low pressure from hot water

[rbs]

left IL currently in LA. Flushed the antifreeze from the system, filled hot water tank, turned on hot water heater. We have great pressure everywhere on the cold water side, but the hot water side is very low pressure. We winterized using our normal procedure, blowing the lines, pumping antifreeze thru the entire system, bypassing the hot water heater. This is on our 2015 Classic by the way, which has one valve to bypass the hot water heater. I'm thinking we have a partial blockage some where, possibly the shut off valve, but wondered if anyone else has experienced the same thing, and what they found to be the cause?
Thanks

[Jim Flower]

Hi rbs. I had a similar experience and the fix, although effective, was not pretty. The valve was faulty so it was replaced with an alternative system since the factory system has, apparently been problematic. They eliminated the single valve, installed a traditional by pass system complete with the appropriate gate valves. A pressure relief valve with an exterior discharge was also installed in the hot out line. I have been semi pleased with the fix. The new pressure relief valve also malfunctioned and I replaced it with a new one and this procedure was much more simple than the original malfunction to the single factory valve. Bottom line, giant pain, especial while on the road since it required a dealer to tackle the original issue. Jim

[rbs]

Looks like my issue is the mixing valve, a problem that Atwood is familiar with. Since we are still under warranty will have the valve replaced, and do some more research on alternatives down the road, looks like there might be mixing valves that would be more maintenance friendly.

[HowieE]

You use the term Low Pressure. There is a difference between pressure and flow volume. if when you first turn on a hot water faucet there is momentary pressure and then the flow drops off that is an indication of a blockage as pressure will equalize if there is no flow.

If the mixing valve is after the output of the heater it will tend to get clogged, when you refill the heater in the spring, with the scale that is always on the bottom of the heater. To prevent this you should fill the heater with a very low flow rate in order not to stir up this sediment.

[CDONA]

I had my hot water flow down to a trickle over my summers travels. I tried draining the tank, didn't get much solids flowing out. Filled and drained a couple more times, no fix. I read the instructions about the drain will not empty the tank, and needs a small diameter external hose to stir up and purge the tank. And the issue of the mixing chamber may have a screen that clogs when the sediment is stirred up on a fast flow refill with the tap open to purge the air. The manual wants the mixing chamber removed to clean. What I did was hammer lightly on the mixing chamber to dislodge the sediment as to settle back to the bottom of the tank.
I did get my hot water flow back. I also made a 1/4" flusher hose that I haven't used yet.

[drairstream]

there is a thread about washer coming off one of the bypass valves. It fixed me. just take the valve out, feel inside for the washer. bet u find it.

[joemikeb]

Originally Posted by rbs

Looks like my issue is the mixing valve, a problem that Atwood is familiar with. Since we are still under warranty will have the valve replaced, and do some more research on alternatives down the road, looks like there might be mixing valves that would be more maintenance friendly.

I had the same mixing valve problem on my Interstate and the dealer wound up replacing the whole hot water heater under warranty. Hopefully Atwood has engineered a fix in the new one.

[rbs]

Made arrangements to have our water heater issue looked at with Gauthier's RV in Lafayette, LA, an Atwood Service Center. We had a few days before we would be at Palmetto Island and continued to use the hot water. We noticed that the flow was gradually increasing until finally we were confident that it was acting normal. Not certain how it "fixed" itself, but was able to cancel the appointment, although I probably will carry a spare mixing valve. I will add that Gauthier's was really a joy to work with, they made a spot available for me and made sure the right valve was on hand.

[overlander63]

I've removed and partially disassembled the mixing valve, and found the little check valve thingy had become stuck partway open. A tap with a hammer unstuck it, and I re-assembled the unit. It worked well after that. If the trailer is no longer under warranty, I would try this, if still under warranty, let a dealer handle it.