Help me understand water pressure

[familytruckster4]

I think you may need to look at a problem with volume of water in the shower rather than pressure. My guess is that theres some sort of an obstruction in the lines going to that faucet. Maybe too many elbows or a kink or debris in a line or screen in the system. While it will eventually show pressure at the shower faucet, the flow is insufficient. Increasing the pressure at the inlet will overcome some of the inadequate flow but not solve the problem and eventually damage the rest of the system.

[Cate&Rob]

I think you may need to look at a problem with volume of water in the shower rather than pressure. My guess is that theres some sort of an obstruction in the lines going to that faucet. Maybe too many elbows or a kink or debris in a line or screen in the system. While it will eventually show pressure at the shower faucet, the flow is insufficient. Increasing the pressure at the inlet will overcome some of the inadequate flow but not solve the problem and eventually damage the rest of the system.

I would agree with your theory . . . except that the OP has stated that removing the pressure regulator solves the shower volume/pressure problem. I am quite sure (from his description) that the pressure regulator is where the flow restriction is located.

Rob

[bertschb]

Without an accumulator tank, static water pressure in an RV system will regularly climb beyond 100 psi.

OK, so 100+psi is normal. That's VERY good to know!

So the big question is - if the system can handle 100+psi, why would I bother with a pressure regulator that restricts flow/pressure and makes showers "worse"? I can't imagine municipal water supplies being over 125psi which is what I'm seeing inside my RV.

[bertschb]

I was just wondering if your shower "experience" was better with the pump than the regulator. ...I would guess that if there was a build up to 100 psi we would notice a huge shot of water when we first turn on a faucet which we have not seen. Does your RV sit with no water use for many hours, all day or a couple days?

Back when I was trying to figure out why our showers were so lousy (a year or two ago), I tried the water pump and it didn't help. Yes, at times when we open a faucet we get a "huge shot of water" for about 1-2 seconds. This happens a few times a day. I'm now realizing this is likely when static pressure is at 100+psi and it quickly drops to 40psi when the faucet is opened. Our RV rarely sits for more than a few hours without water use during the day.

[familytruckster4]

I would agree with your theory . . . except that the OP has stated that removing the pressure regulator solves the shower volume/pressure problem. I am quite sure (from his description) that the pressure regulator is where the flow restriction is located.

Rob

Yes, it could very well be that the regulator is faulty. My experience has been that they only last a few seasons at best.

[TedS]

Do a quick check to see what effect the pressure regulator has. With the pressure regulator installed, turn on the shower as you normally would and read the running water pressure. Pressure near the regulator setting, the regulator is probably not too restrictive. Pressure 10 to 20 psi less than the setting, the regulator is restricting flow. Open a couple faucets and see what happens to the pressure.
Repeat the test without the regulator and compare.

[bertschb]

Do a quick check to see what effect the pressure regulator has.

I just ran some tests and the results were inconclusive. Most likely because we're connected to my SIL's house which has a well. I watched the pressure while my wife was taking a shower and it varied from 25-45. It would slowly drop to 25 then go up to 45 as the well pump kicked on.

I did some test prior to her shower with and without the pressure regulator and the numbers were basically the same. High of around 45ish with or without the regulator with faucet closed and low of around 25ish with or without the regulator. I don't trust any of the numbers because we're on a well. We're leaving next week for a long road trip so I'll test the pressure as we visit different RV parks to see if I can get any reliable (and repeatable) results.

But, I still contend that if the static pressure in my RV can rise to 125psi at times, I have no need for a pressure regulator. All it does is make showers worse and does nothing to keep pressure inside the lines below whatever it's set at. The only scenario where a pressure regulator would help is if the water pressure at the post is higher than 125psi and I doubt it that ever happens.

[bertschb]

New record! I'm shooting for 140psi next.

[Jlawles2]

They do make various flow rate regulators. I ended up swapping over to a https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 which helped a little, but not much.

[familytruckster4]

Heres my 2 cents and where I would go with this. Its free advice and worth exactly what you spent on it

Replace the regulator (if you havent already and I missed that), I think the focus on that is distracting from the bigger issue

Evaluate the plumbing to the shower, I think you issue is one of inadequate flow. Increasing pressure will only slightly overcome a flow issue.
Look for excess elbows, possible blockages (debris or screens), kinks etc, and see if your line to the shower runs back to the source or is "Teed" or daisy chained off of another item like the sink or toilet.
I would start at the shower and trace the water lines back as far as possible. troubleshoot it from that aspect.

Best of luck.

[bertschb]

Replace the regulator (if you havent already and I missed that), I think the focus on that is distracting from the bigger issue

I appreciate the reply and advice.

My comments about poor shower experiences (in all three of our Grand Design 5th wheels not just our current one) has distracted from the purpose of my original post in this thread and I shouldn't have mentioned that.

The reason I started this thread was to get some help to understand why I'm seeing pressures over 125psi inside my RV and why we would use a pressure regulator to keep "outside" pressure at 50psi when we're regularly hitting over 125psi inside. My RV is currently handling 125psi with no leaks so I see no reason to mess around with a pressure regulator since it does NOT regulate pressure inside the RV.

From what others have shared here it sounds like the water heater is what is creating the huge pressure spikes. My current best guess is that I lost the air pocket in my water heater and that's what is driving the massive pressure rise. I drained some water from the tank yesterday to replace the air pocket and I'll be regularly checking the pressure inside the RV over the next several days. So far after 12 hours the max pressure has been 60psi with no pressure regulator.

If this massive pressure spike turns out to be caused by the loss of the air pocket in the water heater, I think Grand Design should start installing expansion tanks because I'm not the only Grand Design owner that sits in one spot for more than 30 days (which is apparently what causes the loss of the air pocket). There may be a lot of snowbirds sitting on ticking time bombs. When you add braided lines to the mix...

Sorry for all my long posts but installing a pressure gauge has opened my eyes and freaked me out in the process.

[Cate&Rob]

. . . installing a pressure gauge has opened my eyes and freaked me out in the process.

Hi Brian,

I wonder how many posts I have authored here and elsewhere, suggesting that owners install a water system pressure gauge to really see what is going on . . . rather than just guessing at it. Welcome to the group that can "see" what is going on inside their RV water system.

Rob

[bertschb]

I wonder how many posts I have authored here and elsewhere, suggesting that owners install a water system pressure gauge to really see what is going on . . . rather than just guessing at it. Welcome to the group that can "see" what is going on inside their RV water system.

Hi Rob

Your posts are why I finally got around to installing the pressure gauge. I would have done it sooner if I could have found the proper parts. It took HOURS of searching to finally find what I needed. Do you think adding a pressure tank will eliminate these pressure spikes I'm seeing? I don't ever want pressure in the lines in my RV to exceed ~60 psi.

[TedS]

Your solution to the loss of heater air space and accompany pressure rise is to install an accumulator. IPad one in other trailers and will install one in my current rig when I get home.

Your solution to low water flow is to eliminate the pressure regulator. I seldom use a regulator and have not had any resulting plumbing failures over 20 years of trailering.

[bertschb]

Well, it appears the massive pressure spikes are not caused by a lack of an air pocket in the water heater. I removed several gallons of water from the water heater last night. Just checked pressure inside the RV and it maxed out at 110psi at some point in the last couple hours. So much for that theory.