Water pressure switch

Hi, just taken delivery of our Autosleeper Stanway and so far we are very pleased with the layout and equipment. 
 
I have noticed that the water pressure switch is making a chattering noise when the sink taps are turned on and have tried adjusting it as per the manual but can't find a position where it quietens down. 
It sometimes carries on for a few moments after the tap is turns off. 

Anyone had a similar experience or can help?

Hi Cookie

Beware of fiddling too much with the pressure switch. They are curious beasts and can be very tricky to tune at times, often depending on whether you are on hook-up or not, and the state of your leisure battery. Pumps can be very voltage-sensitive.

It sounds as if you have nothing to worry about though. The pump running on for a few moments after the tap is turned off is perfectly normal. The pressure has to build up in the system before it can trigger the pressure switch to turn it off.

Chattering is quite common when water is being drawn off slowly, but it shouldn't be happenning if the tap is fully open. That does sound as if the pressure switch is not perfectly adjusted. Are you sure "chattering" is a good description, or is it just the rather noisy pulsating of a bulkhead mounted diaphragm pump? (I don't know which pump you have fitted.)

I'd be inclined to leave it alone as long as it works, and get your dealer to have a look next time you are there. No damage is likely to be done, as these systems either work or they don't.

Hope this helps.

Dave

Hi Dave,
Thanks for the reply. It is definitely a chattering noise, the pressure switch is in one of the seat lockers and I can feel it. It is like the switch is clicking on and off very quickly. It does go off after a while when the taps are turned off though.
The pump is a Whale immersed in the tank I believe on this model.

Dealer visit I think Cookie - though not urgently.

I got ours to look at my pressure switch as I was there about something else last Friday. He tinkered for several minutes and got it working very smoothly (he's quite an expert as we have found in the past) but said it would probably need a tweak before long as they can be very temperamental. Even switching on the lights when off hook-up can cause the pump to run on, or not come on at all.

His advice was to mark where it was when he left it, then to turn it no more than an eighth of a turn at a time, and keep a note of how far I moved it from his marked position. A tiny movement can have a dramatic effect.
 
One of his pet hates is owners who fiddle about and give the knob multiple turns and have no idea how far, or which way they have turned it - leaving him to sort it out. If they have found the other pressure switch which controls the inlet pump he really has problems, because the two switches influence each other on the wonderful Whale system, and balancing them can be a real headache.

Onwars and upward, eh!

Dave

The difficulty that I have is that there is no lock nut on the adjuster which is so loose that it gets easily nudged.

Whoa there hoss!!

There was probably nothing at all wrong with the pressure switch before you started messing with it!  Sorry!

Why?

As a general rule:

1.  There is NO accumulator on the cold water supply.  So cracking open any cold water tap will drop the pressure immediately and the pump will cut in.  If the tap isn't wide open by the time the pump cuts in then (because liquids are incompressible) the pressure will build IMMEDIATELY, the pressure switch will operate and the pump will stop.  Because the tap is still open the pressure will immediately drop and the pump will re-start; causing the "chattering" of which you are complaining.  It is normal.

2.  There IS an accumulator on the hot water supply.  So cracking open any hot water tap will drop the hot water pressure very slowly as the air in the accumulator expands. When the pressure drops low enough the pressure switch will operate and the pump will start.  Unlike the cold water system, even if the tap isn't wide open, it will still take time for the pressure to build up and the pressure switch to operate and stop the pump.

I suggest that you just put the pressure switch back to where it was before you started "adjusting" it and before you damage the pump by over pressuring the internal diaphragm and causing damage.

Hope this helps. 

Best regards,

Dutto wrote:I suggest that you just put the pressure switch back to where it was before you started "adjusting" it and before you damage the pump by over pressuring the internal diaphragm and causing damage.

Excellent description of the processes involved Ian, but is there a diaphragm in a Whale submersible pump?

I can appreciate Cookie's frustration. The wonderful new system can be a pain in the backside, and this has nothing to do with earlier comments about not liking the faff and fiddle!! As I reported above, our dealer has warned me that however carefully the pressure switch is adjusted on one day, it may need a further tweak on another day when conditions in the van are different.

Before he adjusted ours it worked perfectly on hook-up. On battery power it was fine during the day (solar panel providing top-up power I presume) but when the lights were switched on at night the water pump would run on continuously. Turning on the cold tap in the bathroom, then abruptly turning it off would sometimes jolt the pressure switch enough to activate it - but not always.

Fortunately I did as I was told (for once) and resisted the temptation to fiddle, and marked the position of the factory setting in case the knob was nudged.

Don't you just love progress!!

Dave

Hi,
So yet another example of a new system which doesn't work as well as the old, my symbol which has a whale pump with the built in pressure switch works fine, my control panel with switches for main, pump lights and battery/water level does not need to be reset every now and again, my battery master keeps the van battery topped up, why do they think the modifications and upgrades are an improvement?
Chris

Hi there,

Ah'm no daft!!    Hence the phrase "As a general rule ..." 

The submersible pumps, as a general rule,   have an impeller rather than a diaphragm.

I had one on a Silhouette caravan that worked perfectly for over ten years without adjustment BUT it was on permanent EHU and had no fluctuation of voltage and hence outlet pressure.

Personally, in the case described and as it has already been messed with, I would set the pressure switch just below "as high as possible" and then leave it alone as much as possible.  

Hope this helps. 

Best regards,

Dutto wrote:The submersible pumps, as a general rule,   have an impeller rather than a diaphragm.

I had one on a Silhouette caravan that worked perfectly for over ten years without adjustment BUT it was on permanent EHU and had no fluctuation of voltage and hence outlet pressure.

Thought so, but thanks for the confirmation.

Your Silhouette experience is reassuring. I can live with the occasional tweak, and have made an access hole in the top of my nifty cover for all the water pipes and vulnerable gubbins in the underbed locker.

What really concerns me (though not enough to lose much sleep ) is when the pump goes wrong - on the first day of a three week holiday in France. (Sod's Law is certain to apply!) Having to drop the tank to replace it is not a good example of forethought on the part of Messrs AutoSleepers.

On reflection, it seems likely that one of their financial cutbacks was the sacking of their "Head of Joined Up Thinking". His input is sorely missed, and may well cost them in the long run!!

Dave

P.S. If they had any sense at all they would create a new post - "Head of Agricultural Engineering". It worked, and when it went wrong you usually needed nothing more than a big hammer.

Gromit wrote:
I ..... made an access hole in the top of my nifty cover for all the water pipes and vulnerable gubbins in the underbed locker.

You've read my thought, Dave: I've been concerned at the vulnerability of the pipework etc underneath the O/S under-set/bed, and have only used it for lightweight stuff which I gingerly place on top of the gubbins. I hadn't thought of making a cover - but it's an excellent idea. So if you wouldn't mind telling me how you made your nifty cover, I'd be most grateful. Whether my basic DIY skills are up to copying it will remain to be seen!

Thanks,
Cymro

No problem Cymro. The nifty cover doubles as extra storage for a few small items, so twice as useful.

When are you coming up to Autosleepers? You did say but I forget.

Dave

Ah! Was there last week, having Air-Tops fitted, etc. Village café is good for breakfast and killing time!
I fear I overlook Ed letting you know. Sorry.
c
Cymro

That's a shame. You could have called in for a cuppa and studied the nifty cover. Would have been nice to meet you and Mrs Cymraes.

Now I shall have to take photo's. Is there no end to the toil and strife on ASOF!!!

Dave

My shout when we do meet! Next time we stay at Tewkesbury, perhaps.

Well, the only time that I have had problems with over-running or with pulsating water is when I have accidentally nudged the knurled adjuster which is all too easy to do.  I do not find it at sufficiently sensitive to voltage variations to have to readjust. And if it is wrong (however far you may have wrongly adjusted it) the instructions in your manual will tell you exactly how to get it right again - if you follow them!  Just very occasionally and particularly in evenings when the water in the pipes has contracted slightly with temperature I hear the pump run for less than half a second as it puts the pressure back up.
And on my vehicle it is definitely an impeller pump - you can tell from the noise it makes when pumping which is different from a diaphragm.

Many thanks for all your input! I have followed the instructions in the manual for adjustment and it is now working as it should. I will monitor its performance while away and see if it varies under different situations.