Whale pump occasionally cycling

[Mark31415]

We have the usual whale external pump set-up.

Turn on the tap, pump runs, water flows.
Turn off tap, pump runs on for a few seconds then stops,
So far so good….

However after a while the pump will run on again for a few seconds when nothing has been opened. Very annoying in the middle of the night.

I've not got any dripping taps.
The drain tap does not look to be dripping
There are no signs of any leaks on the internal pipe-work

There was a bit of a leak where the body plugs into the van but I replaced the o-ring and that stopped. I've also added a bit of silicon lube to teh o-ring so that's a super snug fit with no snagging.

I've tried pressing the button on the inner part of the sensor thing which didn't seem to do anything.
For now all I do is turn the pump switch off at night and when we go out which is probably best practice anyway.

Is this normal behaviour for one of these pumps caused by changed in water pressure through a drop in temperature etc or somethign I can fix. Not a big problem but about to go away for a few days so a chance to have a play.

 

[audiorob]

https://www.whalepumps.com/rv/siteFiles/resources/docs/resource-library/WhaleAdjustingyourpressureswitchb.pdf
worth using this link to get the pump optimised - helpfully provided by Whale.
The pump is affected by voltage so you may need to re-adjust between using on mains or on battery.
Also the pressure in the system is affected by temperature, so if the temperature drops at night the pressure lowers and the pump runs momentarily.
I always switch off the pump (and water heater) at night especially as in my van the thing is immediately below our heads!

 

[Woodentop]

We have the usual whale external pump set-up.

Turn on the tap, pump runs, water flows.
Turn off tap, pump runs on for a few seconds then stops,
So far so good….

However after a while the pump will run on again for a few seconds when nothing has been opened. Very annoying in the middle of the night.

I've not got any dripping taps.
The drain tap does not look to be dripping
There are no signs of any leaks on the internal pipe-work

There was a bit of a leak where the body plugs into the van but I replaced the o-ring and that stopped. I've also added a bit of silicon lube to teh o-ring so that's a super snug fit with no snagging.

I've tried pressing the button on the inner part of the sensor thing which didn't seem to do anything.
For now all I do is turn the pump switch off at night and when we go out which is probably best practice anyway.

Is this normal behaviour for one of these pumps caused by changed in water pressure through a drop in temperature etc or somethign I can fix. Not a big problem but about to go away for a few days so a chance to have a play.

Our last caravan - Bailey Peg 462 - had exactly that problem (I am assuming we are talking about an internal pump here?) I read up on it - make sure there is at least one unidirectional valve fitted in the pipe, usually between the inlet and the pump, etc etc, and even spoke to Whale who are incredibly helpful.
Without a long story I eventually replaced the pump and it cured the problem. The pressure switch is in the pump and has an adjuster hidden under a label. However the other problem could be that the diaphragm is pierced. If the pump is black and metal (can't remember the name) I have a spare diaphragm assembly here that is of no use to me and to which you are welcome for the price of postage (it is not too heavy.) PM me if you are interested.

 

[Gafferbill]

Hi Mark........from your description you probably need to service the Watermaster Socket.

This socket contains a mushroom shaped diaphragm non return valve which can allow leakage back to the supply container.
This causes the pump to run occasionally to rebuild the pressure .......you will not see a leak because it is happening internally.
This non return valve is susceptible to frost damage if water left in the socket freezes.

Whale do a service kit .......see here.

 

[Mark31415]

Cheers. Is that in the plug that is part of the removable bit or the bit that is fixed to the van?

ie, do I need to do it at the storage place in the cold to the van or can I do it at home with the blue pipe, pump and pluggy bit?

 

[Gafferbill]

........it is in the socket attached to the caravan.

A fiddly job replacing small components.......you have to be accurate and careful to ensure the new valve and the socket seal are seated correctly or you will still have leaks.
Basically you remove 4 Philips screws ....fit new non return valve and reassemble.

 

[bertieboy1]

Hello Mark31415,
If you have a water leak the water pressure gradually reduces until the water pressure switch operates to turn on the pump (when you open the tap the water pressure also drops immediately to turn on the pump).When the water pressure increases (pump running) the pressure switch operates to switch off the pump.It sounds like this is what you're experiencing - a small water leak somewhere - check all your water connections for leakage.

 

[ProfJohnL]

Hello Mark,

From your description, it would seem you have water system controlled by a pressure switch. It works as Bertie and Gaffer have explained.

If the pump continues to do this all night, then It will be due to a leak somewhere, and as you have not found any evidence of a leak, its most likely as Gaffer has suggested.

But you also asked if it it could be temperature related, and yes it can but there is a difference in the number of times the pump is likely to cycle to re build cold water pressure.

This is where it gets technical, if your interested read on otherwise feel free to skip this bit.

The hot water tank is filled from the cold system so it will reach the same pressure as the cold water when the pump runs. The hot tank also has a non return valve, so if the taps are closed, the water in the system is trapped, and it heats up it will expand. the tank will be designed to have a small air cap to give the hot water space to expand.

If no hot taps have been opened, the pressure in the hot system can be up to 50% more than the cold water pressure. If the heater is turned off now, the as the water cools it will slowly return to where it started and the same pressure, which is the peak cold pressure, so the pump won't need to run.

But if a a hot tap is opened, the compressed air in the hot tank forces some hot water out. After a couple of seconds the pressure will equalise with the cold water supply and then the cold system pressure will start to drop until it triggers the pump. If only a little hot water is used, then the hot tank will be pressurised, but only to the same pressure as the cold supply. If at this point the heater is turned off, then as the tank cools over time the pressure will drop below pumps operating point and it will run to reestablish the pressure. Depending on the size of the systems and it configuration this might happen three or four times over several hours, but crucially it will then cease once the tank has stopped cooling.

 

[Mark31415]

I think Prof has nailed it. Sounds like my symptom. Guess I could prove it by leaving the water heater on overnight to see if it still happens.

May get a service kit too just to eliminate that. Thanks all.

 

[chrisn7]

I had this system on my old van and the pump cycling on/off serves as an early warning that there is a leak. This can be very small with just the odd droplet escaping at regular intervals, but its enough for the pump to kick in the end. If you can't see anything try a piece of tissue around a joint - absorption is quick and obvious if damp present.
Despite the need for periodic adjustment, the white Whale pressure switch is reliable - ours was still going after 17 years...
Like you I always turned off the pump when going out.
Oh, and there should be 2 O rings at the inlet, not one, but they need to be lubricated to avoid tearing - they are best replaced annually.

 

[SirRogerFFS]

This issue could also be caused by something as simple as a non return valve just inside the van where the pump comes into the van. This has been the cause of many a similar problem. Simple job takes minutes to do but the price of the non return valve is a bit scary.I must add I had the same problem in our van always nice to pass on to somebody in the boat.( Well Caravan Then )

 

[Whale]

Hi Mark
Please contact our Customer Support Team who will do all they can to assist you with your query. Contact details below.
Tel: 02891 270531 (weekdays) or 0845 217 2933 (weekends)
Email: info@whalepumps.com
Alternatively send me the best number to get you on in a private message and I will get one of our team to give you a call.
Best wishes
Hayley

 

[Mark31415]

Hi All,

Firstly, impressed that Whale take the trouble to respond to Forum posts.

Secondly it does look like it's the hot water cooling down. With it being positively Baltic in Devon over the weekend we had a chance to experiment. The cycling takes place mostly when the hot water tank is cooling down. Once it's fully cold (3am toilet related wake-up), I ran both taps briefly turned them off but left the pump turned on and it didn't cycle again all night or in the morning when the water heater got turned on.

After teh breakfast washing up was done, we got some more cycling which I assume again is to do with the hot water cooling down.

I'll leave everything else well alone...

 

[ProfJohnL]

Thank you for the update.

Don't forget there is a thank you button at the bottom of every post that you can use if feel the post has helped you .