Problems with float switch in header tank

[lardconcepts]

Came home to find the kitchen flooding and water pouring through the ceilings between the loft and the kitchen, via the bathroom.

Turns out the float switch, which controls the pump that brings water from the well, had stuck, AND the overflow pipe had the remains of some kind of nest in the end of it (looks like wasp, no occupants!).

And then I worked my way through the horror show that the previous owner had left for me.

It's some kind of Heath-Robinson thing perched on bits of wood, counterbalanced with a weight!

Looks like there's a float switch already there, presumably it doesn't work, hence not being used.

How it works is that a switch passes 230v up to the float switch, that makes a contact, and a simple relay is triggered, turning the pump on. Everything is at mains voltage.

Here are some horror pics:
https://photos.app.goo.gl/18RiWUcP5Hz9dCo29

I want to replace both the float switch for something more reliable, and I want to put a timeout relay that will never pump for more than about 10 minutes.

If the relay is triggered on for more than 10 mins, it should latch off and not respond unless reset manually (and preferably beep so I know it's been triggered!).

The idea being that even if the float switch AND overflow fails again, the most overpumping that will happen is no longer than the time it takes to fill the tank between the "on" trigger point and the top of the tank. So, any ideas for a 230v replacement float switch and/or relay?

(Before anyone freaks, the water is 1nm particle and UV-filtered before drinking!)

 

[JohnD]

You're obviously very annoyed, and it wants tidying up, but to prevent future floods, the first thing you should do is fit a better overflow pipe in a good large size, discharging where it will be apparent. Modern ones are resistant to insects getting up them, I don't know how a bird could do it. If the tank has a good lid it will prevent anything getting in.

BTW when I've had bad overflows, the electricity went off as soon as it reached an RCD protected circuit. I see you have a local RCD, are the sockets in the house protected?

I wonder if you could also fit an ordinary ball valve, with a pressure-release outlet in case the pump didn't stop?

 

[just pumps]

Jeeze, haven`t seen one of those for many a year and the counterbalance is an original piece not an add on I might add. Can`t help with the timer aspect of things but I would either clean everything and grease where necessary, replace the overflow pipe with a bigger pipe or replace with a submersible pump with a float, a high water level remote alarm can be added.

 

[lardconcepts]

Thanks both. Good ideas there.

I see you have a local RCD

Well, I do in fact have an RCD, but what made you think that from the pics, given it's about 30 feet away on the dist. board? It did indeed trip when the light fittings started dripping, however, the lighting circuit is separate so didn't cut the pump. Not too good to rely on.

a submersible pump with a float, a high water level remote alarm can be added.

I like the idea, but I think that's adding more complexity again?

 

[just pumps]

Thanks both. Good ideas there.

Well, I do in fact have an RCD, but what made you think that from the pics, given it's about 30 feet away on the dist. board? It did indeed trip when the light fittings started dripping, however, the lighting circuit is separate so didn't cut the pump. Not too good to rely on.

I like the idea, but I think that's adding more complexity again?

These things don`t last forever without some care, the increased overflow pipe where as JohnD said you can see it takes away the need for the timer and the alarm.

 

[JohnD]

What is the RS thing?

 

[just pumps]

Switch gear I think.

 

[bernardgreen]

There might be a suitable switch in the Kari range of float switches. Depends on the size of the tank.

https://www.kari-finn.fi/index.php/En/products/float-switches/miksi-kari-pintakytkin-en

There is UK company that sells them.

They have three sensing levels . START. STOP and ALARM ( over filled ) The alarm switch is islated from the start / stop switches and can be connected into a separately powered alarm system if needed.

EDIT the link shows a float switch in tank emptying mode, they work just as well in tank filling mode.

 

[endecotp]

Fit two level switches (of different types) and two overflow pipes!

Here are 889 float switches to consider:!
https://www.digikey.co.uk/products/en/sensors-transducers/float-level-sensors/521

 

[lardconcepts]

Thanks for the links to float switches, everyone

What is the RS thing?

A very ancient 240 relay. Must be from about 1990 ish...

 

[mattylad]

What does the tank supply? Does it feed showers, bath? Or is it just for drinking water?

 

[just pumps]

What does the tank supply? Does it feed showers, bath? Or is it just for drinking water?

What is the relevance of that question, it is a tank with a float and a pump.

 

[MeldrewsMate]

You already have an electrical float switch installed through the side of the tank, if working this can be used as the overfilling alarm (system failure alarm).

Moving on to the general control of the pump, use a float switch to energise two items, a control relay to start/stop the well pump, and a timer relay to power your 'running too long' alert sounder/lamp. Set the timer to your nominal 10 minutes, so it will alarm if the pump runs longer than 10 mins. Additionally it would be easy to add another timer relay to alert you in the case of a failed/tripped well pump ie alarm if the pump is demanded for longer than x minutes but the normal water level hasn't been reached.

As an additional belt and braces consider filling the tank via a traditional float valve (ball-cock) and set the pump activating switch at a slightly lower level than the ballcock to avoid squeeking.
The control wiring for this is relatively simple, but I don't have the techie ability to draw it electronically and post it here. Perhaps someone else could assist with that.

Good advice already given wrt upgrading the ineffective overflow pipework.

 

[Echo the husky]

I quite like those float switches, and you get to play with the mercury in them when they are no longer needed!

 

[mattylad]

What is the relevance of that question, it is a tank with a float and a pump.

The time for supply, if it supplies showers and baths then 10 minutes may not be long enough - I know my daughter easily takes twice that long in the shower.

Additionally, if someone burns themselves in the kitchen then medical advice is to run it under a cold tap for 20 minutes (ISTR) which will be reduced if they can only use the tap for 10 minutes.

Does it get used to water the garden? and so on.