# Very variable water pressure



## DocHoliday (Jul 18, 2008)

Pressure at taps and loo flush varies from quite low to high, but it doesn't seem to be dependent on battery condition. I've noticed the problem for a few weeks. I recently replaced the pump (Reich tandem 19L/min, 1.4 bar) because it was starting to burn out, and whilst that has upped the minimum water pressure I get, there is still major variability. Often the pressure is so low the flush water will not circulate all the way around the loo. One odd symptom is that when the Truma has been on and there is hot water, the loo flush is strong.


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## prof20 (Jan 11, 2007)

Hi DocHoliday,
I get the same problem from time to time on my 1997 B544. I've also replaced the Reich pump.

Mine is an import and had been used down South for a while before I bought it, and soon after purchaseI lost both hot and cold water.

I traced it down to the hot water feed pipe from the Truma heater which is at the bottom of the compartment below the heater. It was completely blocked with limescale, and removing it from the pipe solved the problem of the water supply. 

Be prepared for a minor flood if this is your problem, and have something to catch the water remaining in the boiler when you disconnect. 

It didn't solve the problem of the low pressure to the toilet flush. 

I assume there is a limescale blockage somewhere within that system, it is something I have put up with, I flush the loo with the shower head.

You access the pipe by removing all of the lower panels in the compartment.

It is secured to the right of the bottom of the dump valve, in the case of my van with a jubilee clip as opposed to the crimped clamps used by Hymer, which leads me to think that it is a recurring problem.

I have had the van for four years, and the problem has repeated itself about four times.

From time to time small pieces of limescale come out of both taps.

I assume that there are fluids or additives on the market to dissolve all of the limescale left in the Truma, but it is one of those jobs I haven't got around to yet. 

Hope this helps.

Regards,
Roger


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## DocHoliday (Jul 18, 2008)

I've investigated along the lines that Roger suggested, but I can't detect any limescale in the hot feed pipe coming off the boiler. I've never had limescale coming out of the taps, either.

The symptoms are becoming more pronounced. As I said, the loo flush is weak, except when there is hot water in the boiler - then it is very strong, at least initially. The pressure out of the hot tap is also strong initially. In fact, for the first few seconds, even if the bathroom mixer tap is set to cold, hot water comes out. Then it goes cold. Then if I turn the tap to a 50/50 mixture of hot and cold, the water runs cold, then there's an air lock for a few seconds when nothing at all comes out, then normal service is resumed.


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## peejay (May 10, 2005)

Doc;
I'm certainly no expert but did you get the wires the right way round when fitting the new pump? It might be completely wrong but for some reason this has stuck in my mind.

See this thread......

http://www.motorhomefacts.com/ftopicp-90828.html#90828

Pete


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## DocHoliday (Jul 18, 2008)

That did it, Pete! At least as far as the loo flush is concerned. I swapped the wires at the pump and it made a big difference to the flow rate. For the record, they are now connected blue to green and brown to pink.


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## peejay (May 10, 2005)

Blimey - it's not often I can help on a techie type question. Glad to have been of assistance.

8) :lol: 

Pete


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## apxc15 (Dec 1, 2007)

Thanks for bringing that little gem to my attention peedee. 

I've suffered with poor pressure since I got the van and bought a new pump a couple of weeks ago, with no marked difference in pressure.

I've just reversed the wires as recommended (Blue to Brown and vice versa )and problem solved.

Shame I didn't see this before I changed the pump, it would have saved me £30.

Pete 8)


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## peejay (May 10, 2005)

apxc15 said:


> Thanks for bringing that little gem to my attention peedee.


No probs Pete, it was Tonto who supplied the info, although sadly he doesn't appear to be around anymore, I just did a search for the info.

BTW, my nickname is peeJAY, not peeDEE, we often get mixed up, i'm the handsome one if it helps avoid future confusion. :roll: :lol:

Pete


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## apxc15 (Dec 1, 2007)

peejay said:


> apxc15 said:
> 
> 
> > Thanks for bringing that little gem to my attention peedee.
> ...


Sorry, I really must learn to read :roll:

Pete 8)


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