Can't find plumbing problem?

Hi,

I need some advice regards my plumbing. I have just moved into a brand new 2bed apartment on the first floor and I have been having problems with the plumbing. We are only in the apt for ~3 weeks and the appliances are brand new Zanussi.

Firstly when we installed the washing machine we knocked off the hot water supply (i.e. there was two hot and cold water available for the w-machine, but it only takes cold) and turned it on. That let a lot of water into the apartment and the two downstairs!! Luckily there wasn't too much damage, a de-humidifier and some new paint down stairs solved most of the problems. Anyway since then I have been keeping a really close eye on the plumbing in the kitchen.

So my real problem occurred yesterday, I woke up yesterday to find that the overflow pipes behind the dishwasher and washing machine had overflowed. This had also knocked off the trip switch as the overflow pipe is directly above a plug-socket (is this normal?). The dishwasher and washing machine were not on at the same time, even though I would have thought that proper plumbing could handle this, at the same time I could understand that this might overload the plumbing.

I called the builders/developers and they sent out their gofor and a plumber. When they came out they found that the sink was not draining properly (sink, dishwasher, w-machine all join together just to the right of the sink behind the dishwasher). I didn't know whether that was cause/effect of my leak, but proceeded to get grilled/lectured over not putting stuff down the sink. I am fully aware of this, I take at least the usual precautions, i.e. scrape food into the bin, and when I do have to clean the grill tray (not often) I heat it and use paper towel to scrape into the bin etc etc.

So after an hour and a half of pouring boiling water down the sink, banging the pipes and trying to get a kind of spring thingy through the pipes - the water was draining perfectly even when the taps were on at full blast. So they were convinced that I had put something down the sinks, fair enough, I thought it wasn't outside the realms of possibility.

When they were gone I ran the washing machine on its own, still pulled out a little from the wall, and about 3/4 of the way through the cycle the waste pipe overflowed again (behind both machines). So I got the builder and plumber back.

This time the sink was draining perfect, again they didn't find any problems, but when the w-machine ran again it apparently was fine (I had to leave for a few mins). So now I am at a standoff with the builder. They say we can find nothing wrong, hence, we have fulfilled our responsibility. I say they have not found the problem, hence, the problem is not solved.

So what I would like people's opinions on is whether I am correct in the following:

• The problem is not with the dishwasher machine or washing machine, the leak is due to the waste pipe backing up.
• Proper plumbing should not get blocked with a mere three weeks of careful use.
• Proper plumbing should in theory allow the two machines to run at once.
• If I have not blocked the pipes then the plumbing is not up to scratch, or, the builders blocked the pipe. In this case it would be their responsibility to fix the problem.

Also does anyone have ideas for what we should do next?

I agreed with the builders that I would monitor the situation carefully and inform them of any problems. I also told him I would be getting a second-opinion on the plumbing. What should I get my plumber to check, is there any tests people could recomend?

Furthermore I was intending contacting my solicitor to see where I stood, is there something I should instruct the solicitor to do?

As always brevity is not my gift.

Please help!!!!

Tricky one this, presumably your 2 appliances and 1 sink are draining to a single 40mm waste which in turn is discharging to a 110mm soil stack; this stack is shared between you and other apartments above and below you.
It is possible that during peak times the 110mm stack could be running at full bore (when other apartments are using appliances, running taps etc) thereby causing momentary backflow of water. But even at that washing machines or dishwashers don't discharge their water in huge volumes, it's more like a small steady flow- so the water volumes are not excessive for a 110mm stack. However if there are obstructions or constrictions (such as short radius bend) on the stack this could affect the ability of the pipe to cope with regular water discharges. Perhaps your 40mm waste is undersized for the job- especially where it is serving three appliances and if the pipe runs are laid flat with a lot of bends. Try this: fill your sink with water and run a simple fill and drain cycle on the machine/ washer. When the machine drains pull the plug in the sink, this will indicate whether your 40mm waste is adequate and capable of coping with the volumes of water involved. If it isn't get the builder to replace it with 50mm pipework, not a huge job but could be difficult to access now.

Thanks for the advice Carpenter, I will do that this evening.

By the way there are only 4 apartments in the building, two on the ground floor, two on the first floor, so I'm not exactly sure how the pipes are shared.

What I do know is that there are no apartments above me, and the other apartments have not experienced problems (so far), what might be important is that the apt directly below me hasn't yet got any appliances. So if the pipes weren't adequate this apt might experience problems when they have a w-machine/dishwasher and/or this might exacerbate my problem?

Based on what you're saying the existing 110mm stack should be more than adequate- I was thinking about a larger, multi storey installation, where you can have up to 6/ 8 apartments served by one soil stack. It's quite possible that the problem could be caused by debris in the pipework- tiling adhesive and grout are a big problem as they settle and solidify in pipework and traps etc. However I think you should carry out the test I suggested first off- eliminate the possibility of undersized pipework before pointing any fingers, so to speak.

Thanks I'll report back my findings

As a matter of interest, if you fill the sink bowl and allow to drain how long does this take? It should clear easily without too much gurgling.

To be honest I haven't really taken much notice, as I wouldn't have the sink filled very often. There is quite a bit of gurgling when the appliances are on though. By gurgling I presume you mean 'air noises'?

cian8 said:

There is quite a bit of gurgling when the appliances are on though. By gurgling I presume you mean 'air noises'?

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