Non-functioning water softener

[Dr Mike Oxgreen]

Any tips on diagnosing a non-functioning mechanical water softener?

Mrs Oxgreen has been complaining for a few days that the water doesn’t feel right in the shower, and I’ve just used an aquarium test kit on the softened water. Our water is very hard (about 300 mg/l of CaCO₃ equivalent), and I have tested the softened water in the past and found it to be extremely soft - but this time my kit cannot measure any difference between softened and unsoftened water - they’re both off the scale for hardness (excuse the pun).

I noticed that both salt blocks were slightly “stalled”, i.e. they were not sliding down their chamber. I have removed them and scraped off some salt deposits on the side walls, and now they are sliding down properly. However, they were only about an inch above where they should have been.

I have also removed the grid that the blocks sit on, and scooped out a few handfuls of salt sludge from the bottom of the brine tank. I’ve also bailed out a lot of the water and refilled to its normal level.

I don’t know if any of this will have helped or not!

I can’t remember when I last heard the machine doing a regen. The only indication is a sound of flowing water, but I’ve not heard it for a little while. It might be pure chance that I haven’t walked past it during a regen, or maybe it isn’t regenerating. Not sure.

This is a purely mechanical machine. It is not plugged in, and has no buttons or controls at all. Is there a way to force an immediate regen, like there is on an electronic one? Or do I simply have to leave a tap running and see what happens?

Anything else I can try? Any tips gratefully received!

Picture of the machine below…

[GasEngineer]

This does happen when the block stick. Only the bottom 10mm or so rests in the water, so if they stick then the salt is not getting dissolved.

Should be ok in a couple of regens. Or you can force a regen by turning the valve on the top. I'll see if I can find a pic.

ETA something like this at about 45 mins in.

https://www.youtube.com/watch?v=_JGBicsTlEU

Edited by GasEngineer on Tuesday 30th December 11:31

[Dr Mike Oxgreen]

Thanks!

I found a video showing the little white screw valve, which I pushed down and turned, and it started doing a regen (or something, there was flowing water) for about 30 minutes.

It still hadn’t finished doing whatever it was doing after 30 minutes, so I then tried turning the screw back and it popped up again, but it started weeping water from around the screw. So I isolated the feed and output valves (which were very stiff, probably never moved before), and twiddled the screw a bit more.

Now I’ve turned the water feed and output valves back on, and it is still doing a regen (or something), but the little screw isn’t weeping any more.

The water in the brine tank is now below the level of the grid that the blocks sit on. Is this correct? Is that normal during a regen?

[Dr Mike Oxgreen]

Five minutes later, and it has gone silent. There’s now about half an inch of water above the grid that the blocks are sitting on, and the screw isn’t weeping.

Can I, and should I, force another regen?

[Panamax]

You could do it again but I don't think there's any point, it'll either be working or it won't.

Salt blocks should be inserted with their indents facing front and back, not side to side, to suppress sticking.

How old's the machine? When they fail through old age (which they do after, say, 10 years) they tend to fail slowly as the resin in the cylinders gradually gets less capable of doing its job. A sudden failure may be one of the small valves which the flow mechanism has to operate in order to do the cycling correctly. Call the repair man - or just buy a new machine. You can get them off Amazon for not a lot of ££ and very easy to connect.

Bob Sargeant is OK, even if he does drive a Tesla...

[Dr Mike Oxgreen]

Aha!!!

I just ran a softened tap for a while, then collected and tested a jug full.

The test strip now says it’s completely soft, where previously it was above the strip’s testing range. It’s amazing how just one regen has fixed it.

Thanks for everyone’s help. That video was the key to understanding how to do a regen. And I’ve made a mental note to exercise the input and output valves from time to time because they’re very stiff - needed a plumber’s wrench.

So I think it’s likely that the blocks got stuck. I do put them in with the dimples facing outwards, and I usually check that they’re free to move - but they had both hung up a bit.

For anyone with this problem in future, you can force a regen by taking the top cover off and look for a screw valve in the top of one of the chambers. Press it down and turn, and it should start a regen. Turning it back so it pops back up doesn’t seem to stop the regen once it’s in progress though - and if it weeps then try turning it with your screwdriver to its end stop until you find a position where it stops weeping. It took a bit of experimentation but it’s completely dry now.

[GasEngineer]

Dr Mike Oxgreen said:

Thanks!

I found a video showing the little white screw valve, which I pushed down and turned, and it started doing a regen (or something, there was flowing water) for about 30 minutes.

It still hadn t finished doing whatever it was doing after 30 minutes, so I then tried turning the screw back and it popped up again, but it started weeping water from around the screw. So I isolated the feed and output valves (which were very stiff, probably never moved before), and twiddled the screw a bit more.

Now I ve turned the water feed and output valves back on, and it is still doing a regen (or something), but the little screw isn t weeping any more.

The water in the brine tank is now below the level of the grid that the blocks sit on. Is this correct? Is that normal during a regen?

Yes the water level will drop while the old stuff is dumped away and then it will refill.

[GasEngineer]

Good result. !!

[paddy1970]

On purely mechanical softeners like this, regeneration is triggered by water throughput, not a timer, so there is no “force regen” button; if it has stopped softening, the usual causes are a stalled or worn meter/turbine, a seized valve, or a brine issue rather than anything electrical. With the salt blocks now moving freely and the sludge cleared, the next thing to try is running a high, continuous draw (for example an outside tap or bath tap fully open for 20–30 minutes) to see if it initiates a regeneration cycle, which you should hear as sustained water flow to waste. If that does not happen, the internal metering mechanism is likely stuck or failed, which is common on older mechanical units and means it will never trigger a regen no matter how much water you run. At that point it is usually a strip-down/service or valve replacement job rather than user adjustment, and given the hardness you are seeing, the resin will already be exhausted until regeneration is restored.

[Dr Mike Oxgreen]

Yes, I’m trying not to celebrate just yet, until I’ve heard it do an automatic regen.

My worry is that the salt sludge I found implies that the water in the brine tank was actually saturated with salt, so why did the regen not work? Possibly because the machine didn’t actually attempt a regen, due to a failed metering mechanism.

Or maybe that sludge was the accumulation of impurities from quite a few salt blocks over the years. I’ve never cleaned it out before today.

At least I know how to force a regen of sorts, and it certainly has restored the softening action - for now at least.

I’ve drawn pencil lines on the walls of the brine tank where the salt blocks currently come up to, so I’ll know if they go down over the next week. I’ll also keep testing the water and be on alert for the sound of flowing water.

[Panamax]

Dr Mike Oxgreen said:

At least I know how to force a regen of sorts, and it certainly has restored the softening action - for now at least.

Exactly, you've done the right thing by clearing the blocks and triggering the regen button. There nothing else on these machines. If it was still not working you'd be into strip-down to examine the fiddly bets, which is best left to a professional familiar with the gear.

As mentioned earlier, these machines "age" in the sense that the resin in the cylinders gets tired. That doesn't matter much until you find your water gradually fails to soften as effectively as when the machine was new. Once that happens there's no point calling an engineer for an old machine, you just replace it. If all the plumbing is already in place (like yours) it would be no more difficult than replacing a washing machine.

[GasEngineer]

paddy1970 said:

On purely mechanical softeners like this, regeneration is triggered by water throughput, not a timer, so there is no force regen button;

Many of them do actually have a forced regen facility. It basically winds the valve that slowly ticks round to the regen phase straight round to the regen position.