Blocked drains

Before calling a plumber, read on to see if there is a simple fix.

If you notice a sewer smell in or around the house, your toilet fills to near the rim and you hear gurgling in the bathroom or kitchen, particularly when someone is showering or flushing elsewhere, you probably have a blocked sewer. You will need a plumber to attend to the problem.

If, however, a toilet is blocked and everything else seems to be fine, you probably still have a blocked sewer line but it’s possible someone just used too much toilet paper. You can try a plunger and with any luck, the blockage will clear. Paper blockages are usually easy to clear and you can buy plungers more suited to toilets from any leading hardware or plumbing supplier. Toilet suites these days are designed to flush with much less water than in the past but this can result in more frequent paper blockages.

If you notice a sewer smell and nothing seems to be blocked, check the water seal in every fixture in the house. 

Generally, every toilet, basin, sink, shower, bath, etc. must flow through a P or an S trap. The trap holds a water seal to prevent sewer gases from entering the house.

S-trap showing depleted water seal.

Toilets have a built-in trap and you can see the water seal. If there is a partial blockage in the sewer line or the line was not vented properly when installed, this water seal can be sucked away when sewer flows through the line. If you notice the water level is lower than normal, this is the reason and would explain the smells.

The same can happen to every other trap in the house, so if this is occurring, you will need a plumber.

If you have a toilet or any other fixture that is not used for a long time, the water seal can evaporate and allow sewer gases into the house. When this occurs, simply flush the toilets and run a couple of litres of water through the showers and/or other fixtures. If the smell dissipates within an hour or so, your problem is solved.

Laundries are notorious for this because laundry floor waste traps cannot be charged by the laundry tub. The reasoning is that washing machine water will cause a lot of soap suds to flow out of the floor waste grate and inundate the room. So, unless the plumber installed a dry floor waste, which runs to the outside and doesn’t need to be trapped, you need to make sure water is poured into the floor waste when cleaning. Otherwise, the seal will evaporate, and you will get the sewer gases in the house. 

To summarize, if you have a paper blockage in a toilet, you can probably clear it quite easily with a plunger. If you have sewer smells in the house and nothing seems to be blocked, check the water seals in every toilet and fixture in the house, especially the floor waste drain in the laundry and any rarely used toilets, showers, etc.

S-trap with a full water seal.

When all else fails, you will need to call a professional. 

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