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Alpha Flow Switch Domestic Hot Water 1.035365

Alpha

Alpha Flow Switch Domestic Hot Water 1.035365

At a glance

  • Part type: Domestic hot water flow switch
  • Also known as 1258745
Manufacturer part no.
1.035365
Showing prices

£55.44

£46.20 ex. VAT · VAT at 20%

In stock
Cut-off passed — dispatches next working day
Not certain it's the right part? The technical team verifies fitment before dispatch — no charge, and it stops a second trip.Call the technical teamSend a technical question

Same-day dispatch

Ordered by 4pm Mon–Fri, 10:30am Sat.

30-day returns

Unused, in original packaging.

What it is

The Alpha domestic hot water flow switch is a safety component used across a wide range of Alpha boiler platforms, including InTec, InTec2, Eco, InTec ERP, E-Tec and Evoke. A sensor sits inside the heating or hot water pipework and detects whether water is actually moving through the system. The switch reports that flow condition back to the boiler's printed circuit board, which uses the signal to decide whether the burner is allowed to fire.

Signs this part needs replacing

  • The boiler fails to fire on a hot water demand even though water is running at the tap
  • Repeated lockouts or ignition faults that clear when the appliance is reset
  • The burner attempts to light when the system is low on water or running dry
  • Intermittent hot water, with the boiler cutting in and out during a draw-off
  • Fault codes or diagnostic readings on the PCB pointing to a missing or erratic flow signal

Before you order

  • Check the GC number on the appliance data badge against the compatibility list to confirm the correct variant
  • Confirm the part number currently fitted, as several earlier numbers are listed for this switch
  • Isolate the electrical supply and close the water isolation valves before removing the old switch
  • Have a replacement seal or gasket to hand if the existing one is disturbed during removal

Not sure which part?

Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.