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Topic: Water pump cycling when not in use. Pump is on. (Read 289 times) previous topic - next topic
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Water pump cycling when not in use. Pump is on.
I'm on shore power, not connected to city water, have my water pump turned on, and very couple of minutes I hear the pump working for about a second even though no outlet is in use. Is this normal? There is no leakage under the kitchen and bathroom sinks.
2001 26.5 Mid-Bath
Re: Water pump pumping "on its own"
Reply #1 –
No. That isn't normal.

You have a leak somewhere.  Either in the plumbing (water escaping the pipes) or inside the pump itself (no water escaping, but leaking from the high pressure side to the low pressure side).

A second every few minutes indicates a very small slow leak.

I would check everywhere in, around, and under the coach for signs of a leak.  If you can't find any moisture, I would suspect the pump, especially if original on a 2001.

Rich
'03 MB in NC
2003 MB
Re: Water pump pumping "on its own"
Reply #2 –
ah the water pump .......

Do a water pump search in the search box.   Sadly or wisely you'll find many many posts on this favorite topic of mine.
personal fine art photo stuff
TF Mack | Flickr
It's all good .......
2014 Twin King
Re: Water pump pumping "on its own"
Reply #3 –
As far as I remember the previous owner told me that the pump got replaced - already from the first owner, meaning this must have happened more than 13 years ago. I removed the board that covers the space behind the converter (luckily only held in place by velcro). Also there everything is dry. See also attached photo Same behind the shower faucet (which I replaced just recently). I now closed the valve in the pipe coming from the water tank - and the pumping stops. Sounds not like very good news.

I'm driving now from Camp Comfort in Ojai, CA to Jojoba Hills in Aguanga, CA. I will check there whether I see any leaks under the rig.
2001 26.5 Mid-Bath
Re: Water pump pumping "on its own"
Reply #4 –
If the water heater is leaking from the drain plug or from the pressure relief valve that can trigger the water pump.  If the drain plug is dry but the PRV is wet then recreate the dome in the water tank. Hope this helps.
Re: Water pump pumping "on its own"
Reply #5 –
Good point, Ed.

About the pump: the Whisper King pumps have been pretty reliable, but if it's thirteen years old, then Rich's suggestion of a problem inside the pump is also worth considering. If you can't find any evidence of a leak, then it might be worth replacing the pump. New ones are not that expensive. Even if it turns out that wasn't the problem, you'll have a spare pump--not a bad thing to carry. I think Shurflo's "Revolution 4008" is the currently recommended model.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
 
Re: Water pump pumping "on its own"
Reply #6 –
You may have no problem. As water cools, the pressure drops. For instance, if the water heater has been on, but is now turned off, as the water slowly cools, you would expect the pump to occasionally cycle. Conversely, it is wise to have the pump off and a sink faucet open while the water is heating to keep the pressure from building beyond the operation range of the plumbing.

Steve
2004 FL
2013 Honda Fit
Re: Water pump pumping "on its own"
Reply #7 –
Quote from: Ed & Margee  - 
If the water heater is leaking from the drain plug or from the pressure relief valve that can trigger the water pump.  If the drain plug is dry but the PRV is wet then recreate the dome in the water tank. Hope this helps.
What are PVR and "dome in the water tank?"

On the road in a minute. Back here in probably four hours.
2001 26.5 Mid-Bath
Re: Water pump pumping "on its own"
Reply #8 –
"What are PVR and "dome in the water tank?"

Pressure Relief Valve = PRV

The 'dome' is more properly referred to as a bubble! On some units the hot water tank needs to have a bubble of air to allow for expansion when heated. To establish the bubble start by turning the water pump off. Then open several or all faucets. Now go out and open the pressure relief valve ** Careful here, if the water is hot you may get burned **

When the valve is open you are going to experience an outflow of water. Let it happen and when it is finished snap the PRV back in place. You should now normal everything up and turn the water pump back on. It should not run on it's own.   ;)
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!
Re: Water pump pumping "on its own"
Reply #9 –
Quote from: Steve  - 
You may have no problem. As water cools, the pressure drops. For instance, if the water heater has been on, but is now turned off, as the water slowly cools, you would expect the pump to occasionally cycle. Conversely, it is wise to have the pump off and a sink faucet open while the water is heating to keep the pressure from building beyond the operation range of the plumbing.

Steve


In this case, my pump cycles once or twice over 4-5 hours, not once every few minutes.

Rich
'03 MB in NC
2003 MB
Re: Water pump pumping "on its own"
Reply #10 –
Hi Nick; I've had the rubber material in my sink faucets (washers) shrink up after turning the faucets off, causing just a very small drip. That results in cycling of the pump. Retightening the valve(s) fixes that. Maybe someday I'll replace the seal(s). [don't hold my breath!].
    A picture of the Pressure Relief Valve, either temperature or pressure related:  Camco RV Water Heater Temperature and Pressure Relief Valve - 3/4" Valve w/...                      RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Water pump pumping "on its own"
Reply #11 –
I should have included a picture that I already had. I put a piece of 3/4" nipple on the replacement valve (old one was ruined when I turned heater on without a full tank of water, my bad!). When I release the valve it dumps water more out on to the ground, than in the water heater.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Water pump pumping "on its own"
Reply #12 –
This topic was something I had searched for prior to our trip to Yosemite a week ago. I looked high and low on how to establish the “bubble” in the HW tank after flushing the tank to release the built up mineral deposits.

I hadn’t done  this maintenance ever. My bad. As I flushed the tank several times using a Camco flushing tool, I noticed small flecks of mineral deposits flow from the tank. I thought to myself that there really wasn’t too much build up until the next day when I saw the residue in my driveway.

Oh my, I was shocked to see how much crud was in the tank. 😖 For such a simple procedure, there really is no excuse not to flush the HW tank.

This conversation is definitely going in my “bookmarks”. Thanks. And as Andy wisely suggested, I do have a new water pump waiting in the rig for that special day when I’ll need to get down on my knees and face the music.

Let it flow.

Kent
2015 27' RB "MissB.Haven"
Re: Water pump pumping "on its own"
Reply #13 –
"I put a piece of 3/4" nipple on the replacement valve..."

RonB

Now that's a neat trick... guess it falls into the category of "Why didn't I think of that so many years ago?"   ::)
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!
Re: Water pump pumping "on its own"
Reply #14 –
Quote from: Kent Heckethorn  - 
This topic was something I had searched for prior to our trip to Yosemite a week ago. I looked high and low on how to establish the “bubble” in the HW tank after flushing the tank to release the built up mineral deposits.

I hadn’t done  this maintenance ever. My bad. As I flushed the tank several times using a Camco flushing tool, I noticed small flecks of mineral deposits flow from the tank. I thought to myself that there really wasn’t too much build up until the next day when I saw the residue in my driveway.

Oh my, I was shocked to see how much crud was in the tank. 😖 For such a simple procedure, there really is no excuse not to flush the HW tank.

This conversation is definitely going in my “bookmarks”. Thanks. And as Andy wisely suggested, I do have a new water pump waiting in the rig for that special day when I’ll need to get down on my knees and face the music.

Let it flow.

Kent
Good thing about living in an area where you have to winterize I guess. You have to flush your hot water tank annually
Discuss anything with anyone and disagree agreeably. Always be polite and respectful.
Re: Water pump pumping "on its own"
Reply #15 –
It seems to me that Rich nailed it in your first reply.  Check everything for leaks.  If you find none, you have a bad pump.  From the sound of it, it is a check valve internal to the pump.  While those can be replaced, with an older pump, it makes more sense to replace the pump.

The comments on servicing and maintaining the water heater are good recommendations in general, but I don't think they causally relate to your pump cycling every few minutes.  So, service the water heater, check everything for leaks (do you know about using white paper towels to do that?), and if you find no leaks, replace the pump.

Ken F in NM
'08 MB