Community Forums

RealNiceTent · 12-16-2022, 04:15 PM

Ok, a little back story. We here in Northern Nevada and temps dropped to freezing a few weeks ago, so we went to filling the water tank and using the pump instead of "City" water. OF course the bay heater also decided to go belly up again and I got up one morning to no water equaling no coffee. Grabbed a small 110 heater and set it up in the wet bay. I noticed a couple times over the last few weeks that if I was running water rinsing dishes at partial flow the pressure would surge and I could hear the pump surging.

So today I go to take a shower and just after I get my hair soaped up the pump starts surging badly, pressure dropping to half or less of normal, and of course scalding me as I'm trying to get the soap out of my hair. The batteries are off so I thought the converter just wasn't handling the load (furnace had been running). I got dried off a little, threw a robe on and went and turned on the batteries. I jumped back in the shower and tried again, more surging, but it cleared up mostly by the time I was done, however pressure seems low.
I figure it's pump replacement time, either it is worn out or was damaged by freezing. I went ahead and ordered a new pump, that's just the kind of year it's been. Either I need it or it will be a spare when I do need a pump.

Now the question I have for all of you is: what else should I look at before I plug in a new pump? I've given the electrical connections a glance and didn't see any that look like they have been overheated or any thing like that , and with four golf cart batteries voltage supple should not be an issue. The pump is a Shureflow and appears to have the pressure switch built in, and it looks nearly new, though I think it's the OE.

High Road Travelers · 12-16-2022, 06:21 PM

I run exclusively on my Shurflow pump and if I turn the bathroom faucet or shower on just partially the pump will surge, but will run smooth if I let enough water run through.
Every once in a while I have to adjust the Allen screw in the back of the pump so that it will run smooth without surging, bumping or not cutting off properly. I can't stand the surging, just isn't right. Also, you may should check the shower head screen/aerator/filter to see if it is clogged.
This is not really a lot of help, but if your pump is adjustable like mine, an adjustment might help.
Thanks,

bhammond1980 · 12-16-2022, 06:43 PM

I would replace the pump.

Flyer15015 · 12-16-2022, 07:21 PM

I dumped my Shurflow OEM pump last year. Heck it's only 17 years old.
I went with a Kolerflow pump and an accumulator in a much better location.
A year in on this $65.00 pump and I'm a happy camper.

Mike in Colorado

RealNiceTent · 12-16-2022, 09:00 PM

wog099, Wade thanks for the tip on the adjustment on the pump, I didn't know about that one. I really don't think it's a clogged screen, I have a filter after the pump, and use a carbon block filter on city water. I do however believe the pump is the original and 21 years old. New one is getting ordered, I should have a spare onboard anyhow.

Mr Hammond, replacement is my most likely action, but I'll still try to make the old one right and it will become the spare.

Mike aka Flyer15015 what is the flow rate on the Kolerflow? The Shureflow is supposed to be 3 GPM.

Ironically this pops up just in time for the project coming up first part of the week when I can work without getting frostbite. I've been putting off tearing out the wet bay to replace the dump valves, (black water won't seal) and do some other work in there including adding a small duct to the furnace for heating.

shootist · 12-16-2022, 11:56 PM

Surging under load is often the backflow valve in the pump. I don't think most are serviceable. Just learned this from an RV tech. So pressure up the system until the pump shuts down, pull the inlet from the tank and see if water flows out of the pump inlet. Pinch off the line or stick your thumb over it when pulled of course.

Persistent · 12-17-2022, 07:30 AM

Pumps, valves, and pipes freeze fast. Water expands when it freezes and bursts any enclosed spaces. Most likely you have freeze damage.

brandss · 12-18-2022, 06:44 AM

When I replaced our water pump I initially got an accumulator but the pump kept surging. I happened upon the below and decided to give it a try. It works great and does what it advertises, ultimately stopping the surge of the pump.

I probably don't need it, more of a nuisance with the sound and surging, but I do like it.

https://www.irvwpc.com/

RealNiceTent · 12-19-2022, 11:40 AM

shootist, my water pump is behind the control panel in the wet bay, if I pull the hose off the pump is getting replaced. I don't think it is a check valve problem though, the pump never runs without a demand, even if that demand is the shower dripping because I didn't turn the cold off like a gorilla (never drips on the wife).

Persistent, I am fully aware of the damages that can be caused when water freezes, I am also aware of the effects of pressure on the change of state from liquid to solid or gas on water. Pressure delays the change of state either way, this can keep the water in the line from freezing until you open the tap, the water instantly freezes, however because it has room to expand(the open tap) it doesn't do any damage.
Interestingly enough I turned up the heater in the wet bay a little bit and we don't seem to be having the problem, it's really a moot point however. New pump is ordered and on its way, and in a week we're headed where it's warmer. Las Vegas on the 28th &29th, and into Quartzsite/Salome on the 30th.
brandss, That is an interesting concept that is well proven in automotive fuel delivery, using phase width modulation to control pressure and volume. A little spendy, but I can see where it could do all of what it claims. Do you know if any coaches are using it in production? We're going to be in Quartzsite for the show, might be able to check it out there.

shootist · 12-19-2022, 05:24 PM

Check valve on the inlet side does not affect bleed off on the pressure side it's a diaphragm pump I am almost sure of that.
If the check valve fails it pumps some back towards the tank
And some forward. Disrupts the flow into the pump like it's losing
It's prime momentarily. I would have never expected one to act that way but it's what they do.

wopachop · 12-25-2022, 12:22 PM

If the pump has a clear screen on the inlet look for bubbles using a flashlight.
My pump has horrible water hammer when fresh tank gets low and sucks air.
Once fresh tank is full again my pump seems to have a hard time flushing out bubbles. I dont have my pump screwed down and will often rotate it around and tap it. Gets rid of some bubbles and the pump becomes much quieter.

I want to check the water inlet hose for holes. But scared to yank on it. It must be sealed where it enters the tank? If a rubber grommet that could be reuses. If the foam spray i wouldnt want to disrupt.

RealNiceTent · 12-27-2022, 12:32 AM

Quote:

Originally Posted by shootist

Check valve on the inlet side does not affect bleed off on the pressure side it's a diaphragm pump I am almost sure of that.
If the check valve fails it pumps some back towards the tank
And some forward. Disrupts the flow into the pump like it's losing
It's prime momentarily. I would have never expected one to act that way but it's what they do.

I think we had a variation of this problem caused by Ice in the check valve. I turned up the heater in the bay a notch and it hasn't acted up since. We were in single digits and teens at the time it happened. I di however receive my new Seaflow 3.5 gpm 45 psi pump Friday. If it hiccups again it will take me about 30 minutes to change it out.