How to Replace a Scale Reducer (UK)
Fit a polyphosphate or magnetic scale reducer on a combi boiler cold inlet. Fernox, Kinetico, Sentinel.
FernoxKineticoSentinelSalamander
Types
- Polyphosphate — dosed chemical, replace cartridge every 6–12 months.
- Magnetic — permanent, no consumables (efficacy debated but recommended by Fernox).
- Electrolytic — mains-powered, prevents scale adhesion.
Fit
15 mm compression on cold mains before the boiler. Isolation valves both sides for easy service.
Frequently asked questions
- Does a scale reducer protect a plate heat exchanger?
- Polyphosphate — yes, if replaced on schedule. Magnetic — some effect. Fitting a proper softener is the only guaranteed long-term fix.
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