How to Power Flush a Heating System (UK)
Full chemical power flush of a UK wet central heating system. Chemicals, machine, verification and inhibitor.
FernoxSentinelKamco
When to flush
Before fitting a new boiler. When rads are cold at bottom, hot at top. TDS above 500 ppm or magnetic filter catching heavy debris monthly.
Procedure
Isolate boiler. Connect flush unit across flow/return. Dose Fernox F5 cleaner. Circulate at 40 °C for 2 h. Flush individual rads with reverse flow. Drain, refill, inhibit with 500 mL Fernox F1 per 100 L.
Frequently asked questions
- How often should a system be flushed?
- Every 10 years, or when installing a new boiler. Annual test of TDS confirms condition.
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