A holding tank sensor lesson for Hunter 36 owners and maybe others

[Dan_Y]

I thought the wema holding tank sensor had failed when we bought our used h36 because we had used the head several times with no indication above E on the panel meter. I ordered one from SBO based on the old sensor p/n. Interestingly, the sensor is only 8" long in a 16" deep tank. Being slow as I am, I realized the old sensor didn't register until the tank had at least 8" of fluid. I was as pissed at HM as I was at myself for not noticing this issue when pulling the old p/n for Phil. Given the way the tank is mounted, there is just enough room to pull the old 8" sensor, but would be impossible to insert a 12 or 15" sensor. BUT had they placed the mounting hole even a foot forward of the existing location, I could mount a 24" sensor, no problem..haha. Probably should have plugged the hole and put an external capacitive sensor in it's place down the full depth of the tank, but wondered about compatibility with the wema display that also measured fresh water tank levels.

Peggy is right when she says that boat builders are horrible sanitation system engineers. My head discharge hose also runs uphill to the holding tank and cannot drain the entire hose into the tank. So I put holding tank treatment in two bowls of water and flush those through at the end of an outing so fresh water sits in the hose. Tank treatment probably doesn't do much in the hose due to lack of air...but makes me feel like I'm doing something from keeping the trident 101 hose from permeating prematurely. In retrospect, i should have investigated an alternate hose routing.

 

[Peggie Hall HeadMistress]

My head discharge hose also runs uphill to the holding tank and cannot drain the entire hose into the tank. So I put holding tank treatment in two bowls of water and flush those through at the end of an outing so fresh water sits in the hose. Tank treatment probably doesn't do much in the hose due to lack of air...but makes me feel like I'm doing something from keeping the trident 101 hose from permeating prematurely. In retrospect, i should have investigated an alternate hose routing.

Yup...but it's not that hard to fix now. And I'll be glad to help you do it if you'd like to send me a PM.

 

[1998Hunter376]

Peggie,

Wondering what you mean is not hard to fix, the sensor, or the waste hose running uphill?. I bought a 1998 Hunter 376 last year and I think the hose has odor permeation... Starts out with white hose at the toilet, then after a foot or two it is fitted to a long black hose (similar to an exhaust hose) all the way to the tank. What hose should I replace it with? and I'll assume there is no remedy for it running uphill. My sensor never works either.

Charley in Ft. Pierce

 

[Peggie Hall HeadMistress]

Wondering what you mean is not hard to fix, the sensor, or the waste hose running uphill?. I

Both. Send me a PM and we'll schedule a convenient time to brainstorm the specifics of how to run your toilet discharge hose to solve that problem.

As for your tank level indicator, replacing it with a system that puts the sender on the OUTside of the tank is the solution that problem: Profile Tank Monitors

 

[1998Hunter376]

Thanks Peggie! Sorry for not knowing, but what is a PM?

 

[SFS]

PM is Private Message. Click on Peggie's logon, and then click on "send a private message".

 

[MitchM]

"I thought the wema holding tank sensor had failed when we bought our used h36 because we had used the head several times with no indication above E on the panel meter..." those WEMAs need to be pulled and cleaned each year end. get a disposable container you'll never use again, fill it with pretty hot water and dawn dishwashing soap. get an old toothbrush you'll never use again .. you might save 100$ for a new sensor.

 

[Peggie Hall HeadMistress]

Replacing it with a system that has senders that go on the outside of the tank means never have to pull a sender to clean it again. Profile Tank Monitors

 

[HernandoBeacher]

Yup...but it's not that hard to fix now. And I'll be glad to help you do it if you'd like to send me a PM.

Peggy,

Did you solve Dan_Y's issue with the long hose run on the H36? I was following the thread but was out of contact since November. Thanks, Rod

 

[Peggie Hall HeadMistress]

I'm sure we did, but since it needed discussion in more detail specific to his boat than is practical in open forum, I suggested we discuss it on the phone. I suggest you ask him.

Keep in mind though that every boat, even the same make/model, is different 'cuz builders and owners don't always do things the same way. So what worked for him may not work for you. If you need help, send me a PM and we'll talk.

 

[Dan_Y]

Rod -
While Peggy has generously given me advice on several issues, I have not contacted her directly with the details of my h36 waste water plumbing issues. I have to work thru some of the details to get answers to some questions I'm sure she would ask. I think of it as if i'm going to the teacher with a homework problem that I haven't tried to solve yet. Ha!
After rebuilding the factory electric head, replacing the sanitation lines, replacing the macerator and elevating it so it drains after use, and replacing the Wema holding tank sensor, I have moved on to other issues that are electrical in nature, like the lack of an ACR and auxiliary battery for emergency engine starting. The plumbing work took care of odor issues due to permeated factory hoses that were 7 years old. I find it irritating to see how the sanitation hose runs down hill (mostly) from the head to the base of the holding tank, to a few inches below it actually, only to have to go up hill almost 16-20 inches to reach the inlet of the holding tank. Lots of water sits in the hose.

I first need to determine where the top of the tank is in all possible alternative routes of the sanitation line so the sanitation line can be routed to maintain a negative grade to the top of the tank. Peggy said the electric head can pump pretty good, so pumping uphill a foot or two so at the beginning would help set up the downhill flow. I noticed that the wet closet next to the toilet has a mouse hole in it that enables access directly under the head, like it might have been there for a prior routing of the sanitation hose thru the bottom of the port cockpit locker. But it looks like the line needs to be at least a foot or more off the bottom of that locker in order to stay above the top of the holding tank. Also, the holding tank is on the starboard side and should be on the port side with the head, but there is much stuff in the port transom, including the two inaccessible isolation transformers and the fuel fill and vent lines. Having a new tank made is a good option (Peggy has cited a reliable source several times) that is maybe wider but lower profile to give me some downhill slope. This will not be an easy chore!
Dan

 

[Rafael8008]

​

Peggie,

Wondering what you mean is not hard to fix, the sensor, or the waste hose running uphill?. I bought a 1998 Hunter 376 last year and I think the hose has odor permeation... Starts out with white hose at the toilet, then after a foot or two it is fitted to a long black hose (similar to an exhaust hose) all the way to the tank. What hose should I replace it with? and I'll assume there is no remedy for it running uphill. My sensor never works either.

Charley in Ft. Pierce

Have what I believe is a very similar problem. My Hunter_376 (1998) has started to smell "gamey", and I think that the hose is a very likely candidate. So two of the May projects:

is to replace the hose​

replace the sensing system.​

I don't want to do a whole big engineering requirements analysis but have to ask:
Is there a cheap and cheerful sensor replacement that feeds a signal to the OE gauges? I would do water and holding tanks at the same time.
If not, does it make more sense to connect tank level transducer to the new Raymarine Axiom?
Any advice is appreciated

 

[Peggie Hall HeadMistress]

The SCAD tank level monitors are top rated Scad Tank Monitors and their two tank system can used for both water and waste tanks, read out on the same panel. You'd be wise to go with their gauge panel instead of trying to jury rig it to the OE gauges which have to be totally obsolete by now. SCAD systems are available from a number of sources including Amazon.

As for new hoses...that's the last thing you want to buy cheap if you only want to do this job ONCE instead of every few years. Raritan SaniFlex is the top rated sanitation hose...it's proven to be 100% odor permeation resistant--even has a 10 year warranty against it, plus it's so flexible it can be bent almost as tight as a hairpin without kinking, which makes most re-hosing jobs a whole lot easier. Defender has it in 1" and 1.5" for about $10/ft and they sell it by the foot, so you only have to buy the amount you need. Raritan Sani / Flex Sanitation Hose at Defender

A really thorough bilge cleaning that includes rinsing all the dirty water out will also help to eliminate the "gamy" smell on your boat.

--Peggie

 

[Rafael8008]

Thank you Peggy.
I've ordered the SCAD tank monitor and am most excited to have a reliable meter again.

The routing of the saniflex hose is quite intimidating to me.
there did not seem to be any pathway between the bare hull and the Queen bed base, that is readily accessible.
Yikes.
It looks as if I will have to remove all the cabinets in the aft cabin. .... unless I am missing something.

1998 Hunter 376

 

[Peggie Hall HeadMistress]

Maybe not. Send me a PM if you'd like to schedule some one-on-one brainstorming.

--Peggie

 

[chuckwayne]

Thank you Peggy.
I've ordered the SCAD tank monitor and am most excited to have a reliable meter again.

The routing of the saniflex hose is quite intimidating to me.
there did not seem to be any pathway between the bare hull and the Queen bed base, that is readily accessible.
Yikes.
It looks as if I will have to remove all the cabinets in the aft cabin. .... unless I am missing something.

1998 Hunter 376

unless it's different from the 356 the hose runs from the tank aft of the bulkhead, across the stern, then up the port side in the hull under the berth. It's secured with ty-raps along the way. I cut the ty-raps, found a coupler that fit inside the hose, ran the new hose in thru the head portlite and connected it to the old hose behind the head. with one person pushing and one pulling (me in the aft locker) we made a little slack in the old hose; I then quickly disconnected the old hose from the old tank and lifted it out the stbd hatch; plugged the tank. we lost very little liquid, what was in the hose just went into the new one. we then worked the new hose into position, then disconnected the coupler with the old hose-now empty. we dropped the hose end into position and connected it. lastly, we cut to length and connected to the head end and re-ty-rapped the new hose. worked well and cleanup was OK.