Water pump cycles every couple seconds

[WingRider]

In our '21 240RL we typically use the city water connection, however sub-freezing weather tonight caused us to disconnect and draw from the fresh water tank. When I turned on the water pump, it ran for just a second, quit for a second or two, then repeated until I turned it off. If I turn on the pump and open a faucet, the pump runs as expected with good flow/pressure.

My first thought was a leak. I loosened the basement paneling by the Nautilus panel so I could see the pump and the water lines back there. All was dry with no signs of a leak.

Then I checked the valve settings on the Nautilus panel to make sure I had it in the dry-camping mode. All good there.

When i filled the fresh tank I changed the valves on the Nautilus panel from city water to the power fill position. I did not turn off the water at the post, nor did I release pressure in the system before doing so. Is it possible i damaged a check valve by doing this?

We use the pump very little, but we have used it in the past year without issue, until today.

Anybody have any clues?

[Scott'n'Wendy]

That is the classic symptom of a leak. Looking just by the nautilus panel isn't really verifying there are no leaks. Sinks, water heater, outdoor shower are a few more places to check.

[TedS]

I doubt you damaged the inlet check valve. Turning the valve to fill is how I alway release the hose pressure before disconnecting it and the check valve has never failed.
There may be a faucet not quite 'off'. There may be a little debris in the pump head letting water leak back to the tank. Running the pump would help clear it.

[howson]

Anybody have any clues?

If there was a leak in the camper (other than at the pump) why wouldn't it also leak on city water pressure? Maybe it is a leak and it's so small (or hidden) the leak hasn't shown itself (evidence of water damage, mold, etc)?

Could it be as simple as there's air in the lines due to switching over to the internal pump? (Air will compress, water will not.)

A way to check if there's an internal water leak in the camper is to connect city water with a pressure gauge inline installed in the water lines of the camper (has to be past the check valve in the city water connection). (A pressure gauge in the system is the resident guru, Cate&Rob , advocates for frequently.) While monitoring the gauge, shut off the external city water. Does it drop or stay constant? If it drops--there's a leak as suggested by Scott'n'Wendy . If the pressure is constant, the problem could be pump-related or could even be something in the Nautilus panel (though not as likely IMHO).

If it's the pump it could be the internal valve in the pump letting water go back to the water tank so you'd never see a water leak anywhere.

Another idea (mind is going in several directions...hang with me). Not sure if this will work...never tried it myself...but it won't hurt anything.

With the Nautilus panel set to dry camping, turn on the pump until it stops and then turn off the pump. Wait @ 5 minutes and then open a cold water faucet--any pressure?

Now do the exact same experiment with the Nautilus set on City Water with city water applied to the camper for a moment or two (and then shut off the city water pressure from the source). Any pressure from the faucet when it is opened after 5 minutes? (Make sure all air is out of the faucet's lines when doing both experiments.)

If both experiments result in no pressure...there's a leak somewhere in the camper. If the city water experiment has pressure but the pump test does not, the issue is likely with the pump.

I'd try this on mine just to see...but it's freezing here today and the camper is prepped accordingly, so no water tests today!

Howard

[Cate&Rob]

There has to be a water leak somewhere. If this is not visible under the trailer, this could be a drip leak from a faucet going into a grey tank, or the toilet going into the black tank or the outside shower hose going on to the ground. If the check valve in the onboard pump were leaking, city water pressure would eventually fill the onboard water tank and then come out the tank overflow pipe. As Howard references, a system water pressure gauge will answer the questions. As a temporary installation, this gauge can be connected to the cold water low point drain.

Rob

[WingRider]

Just a note to update this situation.

We used the pump for the last 36 hours to wash, flush, and the like. Sometimes the pump would 'rest' for up to 3 seconds before it ran again, but it never shut off and stayed off. We just turned it on and off as needed so it wasn't running all the time...

Now that the weather has warmed up again, I did a more thorough inspection of the water system in the rig, and again found no evidence of a leak anywhere. Given that the pump loses pressure in just a few seconds, that would seem to indicate a rather substantial leak, and I simply don't see any evidence of it external to the pump.

Then I took Howard's suggestion and, after it got warm enough this morning to reconnect to the city water, I performed the test he described.

I turned on the water pump until it shut itself off, then shut off the power to it and set a timer for 10 minutes. When time was up, I opened the kitchen water faucet (farthest from the pump) and it drained 4 oz. of water before it stopped flowing.

Then I reconnected to city water, ran faucets to flush all the air out of the system, then shut off the water at the pole and waited another 10 minutes. When time was again up, I opened the kitchen faucet. This time I drained 10 oz. of water out before the flow stopped.

This all seems to indicate a bad check valve at the pump itself, no?

It also occured to me that I did not run the pump to clear water from it when I winterized the rig last fall (I use compressed air to drain lines...). It's entirely possible that some left over water froze in there and did some damage to it... When I get a chance I'll remove it and see if that's the case.

Brian

[Jlawles2]

WingRider You may find when inspecting it that something is just out of place. Hope that's the case and nothing is damaged.

[Yoda]

Just a note to update this situation.

We used the pump for the last 36 hours to wash, flush, and the like. Sometimes the pump would 'rest' for up to 3 seconds before it ran again, but it never shut off and stayed off. We just turned it on and off as needed so it wasn't running all the time...

Now that the weather has warmed up again, I did a more thorough inspection of the water system in the rig, and again found no evidence of a leak anywhere. Given that the pump loses pressure in just a few seconds, that would seem to indicate a rather substantial leak, and I simply don't see any evidence of it external to the pump.

Then I took Howard's suggestion and, after it got warm enough this morning to reconnect to the city water, I performed the test he described.

I turned on the water pump until it shut itself off, then shut off the power to it and set a timer for 10 minutes. When time was up, I opened the kitchen water faucet (farthest from the pump) and it drained 4 oz. of water before it stopped flowing.

Then I reconnected to city water, ran faucets to flush all the air out of the system, then shut off the water at the pole and waited another 10 minutes. When time was again up, I opened the kitchen faucet. This time I drained 10 oz. of water out before the flow stopped.

This all seems to indicate a bad check valve at the pump itself, no?

It also occured to me that I did not run the pump to clear water from it when I winterized the rig last fall (I use compressed air to drain lines...). It's entirely possible that some left over water froze in there and did some damage to it... When I get a chance I'll remove it and see if that's the case.

Brian

When your looking at the pump take a close look at the intake filter on the pump intake. Check for cracks. If it is cracked the pump will pull air causing your symptoms. If the check valve is bad you can install one inline on the pump outlet, instead of replacing the entire pump. Just some thoughts.

[TedS]

The pump should be repairable by replacing the pump head. A freeze may have cracked the pump head or inlet filter bowl.

You can check the pump for leakage. Disconnect the intake(suction) plumbing from the pump. Put a tray under the pump inlet. Connect and turn on the city water hose. Check the pump inlet for water leaking out. If there is no water leaking out, the pump is ok.

[Rudy]

On the Nautilus panel, be sure to have the control knobs turned completely. If not, the water pump will cycle on dry camping.

[Rabbit]

Might be air trapped in a line. Recently had a similar problem with pump cycling. Yet when on city water everything seemed fine. Turned out the line to the outside shower connection had air trapped in it. Evacuated the air and all was fine.

[BGauweiler]

We are having a similar issue with our 2022 2500RL. We almost never have water hookups available and rely on our fresh tank and pump while camping. Our pump cycles every 20-30 minutes all day and at night, which is very irritating. I’m wondering if you solved your issue and how to did it.

[Country Campers]

BGauweiler

When the onboard pump cycles when there is nothing calling for water that usually means that there is a leak somewhere in the system, finding it is the hard part. You would have to look at all of the connections, under the sinks, shower , toilet, behind the water panel in the pass thru storage, outside shower port if you have that, and so on. Cycling every 20-30 minutes could also mean that the water in the lines is cooling, or even the whole RV is cooling allowng the pressure to drop and the pump thinks it needs to come on. One thing that you can start doing is leave the pump off when not needed. I know it is a pain to turn in on each time it is needed but if you would have a major leak and are not at the RV to hear or see it then the pump will run continuously until the fresh tank is empty. Even if we are sitting outside the pump is off.

How much does the pump run when it cycles, is it just a burp or does it run for a minute or so?

Brian

[Cate&Rob]

BGauweiler

If you read back though all the posts of this thread, possible locations of leaks or how the pump check valve may be the cause are all discussed in detail. The cause of your pump cycling will be one of these.

Rob