Dear Rabbi Simon,
We need to replace our cooker (oven and stove top), and I was wondering what the best options are from a kashrut perspective. I know a self-cleaning oven is useful for Pesach, but is a catalytic liner acceptable (as oppose to pyrolytic). I understand that with pyrolytic, the grease builds up on the coating, and gets burns away at around 500C. For catalytic, the grease is absorbed into the lining, and then gets burns away at around 200C. Not sure if the catalytic option is ok?
The other questions is whether using an oven with a timer, as a warmer (instead of a hot plate) is acceptable for warming food over shabbat.
Those are my main considerations at the moment.
Any advice will be useful.
I will be brief. The pyrolytic option is the way to go for Pesach and if circumstances require a thorough cleaning (whether for aesthetic or kashrut reasons). The catalytic approach (while less expensive) which is sometimes touted does not fulfil the same role as pyrolytic in halachic terms.
The timer on your oven has potential halakhic uses, however in general the oven does not work effectively as a replacement for your hotplate due to high-tech considerations (thermostat, lights effected by opening and closing, etc) as well as the important halakhic distinction that a hotplate is used for warming and only rarely for cooking. This gives rise to halakhic leniencies vis a vis an oven for Shabbos use. Note that you can use your hot plate in conjunction with an automatic timer (so-called Shabbos clock) for greater energy-efficiency and to limit the heat-generation in the summer (for example).
I hope this is helpful (albeit possibly less helpful than you were hoping ☺)
Rabbi Rashi Simon