Pool Alarm Failure

Hi everyone,

Here in France full time at last. Pool opened up and running smoothly.

One problem however. The alarm that was left here does not seem to work properly. I have had the batteries changed and no joy, but I wonder whether I am missing something, like a reset?

The model is an NF P 90307 Sensor Premium and is the type that has a small magnet to set/unset.

These are pretty expensive I understand so want to keep this one going a bit longer if I can.

Many thanks


Hi Roland, As I move around the pool shows of Europe I always make a note of the best products I can find from the plethora of "stuff" on offer. The Geobubble immediately took my fancy as it's a common sense although it did cost a lot in development product and one I have added to my collection of really good and tested products I can offer.

I don't have much preference with winter covers, buying a complying one would seem to make sense. If I spot anything out of the ordinary I will let people know.

Another really good product people should invest in is a pool brush. this pool brush was called the wall whale. It's just a pool brush with a large spoiler that helps keep the brush in contact with the walls and floor. When cleaning the walls, especially the walls, it's easy to over balance close to the edge as you go deeper. The water spoiler takes away that issue so you just apply the push and the wall whale stays in contact with the surface.

A great product but Cash Piscines have them at a bargain price so I shall not be stocking them any more but go get one, you'll love it for around €17

Morning John,

That is interesting advice. I had noticed the billion little blue dots appearing everywhere. The cover has seen better days. I will look out for the geobubble type cover. Is there a recommended retailer for this? Our pool is only 4m x 8m plus a small additional rectangle for steps, so I hope we are not looking at huge money.

We are also going to need a new winter cover in due course. Have you any advice on this front please? Our fixings are too close to the pool we are told , so the necessary tension across the cover cannot be obtained. I can sort this out by drilling new holes further from the edge of the pool, but I think the cover itself is looking too old.

Kind regards


Hi Roland, no one can fault Cash Piscines for some of their incredible prices and they are good on alarms. Their covers are just the regular bubble covers, if you are investing then there are improved versions like the Geobubble, the shape of the bubbles is all curved with no sharp corners which are the weak spot on the others. When they breakdown you get thousands of little plastic disk in your pool which are a PIA. Geobubble doesn't do that and lasts longer especially when put under the supplied cover designed to further protect from UV degradation.

Another little plus, dirt always gets stuck into the corners of a normal bubble cover bubble, the smoother shape of the Geobubble makes it almost impossible for dirt to do that so saving a lot of jet washing!



Hi John,

As with most technical things, there is always more to it than the casual observer realises. I shall continue to closely monitor the pool too see how it behaves. I have noticed that the ph balance improves when it rains, as I assume it is more acidic than our generally hard water.

Will be off to cash piscine to check out the alarms and a new cover. More questions to follow I am afraid !




Hi Roland, Despite me rambling on about testing, pools are basically easy to look after once you have mastered the basics. The issues tend to arise farther down the road when things have been running for some time as the accumulative affect of various chemical additives alters the water and even then things only slightly move off the normal you barely notice it right up to a point when for seemingly no difference the pool goes off and does it's own thing and that's when problems become big enough to require drastic action. All good testing does is alert you to changes earlier so you can take remedial measure before it becomes a problem which is generally more expensive to fix.

Last week I was working on a badly iron stained pool, I remove the iron from pool water not just sequester it like most. This pool has very soft water and a stabiliser (CYA) level of 207ppm yet it still behaves itself which is curious at that level. We had to alter the chemistry slightly to remove the iron and now it stubbornly refuses to behave as the CYA has taken over control, it must have been at the tipping point. The correct thing to do is remove and replace some of the water to lower the CYA level this will also slightly increase the hardness and alkalinity which is also better as it makes the water less corrosive even though the pH was fine. This softening is also caused by the galets as it is by pH- additions but the changes are subtle but over a length of time they do make a difference.

At the end of the day it's about enjoying the pool but knowing a little bit more takes away the angst caused when things don't go right.

That is very kind of you John but sounds as if we need to start again.

Yes it is a bubble cover so will watch t for our bot over eating. We have had a little bit of dust get in with the recent wind and rain, but hopefully the weather is set to improve a bit and I will switch him off.

By the way, seem to be getting on ok with my little water testing kit. I. Ow that it is not cutting edge, but we only have a 4m by 8m pool and the balance seems to be easy to maintain. If things change I will be in touch.

Thanks for all the advice.


Hi Roland, yes I think I would agree about a new one. I tried to get a new sensor for ours which seemed to cure it but a week later it played up again. Yours for spare parts if you want it. PS keep hold of the magnet key they fetch a good price on le Bon Coin.

It's fine to run the pump and robot with the cover on but not to sure why you would need the robot as barely any dirt should make it in unless its a bubble cover in which case your risking the robot eating it, they have quite an appetite for things they shouldn't including their expensive leads.



Hi John

Hmmm none of that sounds too good. I think ours may have died a death. I was not the one that changed the battery, but afterwards there was an orange light and a noise would issue when you ran the magnetic thingy over the cover. Did not set the alarm or disable it though. No alarm when you get in and swim about, just nothing at all.

Now there is no orange light and no reaction to passing the magnet over the top.

Any thoughts other than need a new one? I think that this one is pretty old.

Is it ok to run the pump and th bot when the pool cover is on by the way?

Kind regards


Hi Roland,

What is the symptom? I have to say of all the alarms we fitted when the regulation came in the Sensor premium range were the first to fail, usually just out of their warranty and at that time customer service wasn't. Since then they have been fully taken over by the Maytronics company who were only share holders prior.

We had more success with the Aqualarm, the triangle shaped one which was mooted to be designed by Philips, They have continued to work but on one the keypad failed due to sunlight destroying the plastic. Then the realisation that the return postal address was the same as the Sensor Premium! They refused to send out a new cover with the keypad despite the offer of payment and just insisted the unit was returned for fitting by them (it's only a ribbon cable and plug) but the cost + Colisimo post was ridiculous considering there would not be a new guarantee so accepting the pool alarms are a total loss over 4-5years (Sensor premiums 2y+)

Give it a try and send it back, they wouldn't give out a fixed price for repair and after a lot of arguing eventually sent a replacement so we were not without a unit, BTW they lost ours!! and the unit they sent was dead on arrival.

Sorry it's not a happier story but that's how we got on.

Just noticed that the NF number just refers to the French quality regs so is irrelevant. Sorry.