Looking for a central London hotel for about 100 pounds a night, 2 twins or 2 double beds.
What neighborhood do you consider central London?
Russell Sq through to Kensington area.
A regular poster on the London Forum on Trip Advisor named TexScott has developed this list of 'Budget Hotels' for London, which he keeps updated. You might find it helpful. https://docs.google.com/document/d/1HeA7aE16Ocbq89n5Fxjxx0v61kLlsU3j8S4mk8Uqfeo/edit?hl=en_US&pli=1
Try Lancaster Hall - www.lancaster-hall-hotel.co.uk - It is just north of Hyde Park. All rooms have 2 twin beds. It is 87 pounds. They have a pretty good breakfast. We have stayed there several times and will be again next month. Have fun.
Try the Penn Club then.
Go to www.londontown.com with your dates and see what turns up. Also, www.laterooms.com usually has some good deals closer to the date of your trip.