Word to the wise

chriscowles · 03-25-2021, 03:07 PM

When replacing the probes on your black tank, consider that it might contain some residual.

WanderMore · 03-25-2021, 03:15 PM

“Residual what...” he asked with a knowing grin

NJKris · 03-25-2021, 03:23 PM

no pics?

Reverse_snowbird · 03-25-2021, 03:50 PM

Quote:

Originally Posted by chriscowles

When replacing the probes on your black tank, consider that it might contain some residual.

Yuck!

Nitril gloves and a large bucket required for that job.

moff34 · 03-25-2021, 03:55 PM

Need we ask how you know this?

Sounds like a good story.

Hoomi · 03-25-2021, 04:00 PM

Ewwww.... icky-poo.

Another job that makes you glad your job isn't changing them at an RV service center?

chriscowles · 03-25-2021, 04:02 PM

Fortunately just a trickle and I was able to get out of the way. But I did the black tank before the gray tank and the gray tank is downhill, so I'm not doing the gray tank today.

chriscowles · 03-25-2021, 04:04 PM

Quote:

Originally Posted by Reverse_snowbird

Yuck!

Nitril gloves and a large bucket required for that job.

Taking a bath in hand sanitizer

NJKris · 03-25-2021, 05:04 PM

Wait. Your RV is a year newer than mine and you're doing that already??

D W · 03-25-2021, 05:17 PM

Now you know why a Plumber charges $100+/ hr when he comes to your house.

chriscowles · 03-25-2021, 05:30 PM

Quote:

Originally Posted by NJKris

Wait. Your RV is a year newer than mine and you're doing that already??

If you read my response in another thread about spending money on our trailer, it's my version of a hobby car. The possibilities of spending money on it are endless.

I'm replacing them while I have the bottom off the trailer for other reasons. I really don't want to take the bottom off again, and we've already gotten wrong information from the level gauges. Hopefully the Horst probes will be better. We'll see.

NJKris · 03-25-2021, 06:12 PM

I think I'm up to 6,500 bucks spending on a 17.5k trailer, lol, didn't see your other thread. Are these probes engineered differently than OEM? Mine work fine till things get city in the tank! Then don't work again properly till a good tank flush.

chriscowles · 03-25-2021, 07:39 PM

Quote:

Originally Posted by NJKris

I think I'm up to 6,500 bucks spending on a 17.5k trailer, lol, didn't see your other thread. Are these probes engineered differently than OEM? Mine work fine till things get city in the tank! Then don't work again properly till a good tank flush.

OEM tank liquid levels are measured with 4 electrical sensors on the wall of the tank. They're essentially the head of a bolt, held in the wall of the tank with Well nuts. Conductivity between them determines the tank level. Well nuts are rubber grommets of varying depth with a bolt through them. They're compressed by tightening a nut. The grommet expands on the back side and secures the Well nut in place.

The probes are wired to the control panel. The lowest level probe is the common wire and 3 others are increasingly higher on the wall are associated with the 1/3, 2/3 and full lights on the control panel. The weakness is that solids and paper stick to the wall, short out the probe and give bad information. Gray and fresh tank probes are the same and, despite the lack of solids, condensation on the wall of the tank shorts them out.

Horst Miracle probes (now owned by Valterra and marketed as Valterra Horst Probes) address the problem by putting the probe farther out into the tank and, in the case of the black tank, they're shrouded on the top. The theory is the shroud prevents solids from shorting the probe and being farther out into the tank prevents wall condensation from doing the same. Some people report success; others scoff. I guess I'll find out.

The pic below shows the black tank probe with the shroud and the fresh tank probe without. You have to be sure the black tank probe is installed with the open side down. Otherwise, it acts as a scoop, not a shroud. The bolt on the outside has a flat spot which indicates which side is up.

I installed black tank probes in all tanks because they were cheaper at the time I bought them. Shrouded probes will work in fresh and gray tanks but probes without shrouds won't work in black tanks. They'll just catch all the toilet paper floating around.

Edit: changed pictures

Scrapper · 03-25-2021, 07:44 PM

Quote:

Originally Posted by WanderMore

“Residual what...” he asked with a knowing grin

My guess is beer.

NJKris · 03-25-2021, 07:58 PM

Quote:

Originally Posted by chriscowles

OEM tank liquid levels are measured with 4 electrical sensors on the wall of the tank. They're essentially the head of a bolt, held in the wall of the tank with Well nuts. Conductivity between them determines the tank level. Well nuts are rubber grommets of varying depth with a bolt through them. They're compressed by tightening a nut. The grommet expands on the back side and secures the Well nut in place.

The probes are wired to the control panel. The lowest level probe is the common wire and 3 others are increasingly higher on the wall are associated with the 1/3, 2/3 and full lights on the control panel. The weakness is that solids and paper stick to the wall, short out the probe and give bad information. Gray and fresh tank probes are the same and, despite the lack of solids, condensation on the wall of the tank shorts them out.

Horst Miracle probes (now owned by Valterra and marketed as Valterra Horst Probes) address the problem by putting the probe farther out into the tank and, in the case of the black tank, they're shrouded on the top. The theory is the shroud prevents solids from shorting the probe and being farther out into the tank prevents wall condensation from doing the same. Some people report success; others scoff. I guess I'll find out.

The pic below shows the black tank probe with the shroud and the fresh tank probe without. You have to be sure the black tank probe is installed with the open side down. Otherwise, it acts as a scoop, not a shroud. The bolt on the outside has a flat spot which indicates which side is up.

I installed black tank probes in all tanks because they were cheaper at the time I bought them. Shrouded probes will work in fresh and gray tanks but probes without shrouds won't work in black tanks. They'll just catch all the toilet paper floating around.

Edit: changed pictures

Good explanation. I figured condensation induced errors. Now I know why they tend to show liquid present even when tank is empty sometimes. I have never had them erroneously show tank is empty when it is full, now I know why.

BriaBeck · 03-25-2021, 08:55 PM

Quote:

Originally Posted by Scrapper

My guess is beer.

Close!! It's really USED BEER!!!

phillyg · 03-26-2021, 09:28 AM

I'm smart enough to know that black tank tank probes never register properly, so I wouldn't do the job at all.

chriscowles · 03-26-2021, 10:06 AM

Quote:

Originally Posted by phillyg

I'm smart enough to know that black tank tank probes never register properly, so I wouldn't do the job at all.

Many users report that Horst probes work well. I'll let you know.

dankirk · 03-26-2021, 10:14 AM

If I'm ever an in a position to upgrade my tank monitoring system, I'll go with the SeeLevel system, and do away with probes. Just waiting for a time when I have to pull down the under belly for some other reason.

PhilFromMaine · 03-26-2021, 10:51 AM

Quote:

Originally Posted by dankirk

If I'm ever an in a position to upgrade my tank monitoring system, I'll go with the SeeLevel system, and do away with probes. Just waiting for a time when I have to pull down the under belly for some other reason.

Am I correct in assuming you are referring to the black fiber board that seals the guts of the underside of the floor? I have been looking at that lately and trying to figure our how that would come out and if I would ever be able to ever get is reattached properly.

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