• Looking for a smarter way to manage your heating this winter? We’ve been testing the new Aqara Radiator Thermostat W600 to see how quiet, accurate and easy it is to use around the home. Click here read our review.

Unusual waste issue with air con combining waste pipe in an old home

Therein lies part of the issue, the 40mm waste pipe is, I suspect, filling very rapidly when the Washing machine and/or Dishwasher discharges, and once full, it needs to start displacing air as currently it's a sealed unit.

That in itself is wrong, needs air behind the water, so an air break is needed above the discharge point.
I can't fault your logic, but the OP has not seen fit to disclose the details of the (near?) horizontal portion of the waste pipe. With a constant and correct fall air from the main drain (4" or so) will flow up and behind the slug of foul water from the washing machine. The OP probably does not have this, so other devices need to be introduced to alleviate the problems of 'spurting' (poor discharge flow), and foul smell (open vents in the room).
 
If the waste pipe is clear, fitted with an adequate fall, and standpipe used as designed, then there should really be any issue with odour. My washing machine discharges into a standpipe behind it, and has done for over 10 years now, never had an issue with odour.

My suspicion still remains, the OP's waste pipe is either blocked, or is badly supported so has a dip in it somewhere, but until they come back with some answers, it's all pretty much still educated guesswork.
 

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top