i have a close couple toilet i have to depress the handle two or three times before it flushes.i have been told it is the diaphram but how do i replace it? the name on the syphon is derwent macdee
Check with local plumbing shop it may be a type that can be repaired in situ as I think it's a 3 part syphon.
If you have a digi camera take a picture of it and show them. It's also handy to refer to so you know what goes where.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix toilets.