I am planning to get a new WC for the downstairs cloakroom in our house. We have two possible WCs in mind. Both have a cistern with a lever rather than a push button on the middle of the lid, which is what my wife and I prefer. I am concerned about the siphons supplied with the cisterns. I have written to the manufacturer of each WC but have not yet received a reply. But I strongly suspect that the supplied siphons will not be of the type that come in two parts, allowing the bell housing assembly to be removed from the siphon leg without having to drain the cistern and remove the cistern from the pan. With this type of siphon, changing a broken diaphragm washer becomes a 15 minute DIY job.
So, I am expecting to have to replace the supplied siphon with a Wirquin Macdee Metro Rapid siphon. The problem then is how to select the shape (of the bell housing) of the siphon (oblong, square, D-shaped or round) and the size of the siphon (6/7 sizes depending the shape, from 7.5” to 10.5”). Does anyone have any experience of how to select the right shape and size for a specific cistern?
Intuitively, I feel that, when you unscrew the nut to remove the bell housing assembly of a Metro Rapid siphon, the exposed top of the siphon leg should be above the waterline so that water does not start to flow down the siphon leg into the pan. So, one question that comes to mind is, knowing the recommended depth of water in the cistern, how do I determine the optimal size of Metro Rapid siphon for that cistern?
I have had some correspondence with Wirquin on this issue, but they have been particularly vague in their replies.
(PS. I know that there are other siphons on the market like the Metro Rapid - the Dudley Turbo 88, for example. But we have a Metro Rapid in another WC in our house and it works very well.)
So, I am expecting to have to replace the supplied siphon with a Wirquin Macdee Metro Rapid siphon. The problem then is how to select the shape (of the bell housing) of the siphon (oblong, square, D-shaped or round) and the size of the siphon (6/7 sizes depending the shape, from 7.5” to 10.5”). Does anyone have any experience of how to select the right shape and size for a specific cistern?
Intuitively, I feel that, when you unscrew the nut to remove the bell housing assembly of a Metro Rapid siphon, the exposed top of the siphon leg should be above the waterline so that water does not start to flow down the siphon leg into the pan. So, one question that comes to mind is, knowing the recommended depth of water in the cistern, how do I determine the optimal size of Metro Rapid siphon for that cistern?
I have had some correspondence with Wirquin on this issue, but they have been particularly vague in their replies.
(PS. I know that there are other siphons on the market like the Metro Rapid - the Dudley Turbo 88, for example. But we have a Metro Rapid in another WC in our house and it works very well.)