BU28414 Seals and Spacers Kit 2750/2900/2910 Upper Hot Water

The BU28414 (0401237522) is the upper seal and spacer kit for Autotrol 2750, 2900 and 2910 series control valves in hot water rated applications. These seals and spacers sit around the valve piston, forming the sealed chambers that direct water through the correct ports during service and regeneration. Hot water use accelerates wear on the elastomer seals, and once they harden or take a compression set the valve can weep, cross-flow or let untreated water slip through, so this kit is stocked by WrekinWater as the fix for a tired upper seal stack.

Technical specifications

Symptoms that mean you need this part

• Water weeping from the valve body or top cap even when the softener is idle
• Hard water bleeding through into the softened supply due to worn seals
• Water running continuously to drain outside of a regeneration cycle
• Discoloured, hardened or flattened seals visible after years of hot water use

Why it fails / why it matters

Inside the valve, the piston moves through a stack of seals and spacers that alternately open and close ports as the valve steps through service, backwash, brine draw and rinse. In hot water applications the elastomer seals are worked harder by higher temperatures, which speeds up hardening and compression set, so they stop sealing fully against the piston bore. Once that happens the valve can allow cross-flow between chambers, letting hard water bypass into the soft supply or water bleed continuously to drain, and because the seals and spacers are matched as a set, replacing the whole upper kit together restores a reliable seal.

Why buy this from WrekinWater

WrekinWater has supplied Autotrol and Structural valve service parts to installers and DIY customers for over 15 years from its Bettisfield, Shropshire base, and stocks seal kits matched to specific valve series like the 2750, 2900 and 2910 so you get the correct upper hot water spec rather than a generic kit. Orders are processed quickly and the business is rated Excellent on Trustpilot, which matters when a weeping valve needs fixing before it causes further damage.

How to fit it

1. Isolate the softener at the bypass valve and shut off the water supply before starting any work on the valve
2. Remove the valve cover and withdraw the piston and upper seal stack assembly as set out in the 2750/2900/2910 service literature
3. Slide the old seals and spacers off the piston, noting their order and orientation as you go
4. Clean the piston shaft and inspect the valve bore for scoring or scale before fitting new parts
5. Fit the BU28414 seals and spacers in the same order, lubricating each with a valve-safe silicone grease as you build the stack
6. Reassemble the piston and cover, restore the water supply, and run a manual regeneration to check the valve seals correctly