Bathroom sink draining to Black Water tank

Brakeman48 · 05-01-2016, 04:29 AM

I just sanitized the Fresh Water system in my 2016 Hurricane 35C. While flushing lines after clorinization with all faucets open the main (35C has two baths and separate holding tanks) bathroom sink started to back up. I had just emptied the Grey water tank. I checked the indicator panel which showed the Black water tank FULL. Emptied the Black water tank and then verified THE MAIN BATH SINK DRAINS INTO THE BLACK WATER TANK! Why would Thor do That???:

Marine By Choice · 05-01-2016, 06:33 AM

Mine does as well.

rivraton · 05-01-2016, 07:08 AM

Quote:

Originally Posted by Brakeman48

I just sanitized the Fresh Water system in my 2016 Hurricane 35C. While flushing lines after clorinization with all faucets open the main (35C has two baths and separate holding tanks) bathroom sink started to back up. I had just emptied the Grey water tank. I checked the indicator panel which showed the Black water tank FULL. Emptied the Black water tank and then verified THE MAIN BATH SINK DRAINS INTO THE BLACK WATER TANK! Why would Thor do That???:

Pretty much standard throughout the industry, I've been told that it's to increase the liquid to solid ratio in the black tank...

tenbear · 05-01-2016, 11:40 AM

Mine too.

I suspect that in my case, it simplifies the plumbing since the sink is close to the toilet. So it costs less.

Personally, I like it. The grey tank always fills faster than the black so diverting some of the waste water to the black tank increases the water to solid ratio and helps to delay the need to dump.

JamieGeek · 05-01-2016, 11:52 AM

Its the same on the Axis/Vegas units and its clearly shown on the plumbing diagrams for the units (you can request them from Thor). Thus its designed that way--not an error.

JRS950 · 05-01-2016, 12:36 PM

Same here on our class C. Not sure why, but it does by golly.

**EA37TS** · 05-01-2016, 01:01 PM

Quote:

Originally Posted by rivraton

Pretty much standard throughout the industry, I've been told that it's to increase the liquid to solid ratio in the black tank...

This is not standard throughout the industry and is done based on the configuration of individual coaches and the plumbing system design.

In my Challenger for instance only the toilet flows into the black tank. One 40 gallon grey tank handles the kitchen and bathroom sinks while the shower, outside kitchen sink and washer (if equipped) flow into the other 40 gallon grey tank. It is my understanding that on the 1 1/2 bath Challengers the rear bath toilet and sink flow into the rear 40 gallon tank, the front toilet into the black tanks and kitchen sink and shower into the front grey tank.

When I bought my Challenger neither the dealer not Thor sales rep could answer the question on how the coach was plumbed and that was when I requested the waste water diagrams to confirm my own testing.

Also on my prior class C (Forest River) toilet went to black and everything else to grey with the outdoor kitchen having a separate 12 gallon grey tank for the sink.

IMO, in some cases the plumbing design for the floorplan may be affected by the chassis since water does not always want to flow over axles, suspension systems etc...

MrPrincipal · 07-28-2016, 01:45 AM

We own a Thor ACE 2015, 30.1 we bought a eztow dolly to tow our car. The EZ tow calls for the 2" ball to be 14" to 16" inches from the ground. This is a great dolly except for going into a dip in the road such as driving into gas stations. Every time we drove into a dip, the bottom of the dolly dragged the street. It was so bad that it cut the lights cord on one dip. I had to re-wire it to have tail and brake lights on the trailer. The next time it broke off the emergency brake line. When I raised the trailer up to about 18" inches, the car kept moving away from the front bar, and had to be re-tighten on every stop.

JamieGeek · 07-28-2016, 02:01 AM

Quote:

Originally Posted by MrPrincipal

We own a Thor ACE 2015, 30.1 we bought a eztow dolly to tow our car. The EZ tow calls for the 2" ball to be 14" to 16" inches from the ground. This is a great dolly except for going into a dip in the road such as driving into gas stations. Every time we drove into a dip, the bottom of the dolly dragged the street. It was so bad that it cut the lights cord on one dip. I had to re-wire it to have tail and brake lights on the trailer. The next time it broke off the emergency brake line. When I raised the trailer up to about 18" inches, the car kept moving away from the front bar, and had to be re-tighten on every stop.

Interesting, our EZ tow dolly hasn't hit bottom at all, and we haven't dragged anything. Do you keep your toad in neutral while towing or leave it in park? I've found that leaving the car in neutral allows the wheels to rotate when the dolly rotates due to ramps/hills/dips/etc. and this keeps the straps tight. If I leave the car in park the wheels spin inside the straps and loosens them up adding wear to the straps.

In addition: This thread is about the bathroom sink draining into the black water tank, not really about toad issues.

Ag&Au · 07-28-2016, 05:00 AM

Our Airstream trailer was plumbed that way as is our new motor home. Others have pointed out cost benefits to the maker. I have always thought it was a benefit to me. In normal camping we have found our gray tank usually fills first by a whole bunch. I was glad to see some of it offloaded to the black tank.

Depending on the size and frequency of black tank deposits, your results may differ from ours.

Ken

MrPrincipal · 07-30-2016, 02:14 AM

I am sorry that I posted on the wrong thread. I am new to this forums. I appreciate all of the kind repremands that I received.

Sorry,

Mr. Principal

Bob Montgomery · 07-30-2016, 03:09 AM

Yes, it is supposed to go into the black water tank. The theory is it keeps the solids from being too solid and therefore plugging up your black water tank. It actually works pretty well. We have not had any blockage problems. At first we thought our black water tank was filling too quickly according to the gauges, but we were really trying to conserve water when flushing. When we started using more water when flushing, everything worked better and we found the gauges were now working better. You see using too little water gave false readings because the solids would "catch" on the probes... How big is your black water tank?

gauthig · 08-19-2016, 04:30 AM

I like the theory of the sink flowing into the black to increase solid/liquid ratio but also think Thor just wants to confuse us.

The front bathroom does just that, but the rear bathroom does not. Sink goes to grey and toilet to black. Not very consistent in the approach.

My problem is normal campsite hookups. I leave the grey open but close the black. This is a normal process and let's you run your black for a week before dumping. Also lets the enzyme type treatments chew up that solid stuff before dumping. But now I have to dump the front more often and use a lot more tank enzymes.

In my old Jamboree, sinks went to grey and toilets went to black. You always flushed for a few seconds to get water in.

Also, drink more water, naturally you should let out more liquids than solids.

JamieGeek · 08-19-2016, 11:39 AM

Quote:

Originally Posted by gauthig

I like the theory of the sink flowing into the black to increase solid/liquid ratio but also think Thor just wants to confuse us.

Its not just Thor: Many other motorhome manufacturers route the bathroom sink to the black tank.

Just make sure the sink faucet is off before leaving the camper...

Chance · 08-19-2016, 11:58 AM

Quote:

Originally Posted by gauthig

.....cut....

In my old Jamboree, sinks went to grey and toilets went to black. You always flushed for a few seconds to get water in.

....cut....

All design involves compromise one way or another. There is no perfect solution.

This type of operation, while simpler and more straight forward, adds extra water to total tank capacity. And if dry camping that extra flushing water will deplete the fresh water tank sooner too, so it would have to be larger as well.

Maybe on some very large motorhomes extra tank capacity and associated weight isn't as big a deal, whereas smaller and lighter motorhomes may benefit more from higher water utilization efficiency. In my opinion there is no one correct answer.

vkb · 08-19-2016, 02:07 PM

Quote:

Originally Posted by MrPrincipal

I am sorry that I posted on the wrong thread. I am new to this forums. I appreciate all of the kind repremands that I received.

Sorry,

Mr. Principal

You are good ! We all make that mistake from time to time...
we are here for you, whether or not you are on the correct thread !!

Happy Day !

Laco · 02-24-2017, 04:30 PM

Ours is plumbed that way as well. I hate it, don't need or want the manufactures help managing tanks, have been doing it for years, with only the pot draining into the black tank, before this motorhome. Some motorhomes, apparently even have the kitchen sink also draining into the black tank, and only the shower going to the grey. Dumb idea. I was told by Thor that my kitchen sink also drained into the black tank. I checked by opening the grey valve only, running hot water into the kitchen sink and got hot water out of the drain, fortunately.

**EA37TS** · 02-24-2017, 06:43 PM

Quote:

Originally Posted by Laco

Ours is plumbed that way as well. I hate it, don't need or want the manufactures help managing tanks, have been doing it for years, with only the pot draining into the black tank, before this motorhome. Some motorhomes, apparently even have the kitchen sink also draining into the black tank, and only the shower going to the grey. Dumb idea. I was told by Thor that my kitchen sink also drained into the black tank. I checked by opening the grey valve only, running hot water into the kitchen sink and got hot water out of the drain, fortunately.

You should contact Thor and ask them for the fresh and waste water diagrams for your coach. Those diagrams will show you what is plumbed into each tank.

On my Challenger the toilet only goes into the black tank. The other fixtures are plumbed into one of the two grey tanks depending on which side of the coach they are installed. Driver's side (kitchen and bathroom sinks) goes into the front grey tank and passenger's side (shower and outdoor kitchen) goes into the rear grey tank. The Thor diagrams are right on the money on this configuration.

Laco · 02-24-2017, 07:12 PM

Quote:

Originally Posted by dstankov

You should contact Thor and ask them for the fresh and waste water diagrams for your coach. Those diagrams will show you what is plumbed into each tank.

On my Challenger the toilet only goes into the black tank. The other fixtures are plumbed into one of the two grey tanks depending on which side of the coach they are installed. Driver's side (kitchen and bathroom sinks) goes into the front grey tank and passenger's side (shower and outdoor kitchen) goes into the rear grey tank. The Thor diagrams are right on the money on this configuration.

I have all the drawings from Thor, and believe it or not, it shows the kitchen sink going to the black tank. I talked to Thor and said the motorhome is virtually useless to me plumbed that way. I was told to check it, as often units are built differently than the drawings show. I checked it, discovered the kitchen actually goes to the grey tank, called Thor and asked for the 'as built' drawings vs the 'as designed' drawings provided. I was told the drawings I had was all they had!!!! So much for depending on their drawings!

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