Water pump cycling causing uneven temps while showering

[JustinChase]

For some weird reason, now the kitchen sink is experiencing the pump cycling issue. It wasn't doing this until the fresh water tank got low, but even after filling, I'm seeing the cycling issue with the kitchen sink, the bathroom sink and the shower head. The toilet and the tub/bath faucet (without going thru the shower head) both keep the pump on without cycling.


I guess I just need to add a pressure tank to help, but it's weird the issue started after nearly a full tank of water didn't show the issue in the kitchen sink, but it continues even with another full tank.


I'm going to replace most/all of the pex in the RV soon enough, to eliminate the ridiculous amount of elbows they installed, so maybe that will help to allow enough pressure, but I suspect not.


I'm going to return the new shower head I bought, since the issue is now manifesting elsewhere. A different solution should hopefully take care of everything and I actually like my current shower head anyway.


Just wanted to update in case anyone sees this in the future.

[jarwiebe]

Originally Posted by Old-Biscuit

Shurflo 4008 is a Bypass Pump

Bypass diaphragm starts opening at 40#...and is fully open at 62#
IT recircs discharge back to suction side on Low Flow Demand (high pressure)

Pressure switch is set to turn pump off at 55# system pressure
Pressure switch is set to turn pump on at 40# system pressure

Here is a Down and Dirty pressure adjustments (should use pressure gauge on pump discharge but this procedure works)
https://lazydazearticles.blogspot.co.../Water%20Pumps



**Doubt pump really needs adjustments....cycling only occurs when using shower which is restricting flow

I have a bypass pump as well andhave adjusted it so it keeps running even at a low flow rate thus eliminating the pulsing. I know the manual says only authorized service techs to do the adjusting, but that has never stopped me from being a DIYer.

[Old-Biscuit]

It's a Bypass Pump....accumulator tank not recommended

Why don't you just do the adjustments in the Link before replacing, buying, adding anything????

Remove & clean Faucet aerators also

[JustinChase]

Originally Posted by Old-Biscuit

Why don't you just do the adjustments in the Link before replacing, buying, adding anything????

Remove & clean Faucet aerators also

Mainly because a $20 shower handheld was easier than anything else, and lowering the pressure at all is a bit of a last resort. I would prefer a much higher pressure than what I have already, so lowering just isn't appealing.


With that said, i'm not opposed to adjusting the pump as you suggest, but that just wasn't step 1 for me.


I'm going to replace the pex regardless, as it was very poorly done, and cuts into my storage space and the pipes are too close to several walls and floor so they vibrate annoyingly loudly, so that needs rectified no matter what.


if that doesn't resolve the pulsing, then adjusting the pump will be the next step.


Again, i appreciate your help, and will follow your suggestion if necessary.


thanks!

[Old-Biscuit]

Adjusting has NOTHING to do with Lowering the Pressure....just correcting the pumps bypass/pressure switches

Care on...........

[JustinChase]

Originally Posted by Old-Biscuit

Adjusting has NOTHING to do with Lowering the Pressure....just correcting the pumps bypass/pressure switches

Care on...........

Oh, then I misunderstood. Maybe I'll have a go at this tomorrow then.


thanks again

[LeisurePursuits]

My suggestion is to add a 2 gallon Shurflo accumulator tank and then adjust the bypass screw on the pump to effectively disable that feature. Works great for us. The pump only comes on occasionally. I can get about almost a gallon of water out of the sink before the pump kicks on. Can quietly flush the toilet at night, too. They are a little hard to find and somewhat pricey. Friends have used a steel expansion tank that is designed to be installed next to your home's water heater. Works the same as the Shurflow and is available at any home improvement store. Just tee it in after the water pump. That's about it.

[Old-Biscuit]

Or adjust the pump and let it work as designed............

[LeisurePursuits]

Originally Posted by Old-Biscuit

Or adjust the pump and let it work as designed............

What fun is that?

[JustinChase]

I tightened the pressure switch 1/4 turn and the shower no longer cycles, but the bathroom sink still does. I tightened another 1/4 turn and the bathroom sink no longer cycles as long as i turn either hot or cold on fully. if I turn the cold valve on less than 80% or so, it cycles, but above that, no more cycling.


Pump still comes on and shuts off instantly.


I tested and i can turn the kitchen sink faucet on less than 1/2 and no cycling.


Might fiddle with it more later, when I have someone inside to help, but for now, this is much improved.


Thank you again Old-Biscuit, you've been very helpful to me and my water issues!

[rgvtexan]

Old-Biscuit notice, only 13 more posts after I suggested dialing it in.
Thanks for your encouragement.

[Old-Biscuit]

Did you check/clean the faucet aerators on the kitchen/bath sinks?

[rgvtexan]

With your help he will get there. You have helped so many!

[JustinChase]

Originally Posted by Old-Biscuit

Did you check/clean the faucet aerators on the kitchen/bath sinks?

Yes, I removed the aerator on the kitchen sink actually, but both faucets are less than 3 months old, so they still looked new/clean.


I will have help tomorrow to help me test my adjustments in real time, to hopefully dial it in to give the best pressure possible, and allow the lowest flow possible without cycling the pump.


However, even it this is as good as it gets, I'm quite happy with it at this point.


thanks again!