Hot Water Pressure Low

[jimbo1087]

In our 2012 Flying Cloud (30 ft) we are experiencing low hot water pressure. The cold water pressure is very good. I flushed the tank and there was some sediment in the tank. Temp is warm when using the electrical switch and hot using propane.

I'm thinking that the thermal sensors are going out, but I thinking that shouldn't effect the pressure.

Any thoughts would be helpful. Thanks in advance for any suggestions.

[dbj216]

Can we assume the hot water pressure is low at both the galley and bath and shower faucets? And we assume the hot side water pressure is low even if the water heater is turned off.

So there must be a blockage in the hot water "main" line that exits the water heater and typically runs the length of the trailer. Some folks run this line in "red" PEX, and the cold lines in "blue" PEX like I did.

I'd first check the bypass valves to ensure the one on the hot line is fully open. I'd probably close it, and open it again with a hot faucet open as that might clear some debris. And I'd check the one on the cold water into the water heater for the same way for the same reason. Any restriction in these valves could cause low flow on the hot side.

David

[J. Morgan]

http://www.airforums.com/forums/showthread.php?t=121902

[dbj216]

Thanks Mr Morgan, I did not know new style hot water heaters had a mixing valve on hot water coming out. As stated in your link, this a solution looking for a problem. I would not want one on my trailer.

David

[jimbo1087]

dbj216;

Thanks for the picture (Worth a 1000 words). I was wondering how to run the lines. Hot water pressure is low in the bathroom, kitchen and shower. After reading all of the comments I'll be removing the valve.

Also a thanks to J. Morgan for the suggestion of removing the valve.

[Wayward]

I am not familiar with what Airstream has put in the newer models, but I have a mixing valve at home.

A mixing valve can serve a useful purpose by allowing a much higher hot water temperature than would normally be safe.

6 gal of 200 degree water goes a longer way than 6 gal of 120 degree water.

[jimbo1087]

There have been several comments raising concerns about safety issues of water temps between 170 to 200. These are very validate concerns. Again I really appreciate all of the comments.

[J. Morgan]

In the old days it was possible to turn the water temps down. Maybe this cant be done with the newer heaters.

[lewster]

Thermostats in the more recent RV water heaters made by Atwood and Suburban use fixed temperature thermostats available in either 130ºF or 140ºF settings. I have seen an aftermarket 'adjustable' replacement, but it is not Ul or CE approved and will void your warranty, not to mention putting your personal safety at risk.

[J. Morgan]

Well regardless,,, if it was me,, when I would have gotten a price of two hundred bones for a valve that only lasted a few years I would pull it out.

That price is a rip off. As a mater of principle, the mixer would thereafter be on my shower valve and only on my shower valve.

[AtomicNo13]

Oh yes, most modern faucets have a mix device which also limits the temp giving some additional safety.

[dbj216]

I recall from my factory days that I could place my hand on and hold a 120 degree temp item. I could touch, but didn't want to hold, a 140 degree item. 140 degrees hot was my upper limit. I believe factory safety regulations require personal protective equipment for temps above 120 degrees.

140 degree water is hot, and will scald the skin some. I think the water heater temps of 140 deg is safe.

David