TrailManor Owner's Forum  

Go Back   TrailManor Owner's Forum > TrailManor Technical Discussions > Plumbing
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 02-01-2024, 12:41 PM   #1
Rob Culver
Senior Member
 
Join Date: Nov 2023
Posts: 75
Default Water pump pulsing

Hello all,
When I turn a faucet on in my TM to a low trickle the water pump will pulse, i.e. turn on and off about once per second. The water flow rate itself though does not pulse. As I turn the faucet knob increasing the flow rate it starts pulsing faster and faster. At about half the maximum flow rate it stops pulsing and the pump just stays on.

My question is: Is this normal? I cleaned out the filter and that didn't seem to change anything. The Shurflo 4008 manual for the pump suggests that one cause for pulsing (or rapid cycling as they call it), is that the shut off pressure valve is set to low.

Unfortunately, the location of this shut off pressure valve is very close to the underside of the sink and getting a 5/64ths allen wrench in to a very tight spot is quite difficult.

Has anyone succeeded in actually adjusting this valve or the bypass valve in order to eliminate pulsing?

Thanks in advance....
Rob Culver is offline   Reply With Quote
Old 02-01-2024, 04:02 PM   #2
Shane826
TrailManor Master
 
Shane826's Avatar
 
Join Date: Aug 2015
Location: Rochester, NY
Posts: 1,868
Default

Yeah it’s normal. It turns on and off based on pressure. Runs for a second, pressurizes the plumbing even though there’s a trickle at the faucet, shuts off, trickle depletes pressure, pump pulses back on, lather, rinse, repeat.

When you get to about half throttle at the faucet the pump can’t pressurize the plumbing as fast as the water is flowing out of the faucet so it just stays on constant until you close the faucet then the pump runs a couple seconds longer until the plumbing is pressurized and then the pump shuts off.
__________________
2007/21 TM 3326 (Pride of the Fleet)
2000 2720SL (Rebuild Project)
2002 2619 (Parts TM)
SMARTER THAN GOOGLE!
Shane826 is online now   Reply With Quote
Old 02-01-2024, 06:31 PM   #3
Rob Culver
Senior Member
 
Join Date: Nov 2023
Posts: 75
Default

Quote:
Originally Posted by Shane826 View Post
Yeah it’s normal. It turns on and off based on pressure. Runs for a second, pressurizes the plumbing even though there’s a trickle at the faucet, shuts off, trickle depletes pressure, pump pulses back on, lather, rinse, repeat.

When you get to about half throttle at the faucet the pump can’t pressurize the plumbing as fast as the water is flowing out of the faucet so it just stays on constant until you close the faucet then the pump runs a couple seconds longer until the plumbing is pressurized and then the pump shuts off.

Nice! Thanks Shane. I viewed the pulsing as a problem only if it was indicative of something going wrong. Glad to hear it's all good!
Rob Culver is offline   Reply With Quote
Old 02-01-2024, 06:50 PM   #4
Shane826
TrailManor Master
 
Shane826's Avatar
 
Join Date: Aug 2015
Location: Rochester, NY
Posts: 1,868
Default

If it keeps pulsing when the faucets are all shut off then you have a problem, you have a drippy plumbing issue causing a drop in pressure.
__________________
2007/21 TM 3326 (Pride of the Fleet)
2000 2720SL (Rebuild Project)
2002 2619 (Parts TM)
SMARTER THAN GOOGLE!
Shane826 is online now   Reply With Quote
Old 02-03-2024, 10:42 AM   #5
Wavery
TrailManor Master
 
Wavery's Avatar
 
Join Date: Jan 2022
Location: San Diego, California
Posts: 2,881
Default

If the pulsing bothers you, you can install an accumulator tank.

It can be installed anywhere in the waterline. It's a little cramped under the kitchen sink but it can be done.


"https://www.amazon.com/Akozon-Accumulator-Portable-Pressure-Waterproof/dp/B099K7SBGK/ref=sr_1_14_sspa?crid=2BT3G9TBWZ1HW&keywords=rv+ac cumulator+tank&qid=1706981948&sprefix=RV+Accumulat or+Tank%2Caps%2C189&sr=8-14-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1
__________________
TrailManor Elkmont
640W solar- 230AH LiFeP04 Battery
Wavery is online now   Reply With Quote
Old 02-03-2024, 03:27 PM   #6
Bill
Site Team
 
Bill's Avatar
 
Join Date: Feb 2003
Location: The mountains of Scottsdale, AZ, and the beaches of Maine
Posts: 10,147
Default

Wavery -

That is a good idea, but before embarking on it, take a look at this thread.

https://www.trailmanorowners.com/for...ht=accumulator

Note that this thread wobbles between fixing the pulsing and fixing the noise made by the pump when it is running. But apparently an accumulator that is small enough to fit under the sink is too small to do much good against the pulsing.

Bill
__________________
2020 2720QS (aka 2720SL)
2014 Ford F-150 4WD 5.0L
Bill's Tech Stuff album
Bill is offline   Reply With Quote
Old 02-03-2024, 04:26 PM   #7
Rob Culver
Senior Member
 
Join Date: Nov 2023
Posts: 75
Default

Quote:
Originally Posted by Bill View Post
Wavery -

That is a good idea, but before embarking on it, take a look at this thread.

https://www.trailmanorowners.com/for...ad.php?t=15220

Note that this thread wobbles between fixing the pulsing and fixing the noise made by the pump when it is running. But apparently an accumulator that is small enough to fit under the sink is too small to do much good against the pulsing.

Bill
Thanks Bill, (and Waverly), for pointing me to the right threads. Hard to find alot of things unless you use the exact right search words.
Rob Culver is offline   Reply With Quote
Old 02-14-2024, 10:27 AM   #8
Idaho Adventurer
Member
 
Join Date: Sep 2022
Posts: 13
Default

Quote:
Originally Posted by Rob Culver View Post
Hello all,

Has anyone succeeded in actually adjusting this valve or the bypass valve in order to eliminate pulsing?

Thanks in advance....
I had to make this adjustment to mine last year because I installed a new low flow shower head, and even with the water on all the way, the pump would pulse on and off resulting in hot cold pulsing. I can't remember exactly how I got to the adjustment screw on the pump, but you're right in that it was very difficult to get adjusted do to being so tight of access under there. However, adjusting it solved my problem.
Idaho Adventurer is offline   Reply With Quote
Old 02-14-2024, 10:38 AM   #9
Wavery
TrailManor Master
 
Wavery's Avatar
 
Join Date: Jan 2022
Location: San Diego, California
Posts: 2,881
Default

Another trick is to get a 25' garden hose and "T" one end into your system somewhere. Cap the other end. This will act just like an accumulator tank. You just have to figure out where to put it. It can even be stored under the trailer somewhere.
__________________
TrailManor Elkmont
640W solar- 230AH LiFeP04 Battery
Wavery is online now   Reply With Quote
Old 02-14-2024, 02:28 PM   #10
Bill
Site Team
 
Bill's Avatar
 
Join Date: Feb 2003
Location: The mountains of Scottsdale, AZ, and the beaches of Maine
Posts: 10,147
Default

That's a very inventive solution, Wayne. I like it. One thing, though. If the hose coil is permanently connected into the system (as a tank accumulator would be), and the coil is stashed below the level of the tee, drops of water will slowly migrate into the hose, "waterlogging" the hose/accumulator. Provision will likely need to be made to drain the hose every once in a while.

On the other hand, if the hose is permanently connected, and the coil is mounted above the level of the tee, or even stood up beside the connection, drops of water that enter the hose will drain back when the pressure is removed, and won't accumulate in the hose.

Or of course if you make the tee connection accessible, the hose coil could be connected and disconnected each time you set up and take down the trailer.

Bill
__________________
2020 2720QS (aka 2720SL)
2014 Ford F-150 4WD 5.0L
Bill's Tech Stuff album
Bill is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Water pump replacement info Jeff the marmot Plumbing 3 07-06-2014 04:09 PM
Water pump mod question Riwright Plumbing 3 11-16-2012 07:49 AM
Noisy water pump - making it quieter ShrimpBurrito Plumbing 35 05-22-2012 11:22 PM
SOLUTION: The ultimate fresh water transfer pump ShrimpBurrito Plumbing 38 03-01-2012 03:40 PM
Water leak at fresh water opening - HELP Bendy3 Plumbing 4 07-26-2007 10:37 PM


All times are GMT -6. The time now is 06:26 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 2022 Trailmanor Owners Page.