Low hot water pressure

GDawg

I need a little help please. I'm getting very low hot water pressure from my kitchen facet and shower. The water is hot, the cold water has very nice pressure, the hot and cold water mixing valve is all the way to the left, and I had my 320 a few degrees higher in the front as per other forum suggestions. When I turn on the cold water and mix at the sink or shower the pressure increases but hot water alone is about 1/3 of the cold just alone.

Any suggestions or advice would be appreciated.

2016 320 S

Thanks!

Greg

Sharon_is_SAM

We have had that problem.  I think it helped to adjust the mixing valve beyond your maximum setting.  It does not necessarily increase the water pressure, but, because the hot water is so much hotter, you end up mixing more cold water with the tap, and then the total flow is better.  See link below.

https://tab-rv.vanillacommunity.com/discussion/comment/117335#Comment_117335

GDawg

Thanks Sharon! I wondered if that was the case. I guess there isn't a  solution that will give me the outcome I would like but if I know that's just how it is I can live with it.

falcon1970

In a closed water system--such as your house or your TAB--the hot water pressure from the tap is controlled by the water pressure in the cold side of the system.  When you open a hot water faucet, the TAB water pump pushes cold water through the system (or tries to do so) and thus pushes hot water out of the faucet and replaces it with cold water in the water heater.  The water pressure should be the same from either a cold water faucet or a hot water faucet since it is the same pump in either case.  I would suspect there might be a restriction of some sort in your hot water line leaving the Alde tank.  Since you have low pressure in both the kitchen and the shower the restriction must be between the Alde and where the water line splits to run to each faucet.  The chances of two restrictions are pretty small but non-zero.  I doubt the lines are pinched or crushed since PEX is pretty robust but that is an easy first check.  Just trace the lines from one end to the other.  There might be debris in the hot water line.  Checking that will require disconnecting lines but a good place to check first would be the fitting where the two lines branch.  If there is debris it will tend to get hung up at the fittings.

GDawg

Very helpful! Can you give me an idea where they split? Is it in the  area where the Alde is located?

Thanks, Greg

GDawg

I took my flashlight out and found the split just as the hot line goes into the space under the shower. I've never worked on PEX or those weird little connectors or the copper looking things that secure the PEX to the connectors. Do they merely slide back or is there some sort of loosening that needs to happen?

Thanks again. 

ScottG

I suspect there is a resistance factor as well, since the hot water--which passes through the Alde and mixing valve first--needs to travel a lot further to get to the sink than the cold water.

I notice a pressure difference in mine, but not to the extent that you describe. There may be a blockage as @falcon1970 suggests.

However, those PEX connectors are permanent crimp fittings. You would need to remove and replace the crimp ring (using special tools) in order to open the line and inspect the fitting. Even if you had the tools, you may not have room to work with them in some of the tight spaces. Ergo, cutting up your plumbing just to inspect it should probably be a last resort.

If you do have to cut something, SharkBite makes push-on connectors that require no tools. I used one recently to fix a leaking fitting behind my toilet and so far it has held up.

GDawg

Thanks for the suggestions. I'm gung-ho about DYI and I typically eventually get things back together I have little knowledge about plumbing, electrical, HVAC, refrigeration, etc., i.e. everything having to do with my T@B. Having never owned a pickup or a trailer before this time last year it's been a rather steep learning curve. I continue to be impressed with the vast resource other T@B owners are through this Forum.  

Thanks

falcon1970

@GDawg
I have a 400 so I don't know about the 320 plumbing routing.  I agree with @ScottG that disassembly is the last resort--but I don't know how else to clear a blockage.  And there may or may not actually be a blockage in the line.  SharkBite products (there are some other similar brands) are very handy and easy to use. 
My rule when trying to fix something is to research how it was put together originally, research what tools and parts would be needed and how they are used, and pay close attention to how it comes apart.
I probably spend more time studying the thing than actually fixing it.  You can get a lot of information from the guys at Lowe's and Home Depot.  It is often very accurate--but not always!

4ncar

I won would also check the Alde bypass valve, and all valves just in case they are 1/2 turned.  Just a knee jerk thought, but could be an issue and a lot simpler to remedy then the line blockage...

falcon1970

@4ncar
An excellent and obvious point!  Always check the easy stuff first.

GDawg

I only checked to see if the valves were in the correct position. I should probably turn them on/off just in case there is something lodged in the valve itself.

Thanks

GDawg

I turned all the valves on and off several times and no difference in the hot water flow. I'm going to wait and see. When it's time to winterize I'll see if blowing the system out has any effect.

EPOD1

It looks like the last post was from 2019 and I did not want to start a new thread so I will start here.

2023 TAB 400

Shower has very little pressure and even less hot water pressure. I will look for a restrictor in the shower head, but I think the issue is somewhere else.

With the hot water pressure being low globally I am now curious about the hot water isolation valve that people are talking about. I truly wish they would give us some drawings or diagrams with our trailers.

I find the water pressure issue is greatest with city water but either way the shower head water pressure is truly insufficient.

manyman297

The fix in my case was cleaning the metal strainer in the mixing valve. The mixing valve itself is pretty easy to remove and I just let the entire valve sit in some diluted vinegar for maybe 30 minutes and then rinsed it. Mine had some obvious calcium deposits in the strainer so I knew that was the issue.

rfuss928

https://tab-rv.vanillacommunity.com/discussion/comment/222525#Comment_222525

The second time I had to take the valve out because of clogged screens I removed the screens completely. There is a simple spring clip on each side holding the screen in position. No hot water pressure problems since.

RTWCTS

We went through this conundrum last year. I ended up completely taking the mixing valve apart to clean it thoroughly. The valve on the hot water supply side was stuck in the closed position, apparently from deposits. I've recently been looking at portable water softeners. After dealing with the mixing valve, I worry about the long-term effects of (campground) hard water on the rest of the plumbing.

pthomas745

@EPOD1 you have the Thermostatic Mixing Valve in your 2023 trailer. The earlier comments on this 2019 thread involve an earlier (much more reliable) version of the mixing valve. The comments from the last couple of days involve the "New" Thermostatic Valve. Your first step is to find it down in the Alde compartment, which means taking the cushions and covers off that area and having a look.

You will find the mixing valve there, and, you should take a close look at the lay out near the Alde: you will find two "Yellow Valves" that you need to be familiar with in the future. Look for the "Thermostatic" mixing valve, brass fitting with a "red cap". If this valve is not properly adjusted, that "might" be the issue. The valve, as others discussed here, could have a clogged screen inside of it that is preventing the flow from being correct. In several cases, we have discovered the mixing valve was installed backwards! So, find the valve, take some pictures. Lots of threads about how to adjust the valve

New Thermostatic Mixing Valve.

This thread, and one other thread embedded in a comment, also describes what you are seeing and the possible fix if the issue is a "clogged screen".

Thermostatic Mixing Valve screen clog