Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-18-2021, 07:06 PM   #1
Lt. Commander
 
PJHoffnet's Avatar
 
Join Date: Feb 2017
Location: Merritt Island, FL
Posts: 186
Default Installing Dometic DTM08 two tank level indicator system

Since we're not doing anything longer than three or four day trips because of COVID, I'm continuing to knock out those little things "I'd like to do" type projects (not spending money on fuel, so might as well spend it on other stuff).

Our black water tank (70 gal) has a simple 'Tank is full' light - Dometic DTM01 system. Basically a light comes on when the level is about two inches from the top of the tank. Since we'd pull in for fuel every few days when cruising that two inches has never been a problem, and provided plenty of warning. One thing I didn't like about it was not knowing how 'empty' the tank was when we were off shore and I ran the macerator and pumped overboard. I wanted a better feel for the tank level as it was empting. The boat has an analog gauge for the potable water tank - but figured, might as well put in the same system for it too.

Purchased the Dometic DTM08 system and two three inch adapter flanges.

First job was to build a wire harness to go from the tank level probes to the display panel. There’s some minor modification (flipping of probe sensor magnets) that you need to do to differentiate the black water (filling triggers lights) and potable water tank (empting triggers lights). Bench testing everything before getting started was fairly easy.

Next, time to access both of the tanks. They’re located under the rack in the aft cabin of our 4100 SCA - a bit of a pain. Lots of angle bracket screws to take off the top of the bed frame - of which I’m only putting a few back in.

The potable water tank is easily accessed - it’s above the deck in the middle of the rack. The black water tank, on the other hand, is under the deck, at the foot of the rack, under the pull out drawers. So, remove the drawer, remove a ‘false floor’ - basically a ‘base’ of the bed frame, then cut through the carpet & deck to expose the top of the tank.

After cutting holes to accept the adapter flanges, cutting the ‘empty’ and ‘half full’ level rods to length was super easy. Cutting a bulkhead to install the display panel was easy. As with most projects running the wiring was the biggest job involving the usual contortionist maneuvers in the bilge area and use of a fish tape and chase strings. In the end everything went in nicely and works/looks great. Certainly not a ‘needed’ upgrade, but a nice project we enjoyed working on.

Aft cabin rack ‘opened up’ to expose the potable water tank (here with probe already installed). You can see the drawer removed at the foot of the bed to get to the black water tank.


Exposing the top of the black water tank.


Black water tank flange installed - you can see the old DTM01 probe also.


Tank level probe cut to length and ready to go into the black water tank.


Display
__________________

__________________
Paul
Changes in L'Attitudes
1999 Maxum 4100 SCA
PJHoffnet is offline   Reply With Quote
Old 02-18-2021, 11:58 PM   #2
Lt. JG
 
Join Date: Mar 2017
Posts: 32
Default

How did you prevent debris from falling into the tank when you cut the holes?

Also do you have details on the bulkhead fitting you used and how you sealed it to the tank?


Sent from my iPhone using Tapatalk
__________________

yahoo82 is online now   Reply With Quote
Old 02-19-2021, 05:09 PM   #3
Lt. Commander
 
PJHoffnet's Avatar
 
Join Date: Feb 2017
Location: Merritt Island, FL
Posts: 186
Default Good questions ...

Quote:
Originally Posted by yahoo82 View Post
How did you prevent debris from falling into the tank when you cut the holes?
The only debris that fell into the tank were some fairly fine/Curly-Q-like threads of plastic generated by the hole saw. For the potable water tank, I used a small fish tank dip net (cheapy I bought just for this job, rinsed in bleach) to just scoop out the pieces. In the black water tank, I just left them Since their are no 'skinny' runs or filters between the tank and the shore pump out connection, no need to worry. I'll be sure to flush/pump out the tank several times before I run the macerator for overboard discharge.

Quote:
Originally Posted by yahoo82 View Post
Also do you have details on the bulkhead fitting you used and how you sealed it to the tank?
I used the Dometic three inch tank adapter flange. My research seemed to imply that newer Dometic tanks have 'inspection' ports built in which the probes can screw into, but my tanks were older and did not have them.
__________________
Paul
Changes in L'Attitudes
1999 Maxum 4100 SCA
PJHoffnet is offline   Reply With Quote
Reply

Tags
4100 sca, tank level

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


Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 12:37 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.