Why is it that mainline sewer backups always seem to occur (1) after hours for the plumber, or (2) when you have a house full of people? Seriously. Why is that?
Usually we chalk that kind of thing up to Murphy's Law - "Anything that can go wrong, will go wrong." But truthfully, there are often signs of impending problems. Heed the signs and you just might be able to respond before the line becomes completely clogged and waste water backs up into the building.
Here are a few things to pay attention to:
1. Are Multiple Fixtures Affected?
A very obvious sign of a sewer drain clog is when more than one plumbing fixture is draining slowly or backing up at the same time. If you suspect that you have a sewer drain clog, check other fixtures in the home - particularly the tub and shower.
Toilets have the most direct path to the sewer and the biggest drain line in the house, so if there is a problem with the sewer line you shoiuld notice it when you try to flush the toilet. It's rare to have a mainline sewer stoppage when the toilets are working properly.
And then tub and shower drains sit lower than sink drains, so check them next. Do you have water backing up or failing to drain in your tub/shower? If so, it's probably time to call the plumber.
2. Out-of-the-Ordinary Occurences (with respect to plumbing fixtures).
Don't ignore burbling sounds or waste water moving upstream.
If you've got an issue with the sewer line, air may get trapped in the plumbing system. Do you get bubbles in the toilet bowl when you run the faucet in the closest sink? Do you get ominous gurgling sounds when you flush the toilet or take a shower? These are all signs that waste water isn't moving smoothly through the system.
And definitely if you have water rising one place when you're using a fixture another place, you've got issues somewhere in the sewer line. For instance, if the water draining out of the washing machine causes the toilet to overflow or backs up into the tub or shower it could mean a clog on the main sewer line. (Although if the toilets are still flushing fine while this occurs then this is likely due to a washing machine stoppage and not a mainline stoppage.)
3. Check the Drainage at the Clean-Out
If you have a mainline clean-out (and hopefully you do), you can remove the cap and physically check to see whether or not the line is draining. You should not be able to see the water coming up the clean out pipe. If water is flowing up and out of the clean out or standing in the pipe, the line is not draining.
4. And Lastly...
If your house has a septic system, always ask yourself: "How long has it been since the tank was cleaned out?"
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The problem could be a straight forward clog or there could be roots or some other kind of break in the line that prevents the line from clearing completely. These issues don't necessarily happen all of a sudden but develop over a period of time. Watch for indications that something is not right on the drain lines.







