Cam Shaft for 255-700-860 Camshaft Standard Black 1235353

The Autotrol 1235353 is the genuine standard black camshaft for 255-700-860 series Logix water softener valves — the shaft that indexes the piston stack through each regeneration stage. It's the part behind searches for "Autotrol valve stuck", "Autotrol camshaft replacement" or "water softener won't regenerate fully". Genuine Pentair Autotrol part, stocked by WrekinWater.

Technical specifications

Symptoms that mean you need this part

• The valve gets stuck partway through a stage — for example, stalled in backwash and unable to advance
• The drive motor runs continuously without the valve ever moving on to the next step
• An audible grinding or laboured motor noise during regeneration
• A regeneration cycle that takes far longer than usual, or never completes

Why it fails / why it matters

The cam surface wears with age and use, but a camshaft more often shears or cracks because something downstream — usually a scaled or grit-bound piston stack — has been binding and putting excessive load through it. When that happens the motor keeps trying to turn the shaft, but the shaft can no longer properly index the valve, so the whole cycle stalls.

Why buy this from WrekinWater

A stalled Logix valve is one of the more stressful faults for customers to diagnose alone, and it's a call we field often — 15 years of talking Autotrol owners through exactly this fault, so if you're not sure whether it's the camshaft or something further downstream, get in touch before you order. Rated Excellent on Trustpilot, UK stock.

How to fit it

1. Bypass and relieve pressure before starting.
2. Remove the drive/motor assembly to access the camshaft.
3. Withdraw the old camshaft, noting its index/orientation mark.
4. Fit the new camshaft the same way round and reassemble the drive unit.
5. Run a full manual regeneration through every stage, checking the valve advances cleanly at each step and the drive indicator lines up as expected.
6. Because a worn camshaft is often a symptom of a stack that's been binding, it's worth checking the piston stack for scale or damage at the same time — replacing the shaft alone without addressing the cause risks a repeat failure.