Lack of Water pressure once pump turned off

[DocMike]

I have only one winter under my belt so these questions go out to those more senior RV'ers out there. This past weekend we were camping in the NC mountains and the temp dropped to 28 degrees and it froze the water line (hose) into the RV from the campground source. No frozen pipes or damage inside but I was wondering what others did to prevent the outside hose from freezing.

Second question deals with what could be wrong with the fresh water tank as it will not hold pressure once the water pump is turned off. When the water pump is turned on it only runs for a few seconds then cuts off. As soon as you turn on the sink faucet the water runs for a second or so then the pump cuts back on. If you turn off the pump the water pressure drops to nothing in just a couple of seconds.

I tried to Search threads and Posts on this forum but could not find anything. Please advise.

Doc

[JamieGeek]

For the frozen hose you can either:

• Disconnect one end of the hose and drain it the night before, or
• If you have sewer and leave the grey tank valve open let a faucet drip

In the past when our pipe would freeze we would just wait for it to thaw in the morning sun (and use the pump if we really needed water).

As far as your pump not holding pressure: I bet you have some debris stuck in the valves. Not sure how you'd clean them, though other than disconnecting the pump and looking (perhaps check the strainer for debris if there is some in there then you may have some in the pump).

[DocMike]

Jamie,

Thanks, will remember "the drip" next time. Also, I'll look into debris in the pump...once it warms up a little.

Long ago, in a life far far away Sheree and I purchased a Mobile Home during my college days...managed to move it to Chapel Hill when I went to Dental School. BUT, back then they had electrical "heat-tape" that you would wrap around the waterline into the Mobile Home to prevent freezing and it would automatically cut on at a certain temp. I'm wondering if they still make that stuff or even a water (hose) line with the heat-tape already wrapped?

Doc

[fhenn]

They brought put a heated hose a couple of years ago, it blue in color.

[JamieGeek]

Originally Posted by DocMike

I'm wondering if they still make that stuff or even a water (hose) line with the heat-tape already wrapped?

Forgot about that stuff. Yeah you can still get it at home depot. They also sell it for gutters to keep them from freezing.
Here you go: Frost King 18 ft. Automatic Electric Heat Cable Kit-HC18A - The Home Depot
(Hmm they say that tape isn't for use outdoor. It looks pretty sealed to me though.)

Ah here is an outdoor one from Lowes:
https://www.lowes.com/pd/EasyHeat-30...-Cable/3115571

[DocMike]

Fhenn,

Thanks, next trip to CW I'll pick up the heated hose.

Doc

[Chance]

Camping World is advertising in MotorHome Magazine the Freeze Ban 2000 Heated drinking water hose. Starts at $89.97 and comes in 12, 25, and 50 foot lengths.

I haven't used it so can't recommend for or against. Just thought you'd be interested.

[EA37TS]

Doc,

We camp in cold weather often and when temps are scheduled to drop below freezing I make sure I have water in the fresh water tank and then completely disconnect my water hose and store it in a heated compartment.

If you are going to be in cold weather enough you could get one of these.

https://www.amazon.com/Camco-22911-H...ing+water+hose

I have, however, found that most times the campground will turn off the water supply and disconnect your hose to prevent their hydrants from freezing so an electric hose or heat tape would serve no purpose what so ever.

[Chance]

Originally Posted by DocMike

....cut....

Second question deals with what could be wrong with the fresh water tank as it will not hold pressure once the water pump is turned off. When the water pump is turned on it only runs for a few seconds then cuts off. As soon as you turn on the sink faucet the water runs for a second or so then the pump cuts back on. If you turn off the pump the water pressure drops to nothing in just a couple of seconds.

I tried to Search threads and Posts on this forum but could not find anything. Please advise.

Doc

Doc, I may not be understanding the question correctly, but are you thinking that the water tank is pressurized? If so, that's not the case.

The water tank in most motorhomes remains at atmospheric pressure, and the pump takes suction from the tank and pumps pressure into the motorhomes pipe system. Some RVs have a small pressure accumulator that stores a little water volume under pressure which keeps the pump from cycling constantly. As soon as we open a faucet it's normal for the pressure in system to drop instantly (or very quickly if you have an accumulator) which causes the pump to come on again.

Sorry if I misunderstood your question.

[GMac]

Originally Posted by DocMike

Second question deals with what could be wrong with the fresh water tank as it will not hold pressure once the water pump is turned off. When the water pump is turned on it only runs for a few seconds then cuts off. As soon as you turn on the sink faucet the water runs for a second or so then the pump cuts back on. If you turn off the pump the water pressure drops to nothing in just a couple of seconds.

Doc

Not sure anyone answered your second question. Am I reading it wrong? It sounds like your pump is working as it should.

When turning on, the pump pushes water into the line and then shuts off ( a few seconds).
When sink turned on, now the demand for water, pump cycles on and off for water flow.
Turn off pump, there is now nothing to push/feed water as demanded, thus zero water pressure.

I hope I didn't misread your initial question.

[DocMike]

GMac and Chance,

Yes it is doing what you have said. But I was thinking that up till now there was a little water reserve under pressure. Could just be faulty memory on my part.

Doc

[samven]

I just had the exact same problem as you. What I found was there was some ice in the water line. When the pump was running it seems that the pulsating would push a bit of water through but the min the pump went off so did the water. All my lines are inside but the one going to the bathroom sink and toilet run through a void behind some drawers and they boxed that in so the warmer inside air could not get to the line there and they got slushy. I used a hair dryer and blew air from under the sink back and in about 5 min the system started working again.

[JamieGeek]

Interesting: My interpretation was that it wasn't holding pressure (e.g. with all sinks off run pump until it stops, turn the pump off and wait a few minutes--there still should be pressure in the lines until you open a faucet).

If you want some "extra" (so someone can flush the toilet in the middle of the night without the pump running) you can install an accumulator tank:
Shurflo 2-Gallon Stainless Steel Tank - Shurflo 3400-002 - Fresh Water Tanks - Camping World
That will hold a bit more pressure and allow a more water to flow before the pump starts to run.

Wow those heated hoses are a lot more expensive($80-$100) than simply picking up some heat tape (~$35).

[Chance]

Originally Posted by DocMike

GMac and Chance,

Yes it is doing what you have said. But I was thinking that up till now there was a little water reserve under pressure. Could just be faulty memory on my part.

Doc

Doc, you may be right. If so, you may have a slight leak through check valve back to tank. I'd expect that if you leave the pump on with no water being used, that it shouldn't cycle very often at all. If it does, you likely have a small leak to outside or a leak back into tank via back flow.

I went through a minor slow leak on my motorhome which made pump run occasionally when left on. My wife would forget to turn it off at night after flushing toilet. Because pressure would bleed faster than normal, I looked for the leak.

[EA37TS]

Originally Posted by JamieGeek

...

Wow those heated hoses are a lot more expensive($80-$100) than simply picking up some heat tape (~$35).

That's why I disconnect my hose and put it in the wet bay overnight in cold weather. The wet bay is heated by the furnace so it won't freeze overnight.

Doc,

After I turn off my water pump there is generally enough residual pressure for one quick (3 or 4 second) flush of the toilet and that is it. If I do not crack a faucet or flush the toilet that residual pressure will remain in the lines for quite some time indicating there are no water leaks in my system.

[Joe-FL]

Originally Posted by DocMike

I have only one winter under my belt so these questions go out to those more senior RV'ers out there. This past weekend we were camping in the NC mountains and the temp dropped to 28 degrees and it froze the water line (hose) into the RV from the campground source. No frozen pipes or damage inside but I was wondering what others did to prevent the outside hose from freezing.

Second question deals with what could be wrong with the fresh water tank as it will not hold pressure once the water pump is turned off. When the water pump is turned on it only runs for a few seconds then cuts off. As soon as you turn on the sink faucet the water runs for a second or so then the pump cuts back on. If you turn off the pump the water pressure drops to nothing in just a couple of seconds.

I tried to Search threads and Posts on this forum but could not find anything. Please advise.

Doc

We used to stay in the north until the first part of December before heading to warmer travel. The heated water hose is the only way to go. In addition, when hooked to city water when temps are below 25 to 30 degrees I would leave a faucet slightly dripping overnight. Of course make sure your gray tanks are open.

Unless I also misread something, your fresh water pump is working exactly as it is suppose to work.

[DocMike]

Thanks to all for input


Like I said, it might be bad memory cells on my part. I have some cleaning to do this weekend and I test it with the pump on and see how long before it cuts back on.

I'll be looking for the heat tape and use when needed...along with a slow drip.


Doc

[bevedfelker]

Doc -- I pretty much only have pressure when the pump is running. If I close the faucet and the pump stops, I only get a little water at slow trickle until the pump starts again and pushes the water. I agree with Jamie -- to have pressure without operating the pump you will have to install an accumulator. Water flow into a bladder in the accumulator and there is a pressure charge that pushes the water from the accumulator. Without it, you are going to get the loud pump noise from under the bed when someone flushes while camping off the grid.

Dave's suggestion for having water in the fresh water tank when the park water freezes is a good idea. The fresh water tank won't freeze because of its location inside under the passenger twin bed. You can use that in the AM to push water to the hot water heater. If you disconnect the water hose at night and drain it completely, you have a good chance of being able to reconnect it in the AM providing the park water stub line does not freeze.

[Mr Sunshine]

Originally Posted by JamieGeek

If you want some "extra" (so someone can flush the toilet in the middle of the night without the pump running) you can install an accumulator tank:
Shurflo 2-Gallon Stainless Steel Tank - Shurflo 3400-002 - Fresh Water Tanks - Camping World
That will hold a bit more pressure and allow a more water to flow before the pump starts to run.

I installed an accumulator a few months ago. Just not for the reason stated here. I put it in to take out the pulsing from the pump. I didn't have any hose or clamps, but I was able to install it by removing 3 of the 4 pump mounting screws and twisting the pump a bit. It does the job like a champ, and now the pump is whisper quiet.

Never tested to see how much water you could run after the pump is shut off, it would have been barely enough for one flush. The accumulator I put in is .7 liter.

[SuperD]

I lived in my Tuscany full time for four years, another coach for three years. I used a 25' hose, wrapped it with heat tape in a long spiral, and covered it with foam pipe insulation taped about every six inches. If I was going somewhere in the coach I rolled up the hose and stored it like any hose. I never had a freezing problem in seven years, and a whole lot cheaper than a heated hose!

It sounds like you have bad check valves, they can be removed and cleaned, might just have debris which is not allowing them to work. I would remove and dissassemble the pump and clean it, depending on where it's mounted it doesn't take long, there isn't much to the assembly. An accumulator tank helps to even out water pulses at low flow rates but that doesn't seem to be your problem.