Where's this brown water come from?

Just to add a little context to your question, is this new rig, or a new to you rig (used) or one you have had for a while with a new problem?

Do you use the same hose to flush the cleanout and fill the fresh?
Rust into the system? Most RV'S use pex so little chance of contamination. I would sanitize the system with a bleach mixture.

Just yesterday I anted to find why my water smelled bad, so I drained and flushed my HW tank to see if it was coming from there. Sure enough, the water came out from the tank drain plug brown and stinky. It seems accordingly to my HW tank Manf instructions I should have been doing this each year before storage. I used a cut-off washing machine hose to insert into the tank and hit it with full water pressure. Lots of "stuff" came out to my surprise.

jerryjay11 wrote:
Just yesterday I anted to find why my water smelled bad, so I drained and flushed my HW tank to see if it was coming from there. Sure enough, the water came out from the tank drain plug brown and stinky. It seems accordingly to my HW tank Manf instructions I should have been doing this each year before storage. I used a cut-off washing machine hose to insert into the tank and hit it with full water pressure. Lots of "stuff" came out to my surprise.

There should not be hot water flowing into the toilet.

TKW wrote:
After dumping the black tank at the camp site, I disconnected the city water and flush the tank through the sani-flush. I then asked DW to turn on the pump to add water & chemical into the toilet. She was shocked to see the water come from the tank was brown in color. We flushed and filled the FW tank with municipal water from home about a week ago and it was through a water filter. Would it turn bad within a week? There shouldn't be any chance of contamination from the sewage system. Any idea why is this happened ?

Possibly a mud wasp got into your water tank through an overflow line or something like that. Once you added water the mud nest dissolves and turns the water brown.
I would drain the tank. Catch some of the water in a clear container so you can tell if the water is dirty in the tank. If the water in the tank is clean you may have some rusting steel plumbed in your lines somewhere. Which shouldn't be there.

How old is the water filter?

Hi Tom, always seems to be something unexpected!!

So no water whatsoever in the tank from another source other than from home? Was the FW completely empty before filling or could there have any water sitting in it for a while? When was the last time you used the FW tank?

If you filled up at home on municipal water, Vancouver's water is quality stuff... It has low mineral content and the only thing in it should be chlorine and not a whole lot like in some places in the US. Won't have something like iron for ex. which is brownish and leaves stains in toilets but doesn't really color the water.

Is it a cloudy brownish color from turbidity level? Could the tank have had some fine silt/sediment sitting on the bottom before filling? If you hold a clear glass of water up to the light, what does it look like? Is it a more transparent chemical looking color?

What filter is it and how old? A sediment cartridge or something else? Did you sanitize your FW tank before filling at home? Does it have an odor? If you run a faucet, does the water stay the same consistent color? What does the filter screen at the pump look like? Before you drain the tank, perhaps save some in a bottle in case you want to investigate further at home?

Hard to do unless at home, but you could always install a filter after the pump

First thing I would want to figure out would be is the brown from the toilet spur of the the water system or in the entire system. Was it a short burst of brown water that turned clear? Or did the bowl fill with brown water? What about when you fill a glass of water at the sink, is it also brown? Also as suggested earlier what happens if you drain the fresh water tank, is the water from the tank brown?

Thank you all for the replies! There are lots of good suggestions here and I'm not going to response to individually.

To sum it up, my TT is a new-to-me unit on my 3rd season of ownership. Each year at the beginning of camping season, I sanitize the FW tank with chlorine overnight. Before each trip, I'd fill up with municipal water & drain before fill to the require amount for road use. This time out, we stayed at FHU site the whole trip so I only carried 1/2 tank of water for the overnight drive from BC to Bend, OR. I always separate my potable water hose from the sewer flush hose except I use a regular garden hose to fill my tank at home. I always fill my tank through a Camco KDF filter which I replace every season.

The water in the FW tank was about a week old. I drained the remaining (2-3 gal) this morning in a bucket and it was clear as can be.

The only possible cause I can think of is the sediment in my HW tank somehow get in the cold water supply. We had a plumbing failure a couple of nights before I dumped the BW tank. A fitting at the HW tank outlet came loose at midnight, (that's another story), and I had to shut off the water supply plus opening the low point drain to stop residual water from oozing out from the open hose. I also opened the HW tank pressure relief valve momentarily to ensure the system was no longer pressurized until I could attend to in the morning. I know for a fact that the check valve at the HW is not working properly. Could it be possible the sediment from HW tank got in the cold system while I cut off the park water supply? Water pressure at this CG was on the low side esp. with the pressure regulator I added to the system. It didn't stir up the sediment in the HW tank after the fitting was fixed but the on board pump pressure was high enough to stir it up. It was only a short burst of brown water and it didn't smell at all. It went away after a couple of flushes. Just my paranoid DW was concerned and suggested I might have to re-sanitize the system again.

It kind of sounds like whatever it was came through the park system, and any contamination is localized to the 1/2 inch PEX tubes. In the past I've had rusty looking water come out of a park tap that hadn't been used for a while.

Personally I would hook up at home and flush all the lines for a few minutes and then sanitize the whole system again. After that I wouldn't worry about it.