Haven't tried yet. Plastic wall is quite thin.
Didn't realise it was a hydrogen water boiler. Looked like my previous boiler so bought without realising it was hydrogen water.
Only setback was instructions n plug was China. Had to translate n buy plug adapter to fit into our 3 pin!
Well packed , fast delivery , works well ,Hot water ready once turn on knob. Good.......
HOT!*SALE NOW* 2-Second Water Boiler And Warmer / Electric Water Kettle/Stainless Steel Water Heater