# losing water pressure 1993 S700



## funkyronster (May 1, 2005)

I know this is a common fault, but because I am in the Sahara desert I can't stay online long enough to search and search, so maybe somebody would be kind enough to repeat the answer.

My S700 Old style Hymer has a big water tank under the settee, with a Reich pump hanging into it, above the Reich pump is what I assume to be a small plastic non return valve.

For a while now the taps don't deliver water immediately, the time taken being proportional to the amount of time no water has been drawn.

Normally I would just assume its the NRV, but before I undertake the long task of getting a new NRV to Morocco, I would just like to check my facts with somebody.

The problem has been getting gradually worse over the last year, but I have also noticed that the toilet flush, never particularly strong, has all but disappeared.

But the weird thing is that in the last few weeks it has been dripping into the pan, causing a puddle of fresh water in the bottom of the pan.

Now I can't understand why this is so, and I am wondering if there is more than one NRV in the system, or whether this is a separate fault. I can't understand why water should be dripping into the toilet, when the system is losing pressure anyway!

Any ideas?

Cheers

Ron


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## johnthompson (Jul 29, 2010)

I think you will find it is another pump in tandem. It was on my 1992 S700.

One pump went down but the other kept on working but at a reduced presure.

I replaced both pumps with a new high output version and the presure is back up again.

Have you also checked that the filters in the taps are not choking up. Mine were and I think it was the back presure from this that burnt out the last pump I had fitted. 

Now on my third pump and everything seems OK now.

John


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## hymerjeff (Sep 3, 2009)

*losing water pressure*

Hi funkyronster.

Had similar problems myself last year.
Tried reversing the two wires, made no difference.
Bought a new pump, problem solved. Dont forget that
there are two 19ltr 1.4 bar Reich pumps one with a
built-in NRV and one without. Found out later that only
one of the impellers was working.(sealed unit).
Water dripping through the toilet. I was advised
to change the solenoid valve to the toilet, so I did,
only for the same thing to happen some three months
later. Decided to disconnect the inlet pipe before the
solenoid, (cap off live side) put a piece of hose over the
outlet into the pan, operated flush switch (to open the valve) and blew down the pipe blowing out several small grains of
sand. Never had a problem since!
Hope this is of use to you.

JEFF.


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## funkyronster (May 1, 2005)

Thanks both!

If I have a second pump I don't know where it is!! There is a single pump in the tank, and it is def working ok, as I get normal pressure, albeit after a lengthy wait. My pump has a seperate NRV mounted inline just above the pump - as soon as I buy some new jubilee clips I will dismount it and try and clean it - the present clips are corroded through (maybe the corrosion has been swept inside the pump/NRV.

The single pump I have in the tank switches on whenever I use both taps or the flush.

Toilet - could you give me an indication of where the solenoid valve is and what it looks like?

Thanks

Ron


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## funkyronster (May 1, 2005)

*More information*

I have now discovered that the toilet is not functioning at all. When I press the switch, some contact is made because the ammeter drops about an amp, but the main pump does not operate. I think maybe the toilet leak is the water in the pipes that is above the level of the pan - ie the water to the bathroom sink and shower, by gravity.

I still haven't found this solenoid op valve - the wires and the water feed pipe disappear into the bowels of the van!

Also - I get a lot of gurgling and sputtering when I try to draw hot water - it eventually does come, but after a much longer time than the cold.

Ron


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## grizzlyj (Oct 14, 2008)

Hi

From how you describe whats happening this may be entirely wrong, but have you got an accumulator?

When the weather is cold or low pressure sweeps in it takes a lot longer when turning the tap on in our non-Hymer camper to fire the pump up. 

I should put some more air in the accumulator, but if its been warm, or the heaters been on warming the under floor cavity it isn't an issue.

Desert nights are cold from what I've heard 

Jason


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## funkyronster (May 1, 2005)

*no idea*

No idea what an accumulator looks like! All I have seen is a junction manifold adjacent to the boiler, which is a short plastic pipe with lots of connections coming off it.


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## clive1821 (Mar 27, 2010)

Another idea is, you have a leak some where which will cause the same issue, loosing pressure until the pump regains the pressure, I found one of the connecting pipes in the tank from the sump pump was leaking only a little but was enough to cause the issue you have, if you have this sort of issue it could be anywhere in the cold or hot water systems, if you have a Truma heater check the cold water feed at the bottom and the hot water feed out at the top side of the heater and the pressure relief valve at that point... of cause the drain valves check them as well...


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## grizzlyj (Oct 14, 2008)

*Re: no idea*



funkyronster said:


> No idea what an accumulator looks like! quote]
> 
> Mine looks like its about a litre in volume, is immediately after the pump, flow in and out at the bottom and a push bike valve on the top. They can be a lot bigger, perhaps 10l, but if you can see all your plumbing bits it would be obvious I would think?. You're supposed to use a bike pump to set the pressure in it via the valve to suit your particular pumps output, minimising its cycling, and therefore wear and tear.
> 
> Jason


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## BlackScorpion (Apr 30, 2008)

*Water probs.*

I have the same problem as the originator of query, have had it for some months, have changed the pump and checked the NRV but still problem persists. Can someone tell me if it is a direct connection between pump and taps, or is there a connection somewhere ? It getting a bit annoying when I have to turn on the tap to get a head of water, just to flush the toilet !!


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## BlackScorpion (Apr 30, 2008)

*Pump problems*

I've solved the problem, the reason was the NRV was not closing properly ,even after blowing thro' a number of times, SO, I decided to fit another one way valve in the water line just above the pump. I got one from the usual source (E-Bay)

Try http://cgi.ebay.co.uk/8mm-Fuel-one-...=330515956968&ps=63&clkid=6623710000458655467

They supply anywhere.


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## funkyronster (May 1, 2005)

*still no joy....*

I replaced all the NRV's I can find......improved a bit, but still takes ages in morning for water to come through.

Toilet still the same - does anybody know if it has it's own NRV?

I don't have an accumulator - vans too old! I recon the guy who said there must be a slow leak somewhere is on the right track.

Or maybe the whole problem is the toilet flush mechanism - its old and had a lot of use!!!!


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## johnthompson (Jul 29, 2010)

Check all joints we found some in the bottom of the wardrobe on our S700 that had the original plastic clips on and they had all broken. I only noticed when water appeared under the wardrobe. We have replaced all clips with Jubilee clips and put a new pump in and everything is fine now. 

We had a leak in the Truma boiler that we could not detect even on a hosepipe. Each time we put it back into the van it leaked on test it didn't. We eventually replaced the boiler with a new one with electric element built in.


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