Search the Community

I'm proposing that our downstairs loo will have a fixed window to stop people opening it and messing up the MVHR. I've been looking at the duofresh cistern from Geberit - has anyone installed/used one of these? Do they work?

Hi, I went downstairs last night just before going asleep and noticed a damp patch on the kitchen ceiling. I got on a chair and it was definitely wet and covered a a few m2 area. Water was bubbling the paint on one of the walls. I turned off the mains and headed upstairs to figure out what was wrong. The area under the master bathroom toilet cistern was wet. I opened the lid and saw the water level was higher than normal. Not so high as to flood out of the top of the cistern but it was over the height of an overflow pipe. The pipe was "crimped" at the top but when I checked the exit point there was nothing plugged into it! So it just drained all over the floor of the bathroom. I've been living here for years but never realized this was put there by the builder decades ago until now. The reason the water level rose more than normal is that the ball cock was loose and allowed water reach a higher level than usual before it cut off. I've strapped the ball cock in a closed position and I'm planning to replace all 3 sets in the house (9l cisterns) with a more suitable dual flush alternative. This is the only cistern with an overflow, albeit one not going anywhere....! So, What's the best way to deal with this overflow pipe? Cap it top and bottom, remove or just plug the outlet where it exits below the cistern? Finally, any advice re: water damage to kitchen ceiling and wall? Do I let it dry out or at what point do you pull things down and re-plaster? I've downlighters so I'll need to isolate them until things dry out. Thanks

It has been a while since I posted and things are progressing, so expect a flurry of posts in the next few months as things are decided before we go to contract, however I have been working on some minor detailing. I have decided that I want to extract toilet smells directly from the pan (see JSHarris blog part 32) I have 6 toilets in the house, in 3 pairs (see the plans on blog 02-The Planning Saga) so can use 3 extract runs, one to each pair, the simple bit. I then need to work out how to connect to the MVHR system and the toilet cistern. The MVHR ducting will be Hybalans+, thought the design/supply/install is still be to sorted out. So I have 3 issues to work out: 1 connecting to the cistern, 2 connecting to the MVHR, 3 connecting the two together. Connecting to the cistern. After much research looking at low flush toilets and attempting to get information from suppliers (as soon as you go for non-standard ideas they all clam up) I discovered the Geberit Duofresh with build in odour extraction and started enquiring with Geberit about getting the connecting pipe from cistern to pan and using it on a standard cistern. Trying to get this bit. The issue being that the bit I want is not available as a part and is solvent welded to the cistern, however after much toing and froing of e-mails and finally a call from the technical department it was agreed that by using the Duofresh cistern (available without the filter and fan unit) I could cut through the pipe and connect it to the MVHR system. The plan is to cut the vent pipe (it is 50mm) and put on a solvent weld joint with reducer and 40mm push fit adaptor (reason for 40mm push fit later). I was also planning to seal up the feed into the cistern (vertical pipe) however this is square post the transition bend so not going to be so easy (can’t use a 50mm plug) so I may end up just filling it with expanding foam to seal it. I have decided on the Geberit cistern as the ability to service them once installed appeals and the Duofresh cistern is only about £10 dearer than the standard cistern. Connecting to the MVHR. I then needed to work out how to connect the pipe to the MVHR system, the pipe coming from the manifold will be either 92/75 or 75/62 (external/internal dimension) and connect it to two 40mm pipes. I then realised that soil pipes are 110mm standard and the vent terminals are between 100 &125mm so there was some potential there. My solution (still to be tested) is to use a vent terminal adaptor onto a solvent weld pipe, my reasoning as follows: The 110mm soil pipe has an outside diameter of approximately 110mm and the solvent weld socket has an outside diameter of 121mm. The straight vent connector has a diameter of 125mm, the 900 one 118mm, however the vent inserts show a diameter of 114mm, so I suspect the 125mm is an external and the 118mm internal. The straight vent connector has a diameter of 125mm, the 900 one 118mm, however the vent inserts show a diameter of 114mm, so I suspect the 125mm is an external and the 118mm internal. I should be able to connect the vent terminal adaptor over the plain pipe with a push fit sealing ring on it and solvent weld a plug into the other end. Then insert two 40mm push fit boss adaptors into the bosses on the pipe. I should now have an adaptor that connects the 92/75 MVHR pipe to (1-4) 40mm push fit waste pipes. Connect the MVHR adaptor to the cistern connector. With 40mm push fit sockets on both ends it is a simple job to connect up the two ends either with flexible 40mm pipe or rigid with a length of flexible 40mm pipe at each end: So now I have a plan to connect the toilets to the MVHR. The Geberit parts number is: 111.353.00.5 (Geberit Duofix frame for wall-hung WC, 112 cm, with Sigma concealed cistern 12 cm, for odour extraction with recirculating air) The normal cistern is: 111.383.005 (Geberit Duofix frame for wall-hung WC, 112 cm, with Sigma concealed cistern 12 cm, wall anchoring and connection bend)