BoilerTroubleshooting2026-02-26
Shower Goes Hot and Cold with a Combi
Fluctuating shower temperature points to scale, low flow or a flow-sensor fault.
A combi shower swinging hot and cold usually traces to flow and scale issues.
Common causes
Scale in the heat exchanger, low water flow, or a faulty flow sensor make the combi cut in and out during a shower.
What to do
Clean the showerhead and inlet filter; persistent swings need descaling or a flow-sensor repair.
Key takeaways
- Clean showerhead and filters
- Scale causes temperature swings
- Low flow can trigger it
- Descaling often helps
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