Passover- Koshering the Dishwasher, Oven, Tables, Countertops, Microwave, Stovetop, and Sink
We present here a practical guide for preparing the various parts of one's kitchen for Pesach:
1) Dishwashers: One prepares a dishwasher for use on Pesach by running a complete cycle before Pesach with the dishwasher empty. Detergent should be poured on the racks before the cycle is run.
2) Ovens: An oven with a self-clean feature is prepared for Pesach by running a complete self-cleaning cycle. If an oven does not have such a feature, then one should thoroughly clean the oven's exterior and interior with "Easy Off" or some other chemical-based cleaning agent, and then run the oven for an hour on its highest setting.
3) Tables: A table that has been used with Hametz should be cleaned and then covered with a tablecloth. One should pour hot water over the table first. One may then eat on the tablecloth throughout the festival of Pesach. When cleaning the table, one must ensure to remove all residue dirt and substances from the surface and from any cracks or holes in the table. (See Chazon Ovadya page 159.)
4) Countertops: Formica, stone and marble countertops can be prepared for Pesach by pouring boiling water over them. One should boil a kettle of water, wait for it to whistle, and then immediately pour the kettle's water over the countertops. Some have the custom to then cover the countertops after pouring boiling water over them. (See Chazon Ovadya page 160.)
5) Microwaves: The question of whether and how a microwave oven can be prepared for use on Pesach is a complex one. It is therefore advisable to cover all foods one places in the microwave on Pesach with plastic wrap. Ideally, one should cover all foods placed in the microwave during the year, as well. According to some authorities, one can prepare a microwave oven for use on Pesach by adding some soap to a bowl of water and then heating the water in the microwave until it reaches a boil. The steam then expunges the Hametz from the walls of the microwave. Still, it is proper to cover all food placed in the microwave during Pesach, even if one followed the aforementioned procedure.
6) Stovetops: To prepare a stovetop for Pesach, one should, after thoroughly cleaning the grates, make Hag’ala on them or pour hot water over them. Furthermore, one should pour hot water over the stovetop after thoroughly cleaning it. (See Chazon Ovadya page 137.)
7) Sinks: One should prepare his sink for Pesach by pouring boiling water over it from a kettle three times. Chacham Ovadia Yosef, in his work Chazon Ovadia (Laws of Pesach, p. 151), rules that this is effective even for porcelain sinks, despite the fact that porcelain utensils generally cannot be "Koshered" for Pesach. The exception made for sinks stems from a number of different factors. Firstly, it is uncertain whether the sink had been used with water hot enough to allow the sink to absorb particles of Hametz. And even if this did occur, soap is normally used when utensils are washed in the sink, thus rendering any absorbed particles "Pagum" (foul-tasting), which Halacha treats with greater leniency. Finally, any Hametz absorbed in the sink was absorbed when Hametz was still permissible for consumption, which allows us to remove the absorbed particles through the process of Hag'ala (immersion in boiling water). Some people have the admirable practice to place a grating on the bottom of the sink so that the utensils do not come in direct contact with the surface of the sink, even after boiling water has been poured over the sink.