Low water pressure in shower - old topic but what is the solution????

[bertschb]

All three of our Grand Design 5th wheels have had low water pressure in the shower. I've removed flow restrictors, replaced shower heads, etc but none of these things have fixed the issue. I've read many, many threads on this topic and I still don't understand why the shower has low pressure when all other fixtures in the RV are fine. I have an adjustable pressure regulator and 60psi at the post. Kitchen faucet blasts water. The one thing that makes no sense to me is the narrow little tube that the water passes through. This tube is just above the faucets and just below the hose that connects to the shower head. It is just over 1/4" OD. Even if all restrictors were removed, how can you get a "residential" flow of water through this tiny little tube???



I know others have replaced the shower head and I did that in our last Solitude but the results were not great. It did create a more forceful spray but with reduced water flow. If anybody has any ideas on how to actually get a true residential flow of "normal" pressure water from my shower, I'd love to hear how you did it. I personally think this teeny black tube is the culprit.

[Cate&Rob]

Hi Brian,

You might be mixing up "pressure" with "volume". With a small opening, the pressure in the line is maintained, but the volume of the high pressure spray in small. When you open up (or remove) the restriction, the flow volume goes up but the pressure drops. The onboard pump and many campground water sources are just not capable of high pressure at high volume. If you install a system water pressure gauge (as has been discussed on other threads) you will be able to see how the pressure drops when you remove the restriction orifice.

Rob

[bertschb]

Hi Rob

I understand pressure would drop if you remove a restriction. But that would happen at home as well and every home I've lived in has normal pressure/volume. Do I need to bypass 100% of the RV plumbing and run a line directly from the water source to the shower line? Having a normal shower experience is a big deal to my wife - which means it's becoming a big deal for me :-)

Do houses have 1/4" water lines at the shower?

[Cate&Rob]

Hi Brian,

To understand where the flow restriction is, you need the pressure gauge. For example, if the system pressure drops dramatically when you open the shower faucets, there is an upstream flow restriction. Maybe the Nautilus valves or the inlet water connection or maybe the supply can't keep up with the demand. If the system pressure holds when you open the shower faucets, the restriction at the shower hose connection could be the problem. Many residential showers are "water saver" which means that they have small orifice restrictions built in. Attached picture is of a residential laundry faucet aerator. Not a shower head, but pressure & flow very similar. Note the 1/8" flow restriction, but the house water system holds at its nominal 50 psi whether this faucet is open or closed.

Rob

[bertschb]

I've been to 15-20 different RV parks with 3 different Grand Design RV's and none of them have given us a residential shower experience. I'm not opposed to spending time trying to troubleshoot what I consider a problem but I doubt if all three of my 5th wheels had a problem with a plugged orifice, kinked water line or some other plumbing flaw. If it is a defect of some sort, I have bad luck!

Btw, our last house was built in 2019 and had all the latest energy saving ultra high efficiency features and it had a "normal" shower flow.

[Guest]

bertschb Brian,

I ran into this as well. When I unscrewed the shower hose from the faucet, I found that the small 1/8 inch port that was supposed to be closer to the middle (but still offset) of the outlet was in fact improperly drilled off to the side and mostly under the rubber seal. When the hose was tightened the gasket would expand and close off the small outlet port. The solution was to take a dremel with cone shaped bit and open up the hole toward the center of the outlet and flow and pressure has been satisfactory. May be worth a look.

Update: Went out and took a pic of my faucet to show you what I did. If this is the culprit, be careful not to drill too far center since the feed pipe as seen in your pick from the side is offset from the threaded part. After looking at this again, I may just open it up more since our water usage is relatively low.



Jim

[Cate&Rob]

bertschb
Hi Brian,

I am not disagreeing with your observations at all! Your house probably had an uninterrupted 3/4" feed line from a 10" water main pressurized to 60 psi (I'm just guessing at the sizes). That 3/4" line could run at full volume without noticeably reducing the pressure in the water main.

Now, lets consider the RV . . . likely a much smaller water main to the site to start with. A post faucet that is probably not a ball valve, so considerable restriction here. A 1/2" hose to an inlet back flow preventer, so considerably more restriction here. Probably an inline filter so more restriction here. Now, a network of water panel control valves with 1/4" internal passages in each, so more restriction here. Lets not forget the back check valve on the water heater outlet.

In my RV system, I start with a 50psi regulator. Static pressure on the system gauge is 50 psi. Open the kitchen faucets and pressure drops to 30 psi. Open the outside taps with spray nozzle attached and pressure drops to to 20 psi. Take the spray nozzle off and open the valves and pressure drops to barely measurable. (I have never actually observed pressure drop with just the shower, but it would likely be somewhere between 20 & 30 psi.) My pressure transitions are actually more complicated than this because of my accumulator tank, but lets leave that out of the discussion for now .

I know that folks are likely tired of me saying this, but . . . a $10 pressure gauge and $5 worth of fittings will answer most of your water flow questions.

Rob

[bertschb]

bertschbNow, lets consider the RV . . . likely a much smaller water main to the site to start with. A post faucet that is probably not a ball valve, so considerable restriction here. A 1/2" hose to an inlet back flow preventer, so considerably more restriction here. Probably an inline filter so more restriction here. Now, a network of water panel control valves with 1/4" internal passages in each, so more restriction here. Lets not forget the back check valve on the water heater outlet.

^^I think this answers my question Rob.

The design of the RV water system as well as potential water supply limitations are the problem. I can probably bypass the RV water system but I can't improve the water supply at the post. It's disappointing but at least I have a better understanding now of what the problem is. I won't take residential showers for granted any longer :-)

As always, thanks for your help!

[howson]

bertschb (Brian),
You may remember way back when I did quite a bit of research to figure out where (and why) I had low water pressure (or low flow?--I'm probably driving Rob nuts!). This is not meant to counter Rob's advice or suggestions--just proposing an alternative approach.

The simple setup shown in the picture allowed me to measure the amount of water over a given amount of time from each water source in the camper. (The shower head should unscrew to allow you to test that, too.)

The point, obviously, is to quantify the water from each outlet over a set time. (I think it was 1 minute when I did my research.) If the quantities are the same (or close), the problem is likely at the water supply source. In that case, running the pump (with water in your fresh water tank) while taking a shower *should* solve the problem. If the amount of water measured is significantly less from the shower (than either sink) than there's a specific problem with the shower plumbing. "Fixing" the source or running off the pump won't help in this instance.



Isn't plumbing just the best?

[Guest]

bertschb;n21106]

^^I think this answers my question Rob.

The design of the RV water system as well as potential water supply limitations are the problem. I can probably bypass the RV water system but I can't improve the water supply at the post. It's disappointing but at least I have a better understanding now of what the problem is. I won't take residential showers for granted any longer :-)

As always, thanks for your help!
[/QUOTE]

bertschb Brian,

Have you unscrewed your shower hose from the faucet and looked at the faucet opening? Not sure you have seen this but opening up the orifice cured my issue of a low flow rate to the shower head. I would check this before re-plumbing the camper.

Jim

[Cate&Rob]

howson
Howard, the "problem" with your water volume measurement technique is that you will get the highest volume at the lowest pressure. Open flow (no back pressure) is the least restrictive and will result in the most water . . . but, not particularly useful for shower water pressure.

bertschb
Brian, the solution to your dilemma is to invest in a much more capable on-board water pump. (the OE pumps are the "least expensive" available). Think about a pressure washer pump (obviously not what I am suggesting ) but, you can have 2000 psi out of that shower head if you wanted to! Something in the middle would be about right. There are a number of alternatives in the marine world. Something with 3 times the volume capacity at 50 psi should do nicely. This would mean switching to on-board pump and tank water for showers . . . should not be a big problem.

Rob

[bertschb]

Have you unscrewed your shower hose from the faucet and looked at the faucet opening? Not sure you have seen this but opening up the orifice cured my issue of a low flow rate to the shower head.

Hi Jim

I did this on the last two 5th wheels but not this most recent one.

[bertschb]

[USER="10"]Brian, the solution to your dilemma is to invest in a much more capable on-board water pump...This would mean switching to on-board pump and tank water for showers

I just did another experiment. I put 15 gallons of water in the fresh water tank and tried using the water pump as some have suggested this really helps. No dice for me. I didn't do any formal measurements. Just watched where the flow of water hit in the shower compared to city. Seemed about the same to me.

As far as switching between city and tank water, do I need to remove pressure from the lines by opening up faucets prior to switching modes on the water panel? If so, it's kind of a hassle. You have to go outside and shut the water off at the post then go back inside and release pressure from a faucet, then go back outside and switch the control valves on the Nautilus panel to tank water then turn the water supply back on at the post. Not sure I want to do that at 6:00AM with no coffee.

[howson]

howson
Howard, the "problem" with your water volume measurement technique is that you will get the highest volume at the lowest pressure.

I realize pressure can increase (or decrease) at the output without changing the pressure at the source--anyone who's ever clamped down on the end of a hose with their thumb knows what happens in that instance. The restriction at the output probably does decrease overall output. That makes sense. No different than electricity (I think). Put a 10 meg ohm resistor in line with a 12v battery and you'll get very low current flow. Swap it out for a 10 ohm resistor and the current will be very high.

However, given the same plumbing, an increase in pressure or decrease in the flow restriction (from the source to before the faucet, not at the faucet) must result in a higher volume (flow) from the output of the faucet--right? The suggestion to replace the water pump is essentially the same thing, isn't it? Installing a device capable of higher pressure at the source ("2000 psi") resulting in more flow? (I realize you were being sarcastic with the 2000 psi.)

Measuring how much water came out of the faucet over time provided a numerical reference for comparison. It would not matter if there was 80 psi on the gauge at the Nautilus panel if all I got was a trickle from the faucet. The method I used was definitely "shadetree plumbing", but I was able to compare my home's faucet output to the camper faucet output and knew there was an issue by the numbers. What I could "feel" was wrong in the camper I found a way to document. When I found the fix (you may remember the debacle with the restrictor) I was able to definitively compare the result numerically in addition to the kitchen faucet's output "feeling better".

[Canyonlight]

This is all quite interesting. Our stock water pump, plumbing, shower head, etc. has plenty of flow on both city water and using the pump. In fact even Carol turns down both hot and cold control handles when washing her hair as does our daughter who has long blonde hair.

I do not recall many folks having issues like Brian is sharing especially when they have replaced the shower head with the Oxygenics version. Sure there are a few but trying to compare an RV/camper (which is designed to both be like a home but yet conservative in utilities use) seems to be a tough go especially if one has a better than average home shower system.

Brian bertschb - think Navy shower.........maybe those of us who grew up with this (my father was a Navy man) are just easy too please with not only this issue but things in general. I do hope you find a solution because keeping mama happy is quite important !

Dan