Ideal DHW Flow Switch 172420

The Ideal Heating 172420 is a domestic hot water flow switch for Ideal combi and heat-only boiler ranges. It sits in the DHW circuit and detects water movement when a hot tap is opened, sending a signal to the boiler's control board so the appliance fires and switches to hot water mode. It is supplied by Ideal Heating as a direct replacement for the original switch fitted to Boxer and Europa models.

• No hot water from the taps while the central heating still runs normally
• The boiler fails to fire when a hot tap is opened, or fires only after a delay
• Hot water runs intermittently, cutting in and out during a draw-off
• The pump and fan run on a hot water demand but the burner does not light
• Fault codes or lockouts appearing specifically when domestic hot water is called for

• Confirm the appliance GC number and, where relevant, the serial number against the compatibility list before ordering
• Check the existing switch against the previous number 95000518, which this part replaces
• Inspect the seal or washer at the switch housing when the old component is removed and renew it if it is damaged
• Work on the boiler casing and water-carrying components should be carried out by a competent person