Low water pressure on city water

[Steph and Dud B]

We rarely camp with hookups, but when we do, we have low water pressure at the faucets, even if the campground supplies high pressure. No problem when using the tank water and pump. It's been an issue since the trailer was new. We have an inline filter and pressure regulator on the hose but they are providing plenty of pressure entering the trailer, so there's a restriction in the trailer plumbing somewhere. Does incoming city water flow through the water pump, or is it plumbed in downstream from the pump discharge? If it goes through the pump, wondering if I can boost pressure with the pump and tank water.

Edited 7 hours ago by Steph and Dud B
Added info

[Tom and Doreen]

I have the same issue.  The plumbing diagram in my owners manual shows no intended restriction on the city line but my city water pressure is not as good as when I use the water pump.  ....You can activate the water pump and boost pressure when you're connected to city water however the water pump will pull water from the fresh water tank.  I often use it this way when I'm at a campground and would like more pressure in the shower. 

[Steph and Dud B]

@Tom and Doreen, that's what I figured about the pump. Thanks! 

[jd1923]

1 hour ago, Steph and Dud B said:

We rarely camp with hookups, but when we do, we have low water pressure at the faucets, even if the campground supplies high pressure. No problem when using the tank water and pump. It's been an issue since the trailer was new. We have an inline filter and pressure regulator on the hose but they are providing plenty of pressure entering the trailer, so there's a restriction in the trailer plumbing somewhere.

Yes, there is a restriction to both the incoming City Water and Fresh Water lines.

OTT plumbing diagrams only show the backflow prevention devices, labeled "check valves" in the plumbing diagrams. However, they also install flow restrictors. See basement picture rear of our hull. I can't be certain if this is true for all hulls, but take a look along the rear wall of your basement.

This slows down the City Water and slows down how long it takes to fill the Fresh Tank! It's been on my long list to remove both restrictors while cleaning the check valves, but like you, we use City Water about 1 in 10 days camping. We have also used the water pump to boost internal water flow when necessary.

What you're doing, using an actual pressure regulator vs. a flow restrictor, on the incoming City Water is the right way to do it, but given an inline restrictor, you're slowing down GPM 2 times. I have never used a pressure regulator knowing flow restrictors are built-in. I use a filter for desert water but don't bother with good mountain water. We do not drink water from our fresh tank anyway. I drain the Fresh Tank 1-2 times a year and bleach it every couple of years.

 

Edited 5 hours ago by jd1923

[Steph and Dud B]

Doesn't a restrictor just reduce flow? It wouldn't prevent a pressure buildup in the system when water isn't flowing. If that's the case, it won't protect your plumbing if connected to a high pressure source (unless you left a faucet open).

But that does describe the behavior perfectly. When we open a faucet, we initially get normal flow (from accumulated pressure), then the flow drops significantly. Also explains why we get normal pump pressure.

Edited 3 hours ago by Steph and Dud B
Added info.

[jd1923]

1 hour ago, Steph and Dud B said:

Doesn't a restrictor just reduce flow? It wouldn't prevent a pressure buildup in the system when water isn't flowing. If that's the case, it won't protect your plumbing if connected to a high pressure source (unless you left a faucet open).

Thermodynamics PVT (pressure-volume-temperature) was my worse subject of the engineering core! 🤣

They are dependent variables within a system. Most of the time, I just fill our Fresh Tank anyway. I've also upgraded to a REMCO US-made variable speed water pump, bumped up slightly to 65 PSI and 3.4 GPM ratings (OEM Mexico Shurflo was 55 PSI and 3.0 GPM).

PEX is rated at 100 PSI for hot water, 160 PSI cold. I don't worry so much given these numbers, but want decent pressure and flow on request.

When you get a chance, see if you have what's shown in my picture, both back-flow and restrictors on the two incoming water lines.