Modifying Washing M/C Waste Standpipe For Combi Condy Line?

20 Mar 2006
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United Kingdom
My combi boiler was installed last November but the condensate line goes outside into the drain pipe through the wall. It was mild last winter but I would rather have the condy line going into the washing machine waste somehow as there is a heater in the garage below the waste should it get really cold. If you look at the picture the combi condy line is the lagged line to the right. I was wondering what is the easiest way to modify the 40mm waste to accept the 22mm condensate line please? Thanks for any advice, greatly appreciated.

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Cut in a 40mm compression tee on the wash mac upstand. Then pipe across in 40mm to condensate pipe.

Thanks for the speedy replies guys. I've got it figured now from both suggestions. Thanks :D
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Thanks for all the replies, much appreciated. Assuming that I went with a 40mm T and then across to the condensate line then up under it using a 40mm elbow. Does the waste pipe need a reducer to put the condensate line in or is it ok just sitting inside the 40mm waste as I am guessing that there is no pressure there. Thanks.
If you cut it into the vertical leg of the standpipe make sure you've got a CO alarm in the room. I would also put an inline trap in the condense pipework. I re-commissioned a boiler not long ago where the house had been empty for a few months, the trap on the standpipe had dried out and i got exactly the same analyser readings from the boiler flue and the end of the standpipe. Technically its part of the flue system so BEST advice is to get a RGI to fit/test it. Wouldn't cost much (you supply gear) and sleep easy.
the trap on the standpipe had dried out and i got exactly the same analyser readings from the boiler flue and the end of the standpipe

You'd get the same readings if the standpipe trap was full. The reason why you got those readings is because the condensate trap on the boiler had dried out. But good precaution really as like you said the condensate pipework is part of the flue system.


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