No hot water pressure!

[Hibby]

After "summerizing" our 2012 Flying Cloud 30' I have little to no water pressure when turning any faucet to hot. The water heater is working. Is there an inline filter in the system that could be plugged? Cold water pressure is fine...

[jdalrymple]

Check the valves on the water heater bypass plumbing.

If they are correct, purge the air off the water heater by manually opening the pressure relief and allow the air to escape. Be careful when opening the relief valve, hot air and steam may spray out first.


Regards,

JD

[Hibby]

JD,

Thank you... I did try that, and the water tank does appear to be full and hot. However, still no change.

[dznf0g]

DO you have the big silver bypass valve with only one other hand valve? If so, take it apart....you'll find a strainer full of plumbers putty and other gunk.

[KeithC]

I have been camping in Airstreams for years and ran into this same problem for the first time last month. Very annoying.

I did the hotwater heater bypass valve check and drained the hotwater heater tank without result.

I fixed the problem by using the water pump to draw water from the freshwater tank and used that pressure to clear the cold and hot water lnes of air. It worked and I switched over to city water and everything worked fine. I still have no idea what caused the air lock problem. Hope this helps.

[pmclemore]

I have had the same problem and did everything I could to fix it. Almost bought a new one.

When I decamped and set up at the next site, it was fixed.

Pat

[Hibby]

I went out tonight and pulled the access panel off around the hot water heater. I tried banging on the check valve with a wrench (carefully) to no avail. I tried completely draining and refilling the hot water heater with the pressure valve open. I tried switching to pump instead of city water. I think my next step will be to raise and lower the front end to see if I can release any air bubbles. So far, no successes.

I do have plenty of cold water pressure. Here's a clue that someone might use to figure this out, if you're smarter than I am. When I turn the shower on COLD I have plenty of pressure, and if I leave that running and turn on another faucet COLD, I still have plenty of pressure. However, if I turn on another faucet HOT, the COLD water pressure in the shower drops immediately and significantly.

I'm stumped. Maybe it's time to buy a new Airstream. This one's two years old already...

[Bigventure]

Look at the back side of the hot water tank. Inside the RV. There are 3 to 5 vavles. The 2 on the floor are drains. the two lines that go to the tank should be open and the one that connect them should be closed. Open means the handle is in line with the pipe.

[A W Warn]

Corrosion (a white scale) most likely built up over the winter inside the water heater. This is normal when the water heater ages. If it did corrode, you will see a lot of crud in the fixture strainer screens after it has gotten into the pipes, then into the faucets and shower head. Take the shower head off and clean the strainer screen inside the end of the hose, then run hot water through the hose for a few minutes. Next, take the strainer screen off the outlet of both the kitchen and lavatory faucets and clean them, then flush hot water through them for a few minutes.

I've had to do this several times over the last 20 years.

If the above does not work you might try this: On my Safari, the valve on the outflow side of the water heater seems to let water pass better if it is not 100% open. Try closing the valves about 1/8 to 1/4 turn.

[lewster]

Look at the hot water outlet on the heater's tank (upper outlet) and see if you have a brass cylinder directly connected to the tank output. If you do, it is probably a check valve with a plastic insert. These are notorious for failing and not allowing the hot water to leave the tank, regardless of the street water pressure or water pump operation.

If you have one, you can simply remove it for now and still use your hot water tank, but I would replace it with an all brass check valve (that's a brass plunger and spring as well as a brass body) at your earliest convenience.

[Hibby]

AW Warn, those are both great thoughts, and I will try them tomorrow night. The trailer is relatively new, and I have no problem with cold water pressure, so I don't think it's scale, but I'll check to be sure. I will definitely try the water bypass valve in different positions.


Bigventure & Lewster, Here's a picture of my valve setup:



The yellow valve is the bypass, and I believe the larger metal cylinder at the top of the water heater is a mixer valve....

[Bigventure]

The by pass is OPEN! The vavle is in line with the pipe. Turn the yellow handle 90 degrees. This will close the bypass and give you hot water.

The cylinder is not a mixer vavle. I'm not sure what it is. My guess is a strainer or check vavle.

[Hibby]

Bigventure, the diagram on the water heater, although not visible, shows the bypass as "winterized" when it is perpendicular to the pipe and "in use" when in line with the pipe. Am I backwards on this?

[Bigventure]

Yes your backwards

[lewster]

Originally Posted by Hibby

AW Warn, those are both great thoughts, and I will try them tomorrow night. The trailer is relatively new, and I have no problem with cold water pressure, so I don't think it's scale, but I'll check to be sure. I will definitely try the water bypass valve in different positions.


Bigventure & Lewster, Here's a picture of my valve setup:

Attachment 212327

The yellow valve is the bypass, and I believe the larger metal cylinder at the top of the water heater is a mixer valve....

Hibby,

If you look at your water heater, you will see that it is an Atwood XT model. These units purposely over heat the water in the tank to about 160ºF and then mix or 'temper' it down by adding cold water to the extra hot water exiting the tank by the silver valve assembly that you have in your photo. You can see the cold water line entering the valve from the bottom. The now tempered hot water exits out the side.

I have seen many of these units with the same problem that you have. If you read your owner manual, you will see some fine print that details how you should flush that valve with vinegar on a regular basis to avoid calcification within the thermostat control section of the tempering valve. Problem is....I HAVE NEVER MET AN RV OWNER WHO DOES THIS.

The result is....you have to change the valve in order to get hot water again. You SHOULD NOT by-pass this valve by removing it, as 160ºF water WILL BURN YOU.

PM me if you need any other detailed information.

PS: With all due respect Bigventure, If you are not familiar with the operation and components of an Atwood XT model water heater, please do NOT provide misinformation that is based either on a guess or your experience with a standard water heater. His bypass is probably in the operational position and NOT backwards. The yellow valve at the bottom of the photo is a shut-off valve for the cold water supply to the water heater, NOT A BYPASS.

[Hibby]

Lewster, THANK YOU! I have not attempted to replace it yet but plan to do so as my next attempt (tonight if possible!).

With your explanation, I am relatively sure that this is the issue...

Thanks to all of you for your suggestions, and I will post an update as soon as I know for sure that the problem is resolved.

[Hibby]

Alright, I think I'm actually up and running again. Thought I had it fixed on the first try but didn't have the water temp set correctly.

I was able to remove a small back plastic insert (which was in a larger black plastic cap) with a knife blade. The insert covered a screw that held the larger black plastic cap in place. Once the screw and larger cap were removed, I was able to use a crescent wrench to turn the brass nut that determines temperature. Quite frankly, I just kept turning it in and out until I had warm water flowing again at the right temp. I'm not sure if the nut just needed adjustment or if adjusting broke some blockage loose, but it's working again.

I'm going to order a spare mixer valve just in case, since Camping World said it takes two weeks to get that part in... I'd rather spend the money and never have to use it than to take cold showers (although my wife has suggested that I should try it).

Thanks to all for your help!

[tommym1]

We just worked through this issue. Over the course of winter with the HW tank opened, bypassed, and DRY inside at the top where the bypass valve is located it dries out and the calcification makes the parts stick. In our case it self-corrected in a few days. Plan B was to remove it and soakn in Lime Away, which may happen next season. RV parks tend to have hard water. Best of luck and pls let us know how you make out.