Normal for bathroom sink to be plumbed to black tank?

[Wdeertz]

On maiden voyage with 2016 Thor Hurricane 29m motor home. My tank gauges have been giving me weird readings so researched and read all the comments about the known inaccuracies of these gauges. During trying to measure the tank sizes I discovered my bathroom sink is plumbed into my black tank. I was under the impression that only the toilet went into the black tank.

This explains why my black tank was filling up quicker than I would expect from two peoples bodily functions. I suppose in some ways this setup is preferable as both black/grey tanks are 40 gallons and the grey tends to fill up faster.

Is the bathroom sink into the black tank normal?

[plasma800]

Lmgtfy

https://www.google.com/search?q=thor...obile&ie=UTF-8

[530ktm]

Originally Posted by Wdeertz

On maiden voyage with 2016 Thor Hurricane 29m motor home. My tank gauges have been giving me weird readings so researched and read all the comments about the known inaccuracies of these gauges. During trying to measure the tank sizes I discovered my bathroom sink is plumbed into my black tank. I was under the impression that only the toilet went into the black tank.

This explains why my black tank was filling up quicker than I would expect from two peoples bodily functions. I suppose in some ways this setup is preferable as both black/grey tanks are 40 gallons and the grey tends to fill up faster.

Is the bathroom sink into the black tank normal?

In many coaches this is normal.

[Wdeertz]

Originally Posted by plasma800

Lmgtfy

https://www.google.com/search?q=thor...obile&ie=UTF-8

Thanks for info, I guess I need to improve my google searches as everything has already been asked and is out there somewhere.

[jacwjames]

Only our toilet is plumbed to drain into the black tank. This is fine with me as we can better control levels knowing this.

When we are boon docking on an extended stay I will do some things to make the gray water tank last longer.

I will do dishes in a plastic tube and then pour this water down the toilet. Even if I am watching water consumption while doing this it doesn't take long to use 3-4 gallons of water.

Getting ready to take a shower I'll use a pot to catch the cold water while waiting on the hot water, probably another 1/2 of water into the gray tank if I don't do this. I'll then use the water I catch to make coffee of fill the dog water bowls.

Every little bit helps.

[Gary RVRoamer]

I would not say "normal", but it's not unusual either. Sometimes the RV maker does that for his convenience, since the black tank is always directly underneath the toilet (except for macerator type toilets). That may allow some additional flexability in gray tank location, and usually reduces the lubing costs for gray waste lines as well. And they will do anything to save a buck!

[isa]

It is quite normal for the sink water to be fed into the black water holding tank. Many manufacturers use this arrangement because people just don't use enough water when they flush there toilets. This ensures that the black water tank will have sufficient water in it when you dump.

[mel s]

Originally Posted by Wdeertz

On maiden voyage with 2016 Thor Hurricane 29m motor home. My tank gauges have been giving me weird readings so researched and read all the comments about the known inaccuracies of these gauges. During trying to measure the tank sizes I discovered my bathroom sink is plumbed into my black tank.
Is the bathroom sink into the black tank normal?

Wdeertz
It's "normal" on my '96 Safari.

BTW I owned my coach for 10 years, (and used it for over 100,000 miles). before I "discovered" that.

Mel
'96 Safari Sahara 3530

[Easyrider]

Certainly nothing wrong with toilet and sink plumbed to the same holding tank. Your stick built house all drains to the same sewer line. We use an extra add on valve on our dump valves to connect our grey and black water tanks together which allows us to use the space in the black tank for grey water. Saves us from having to dump the grey water when the black tank isn't even a quarter full.

[W4MBG]

Ours are plumbed together. 99 Winnebago Minnie.

[Gary RVRoamer]

Many manufacturers use this arrangement because people just don't use enough water when they flush there toilets. This ensures that the black water tank will have sufficient water in it when you dump.

LOL! That sounds a lot more impressive than "it's cheaper and faster to do it that way". It might even have a bit of truth to it. If only I believed any RV maker actually cared how well my black tank functions...

[Scarab0088]

Originally Posted by isa

It is quite normal for the sink water to be fed into the black water holding tank. Many manufacturers use this arrangement because people just don't use enough water when they flush their toilets. This ensures that the black water tank will have sufficient water in it when you dump.

isa is correct...

Several TMC models of Motorhomes (like the Outlaw) are Damon Legacy models.
Damon usually ran everything except the toilet to the grey tank...Thor changed that, for the reason described above.

This change required extra piping in some cases.

Knowing TMC's methodology, we (actually just me who does the dump) wish we could simply run the bathroom sink to add water to the black tank for improving black tank health...but since we have the Damon version (which also has no toilet side water-sprayer wand), it's either repeated/high water flushes or more frequent black tank washer/sprayer use in the service bay.

Serious boondockers would obviously want all the sinks going to the grey tank, but I believe for the great majority of RVers, extra water in the black tank is a good option.

The downside to any sink being plumbed to the black tank is that a DRY pee-trap (the goose-neck in the drain) runs the risk of black tank odor entering the coach...ya' gotta try to keep those pee-traps full of fresh water while in storage.

Safe travels

[Rich-n-Linda]

Our Mandalay is plumbed so the bathroom sink empties into the black tank.

[Mr_D]

Originally Posted by isa

It is quite normal for the sink water to be fed into the black water holding tank. Many manufacturers use this arrangement because people just don't use enough water when they flush there toilets. This ensures that the black water tank will have sufficient water in it when you dump.

Yep!!