyone know where the high water sensor is located?

Try to contribute with electrical diagram for the main circuits from our 400 we got from the factory in may 2005.
Some years ago all the alarm buzzer suddenly went on. The boat was at the dock. We have our boat in Sweden but at that time I was in US at a Trawel Feast. My brother had a hard time to quiet all the 4( or 5?)buzzers in the boat.
Then I made this drawing. There is more to say but I try to send this message becuse I’m uncertain if I got the enclosed pics.