New Toilet/Old Cistern Idea

[TheScullster]

Hi Guys

One of my future projects is an upgrade of the downstairs loo. Currently, this loo is ideal for those more stubborn deposits, as it is a

1970s full flush low level cistern.

Having already been bitten by these pathetic new 6 litre cistern/pan offerings that don't rinse the entire bowl, my thoughts turned to the following. To ensure that we have one toilet that still works effectively/hygienically I was considering:

Retain the existing cistern. Pipe the overflow down the outside of the cistern and into the flush pipe (overflow is currently to external drain and needs to be internal!). Recondition cistern, ie replace all internals. Box/wall in cistern and fit a modern back-to-wall pan.

This way the room can be re-worked to modern spec without loss of functionality.

OK - The Questions

Other than the fact that this does not conform to current regs (but won't be visibly flouting the rules) - Can anyone see anything technically wrong here? Will a modern pan work with an old cistern? Do fittings exist to pipe overflow into flush pipe or would this have to be a home bodge?

TIA

Phil

[Set Square]

Which regs do you have in mind?

Could be a problem. Most modern pans which I've seen are designed to use a close-coupled cistern, and have an extension at the back with an upward-facing hole, and a rubber doughnut to connect to the cistern. I'm not sure how you would connect a low-level cistern to one of these.

I don't know about connecting to the flush pipe, but I have seen overflow pipes - often in hotels etc. - which discharge into the pan. The discharge end is very flat so that they can go over the back lip of the pan and under the seat. Alternatively, if you replace the syphon flush with a push-button flush, this will automatically have an internal overflow.

[Jon]

rather than modify overflow into flush pipe, have a look at Look at BES.co.uk , part number 12718 It's a pan connector to replace existing one that accepts additional waste water ( usually from basin etc ) Connect the overflow pipe into this using readily available adaptors from any decent plumbing merchants.

[<me9]

Don't forget to add a trap in the overfow circuit. I stayed in a guest house one time where they didn't. When the fan ran the smell got worse, rather than better, as it pulled in all the foul air from the drains.

[TheScullster]

Good call Thanks Mr Thumbs

Phil

[TheScullster]

"Set Square" wrote

I may have been wrong in mentioning regulations applicable to existing installations. But, toilet manufacturers are now using Defra guidelines to design cistern capacities and assess flushing performance. As most users of the new offerings are finding, these recommendations lead to woefully inadequate flushing and, just as importantly for people with inquisitive children, bowl cleaning.

Phil

[Set Square]

Ah, I see - the ones about saving water. As you say, with a hidden cistern, you're unlikely to be found out!

It's just possible that, even with a reduced amount of water, you could get adequate clearance if you could dump it from a great enough height. It's really flow *rate* rather than flow *volume* which matters - as witnessed by the effect of pouring half a bucket of water directly into the pan.