Hi Been to this today.
Problem is that if you select drain only, the pump will work for about 5 seconds then the light on display goes back to ready.
If you select spin the machine works fine pump working all the way through.
I checked the carbons and they were low but still ok as customer said she has had a problem getting the machine to spin.
Cheers, Ray
Drain only ending after a few seconds sounds to me like there’s an earth leak on the heater? I would megger that heater, check that the air chamber isn’t clogged and replaced the carbons whilst your at it! 🙂