Debris in the WH mixing valve... what are the chances?

[tommym1]

Originally Posted by RFP

Our Airstream is a 2014, and it has been a problem-free delight.

We have been noticing that there is probably 30% reduction in water flow when using hot water as compared to the cold water flow.

The aerators are perfectly clean, so I'm wondering if perhaps there is some 'crud' collected on the screen of the water heater mixing valve. I know that it's pretty easy to check, requiring only minor disassembly, but being a lazy lout (!), I thought that I would check with the brain trust.

As always, thanks for your help.

Robert

We had the same issue. Remove the mixing valve, soak in Lime Away or vinegar, reinstall and rock on.

[Toldfield]

We had the same issue in the hot water lines. It turned out to be minerals, or something, from the water heater. Now I flush the water heater tank at least twice a year and that seems to have reduced the problem. I remove the anode to do this and it gives me a chance to check to see if that needs to be replaced at the same time.

[A W Warn]

At home, I have a pump system that I built so that I can do an annual cleaning on my tankless WH with distilled vinegar. The pump continuously circulates vinegar through the water heater. This weak acid dissolves and removes all of the lime scale and debris created by mineral precipitation from the hard water.

In our Airstream trailers, the pump is already there, so all that would be needed are a few valves and fittings added into the existing plumbing so that a loop through the WH could be created. If I had this problematic mixing valve in my trailers I would give it some serious thought.

example of the kit I built
https://www.tanklessgeek.com/cleaning-kit/

[lsbrodsky]

Because sediment collects in the bottom, to get flow where you need it in the Atwood WH, you would need a fitting that replaces the drain plug, connecting to hose or piping, that returns flow to the water pump. This is no simple task. Your once through at home does not have a tank and recirculation is simple. I find, with a ball valve installed in place of the drain plug, with the water system pressurized, opening the ball valve just blows the junk out.
Larry

[Mike1997]

If you stay in campgrounds that have well water vs city/public system, beware of sand and debris getting into your plumbing system. My kitchen sink, bath sink, and shower head all had crud built up and sand. Once I got them cleaned out my black tank washer stopped working. It again was clogged up. Meantime I always use a filter on the water supply line and also found it getting clogged very fast, most filters last a month. Mine were only lasting about 2 weeks.

Now I am on another well system at a private residence and already finding rust/corrosion in the filter screen of the filter. This is mostly from irregular use but just another thing to watch for. Fortunately, no loss in water pressure yet.

[roamoore]

Airstream 23 FB. Mixing valve must be removed every 6 mos. and cleaned. Purchased a replacement valve and rotate it with valve in service. Problem is not with debris in water, (water filter at inlet). The problem is the heater “cooks” the water in the heater resulting in calcium buildup on the valve screen blocking hot water flow. Did not have this problem with previous trailers - but they may not have had a mixing ratio valve. The time and disassembly requirements is truly annoying. Stop by Harbor Freight and pick up their Pipe Tap & Die Set item 91395 you may need the 1/2-14 NPT tap to clean up tank threads. Sorry I don’t have my owners manual with my notes on a replacement cold water hose, (Lowe’s) and a few other items you might need in reassembly when things don’t go right. I believe a 1-1/6” socket may be required. A jug of white vinegar and a small brush with a container to microwave the vinegar in will be required. Enjoy DIY.

[Toldfield]

Yep, that's what I meant. This is the tool I use to hose out the water heater. It seems to work and makes a big mess in the driveway. It is a Camco water heater tank rinser.

[Adiredneck]

Since I spend summers camping in a campground with hard water from wells, I had noticed some "minerals" each fall when cleaning and flushing my HWH prior to winter. This Spring, using my bypass valve on the pump, I filled the HWH with white vinegar (took 6 gallons), and turned it on overnight. Ran straight hot water (vinegar) through all fixtures the next day, and then flushed it out and rinsed well with water. Everything clean as a whistle...

[Adiredneck]

Originally Posted by A W Warn

At home, I have a pump system that I built so that I can do an annual cleaning on my tankless WH with distilled vinegar. The pump continuously circulates vinegar through the water heater. This weak acid dissolves and removes all of the lime scale and debris created by mineral precipitation from the hard water.

In our Airstream trailers, the pump is already there, so all that would be needed are a few valves and fittings added into the existing plumbing so that a loop through the WH could be created. If I had this problematic mixing valve in my trailers I would give it some serious thought.

example of the kit I built
https://www.tanklessgeek.com/cleaning-kit/

Same principle and procedure works well for the tanked HWH models.



I had installed a Camco bypass valve just inboard of my fresh water tank (and before the pump) that allows me to siphon antifreeze throughout my system for winterization - just place siphon tube into gallon jugs of antifreeze and turn on each spigot. Did the same this Spring with gallon jugs of white vinegar and filled the HWH, and let it heat overnight. Cleaned out all calcium deposits, easy peasy...


Here is the bypass I use:


https://www.amazon.com/Camco-Permane.../dp/B0006JJ588

[SteveSueMac]

Now that’s a really interesting thought! I think this year before I winterize, I’ll use my winterizing kit to pump white vinegar throughout (not bypassing the WH) and flush that through the next day - then drain as usual and winterize with the pink stuff (bypassing the WH for that).

Did you dilute the vinegar at all or just draw it in straight from the bottle like the antifreeze?

[Adiredneck]

Originally Posted by SteveSueMac

Now that’s a really interesting thought! I think this year before I winterize, I’ll use my winterizing kit to pump white vinegar throughout (not bypassing the WH) and flush that through the next day - then drain as usual and winterize with the pink stuff (bypassing the WH for that).

Did you dilute the vinegar at all or just draw it in straight from the bottle like the antifreeze?

Since it was the first time I did this (previously just flushed it out with Camco WH nozzle), I pumped in the white vinegar at full strength, and then turned on the WH overnight. I then switched the bypass valve back to drawing from the FW tank and ran hot water through every spigot for about 5 mins. each - to let the vinegar dissolve any calcium that may have built up in the fixtures. After pumping the vinegar out of the WH I ran took out the bung and used my Camco nozzle to hose out the tank - no "white sand" appeared as in the past. Pumped clean water through the pipes and rinsed the system out good. Added benefit: the "vinegar douche" got rid of any residual anti-freeze taste in the pipes and fixtures!

[OTRA15]

Thanks for the details. My only concern would be the chemical reaction between the full-strength vinegar vs. the water heater's aluminum tank.

If the vinegar dissolved mineral deposits everywhere, what did it do to the inside of the aluminum tank?



Maybe just a microscopic reduction of the wall thinkness?

Seems like a good question to ask, anyway.

Thanks again,

Peter

PS -- As mentioned a long time ago, your signature is great!

"Hot meals, cold beer, dry bed & flush toilet - everything I look for in a wilderness experience..."

[dznf0g]

I have never heard of vinegar harming the tank. Have used it for many years. I simply made a 1" X 3' hose with a fitting on one end to go into the drain plug bung. I then use a funnel to pour 5 gallons of vinegar directly into the tank. I then bungee the hose up high to the awning arm, and run the heater through a couple heating and cooling cycles over a day or two. Then flush with the Camco wand mentioned above.

[tommym1]

Originally Posted by dznf0g

I have never heard of vinegar harming the tank. Have used it for many years. I simply made a 1" X 3' hose with a fitting on one end to go into the drain plug bung. I then use a funnel to pour 5 gallons of vinegar directly into the tank. I then bungee the hose up high to the awning arm, and run the heater through a couple heating and cooling cycles over a day or two. Then flush with the Camco wand mentioned above.

Sounds like a winner. I'd like to try this. Do you pour the vinegar in through the hose in the drain outside?

[dznf0g]

Originally Posted by tommym1

Sounds like a winner. I'd like to try this. Do you pour the vinegar in through the hose in the drain outside?

Yes, Just hold the hose and funnel higher than the tank level, and pour the vinegar down the hose and through the drain. I have the WH bypass valves to bypass in order to isolate the vinegar from the rest of the plumbing. Open the pressure relief valve to let air escape.

[tommym1]

Originally Posted by dznf0g

Yes, Just hold the hose and funnel higher than the tank level, and pour the vinegar down the hose and through the drain. I have the WH bypass valves to bypass in order to isolate the vinegar from the rest of the plumbing.

Thanks! Will do. Happy travels.