My water softertener, a Kinetico 2020c, has developed a leak. The inlet/outlet manifold gubbins has a set of 4 o-rings that seem to have deformed over the years, and now no longer hold back the water pressure, so leak. Not too much, but enough to be a pita.

I’m looking to replace the o-rings, which is a pretty straight forward job. But I can’t find much/any info on the spec of the rings themselves. Kinetico are typically useless, a closed shop, that effectiviely means to get anything done, you have to have the unit serviced, which last time came in at >£250. I think the o-rings are probably worth approx £1, so looking to source and fit diy. Just can’t fully work out what to get and where from.

Anyone got any insight or suggestions?

Can you measure the groove dimensions that the o-rings sit in? Prepol have a good free-to-use o-ring design tool on their website (need to register for a free account first I think), that should get you dimensions, then all you need is the material? Polymax are then a good option for small quantities of replacements.

I bought a whole kit of o-rings from toolstation or screwfix a few years back. One of the sizes has always done the job for me!

I’m not sure I have the capability to mearsure the grove. But think I’ve identified them (via google) as 15/16th internal and 1 and 3/16th external. So that’s my working assumption at the moment. Happy to buy a few, if cheap enough, and if they aren’t correct can rethink approach.

Actually, having thought about it, those dimesions are way off. Just measured, it’s more like 1 and 2/16ths internal. The search continues…

Ok, a bit more than a quid but nowhere near £250 if it contains the bits you want

Kinetico / WinterHalter 2020c Water softener service kit. Fixes common problems. | eBay

There’s a few other options if you google Kinetico 2020c service kit

That kit only contains the interal seals, for the softener head valve, but not the connecting parts. But, now having looked at ebay for the second time, these are the o-rings I’m looking for. I’m not after the adaptor, and will have to by two sets, but still cheaper than a full service. This is the cosest I’ve come yet.

https://www.ebay.co.uk/itm/174265729784?hash=item28930c02f8:g:4YsAAOSw5bdeqXpN&amdata=enc%3AAQAHAAAAsDJnccFEUSIqFLDXXO%2FNvkMEX2p4hS8F7vYEXouJh%2BzG0qMTZpiKAp9Oi5v4bngyTkzAzIo0yx3UVM3tj1%2BPT85IcfkjrZCv89y1dWH3VT1Q2%2BIAN62JrD2USRBGDtpUqN%2BnGhbS18C1elSNYkFVPGYWkQx7O48loC0oaXtfb8UF2z5koqzW6nQc92mlXjKF314BPgFivkEsPDe0T%2F2sW9oueekUFKLB2tOnB2y5pr%2Bg%7Ctkp%3ABk9SR7Kxv6DGYQ

double post.

How  by old is the unit itself ? They only have a 5yr life allegedly more from the fact that they get full of rubbish and a bit manky

The softener is over 15years old. But I’m not too unhappy with that. I’m not convinced about them getting manky, I’ve seen no evidence of that, and (aside from the o-rings) seems to be in perfectly good order.

O ring measurements are bore size and cross section. Ideally you slide them down a measuring cone to hold them in a circular shape when measuring.

If they look an oddball set of dimensions then they often relate to a BS number size so worth doing a search on your dimensions (in mm) to see if there is something near.

For top quality hydraulic O rings I buy direct from Fairway Seals. There are different materials (nitrile, viton etc) and different hardnesses. Generally they are often 70 shore as std  (but I need 90 for 280 bar hydraulic stuff which won’t apply to you).

I’ve rebuilt radiator taps using red silicone ones before as they handled heat better.

@mick_r, nice one. Is that internal or external bore? I can probably measure the external. The internal is difficult as it’s a grove, and my mic blades dont bottom out in it. Cross section is measureable too.

Internal bore and cross section of the O ring itself. If it has flattened then you need to measure cross section in both directions and guesstimate (but use the BS number as a guide to what it could??? be). Square cross section O rings also exist…..but I doubt it in your application.

The groove dimensions have an allowance / gap for the ring to squash into when assembled, but the inner diameter is usually pretty close to the internal ring bore – rings aren’t generally stretched when sat in the groove. I’m not back in work until next week but I do have some tables that could estimate the likely O ring size from groove / shaft etc dimensions.

@mick_r Right, so I’ve finally managed to find a vernier that fits the groove. The groove internal is 29.2mm. The o-ring cross section is 2.5mm.

Looking at Fairway Seals, nothing quite matches. Nothing quite matches exactly. Super cheap though, so might well get a few packs and see how they measure up in reality.