Signs you need internal drain unblocking help
- One or more fittings draining slowly
- Gurgling from sinks when the toilet flushes
- Water backing up into the washing machine drum
- A bad smell from waste pipes indoors
Internal Drain Unblocking: what the job involves
Internal drains are the waste pipes inside your home. Specifically, they carry water from sinks, baths, showers, washing machines and toilets to the soil stack. From there, the waste drops to the drain outside. A blockage anywhere along that route can slow one fitting or several at once.
The engineer starts by checking which fittings are slow. For example, if only the bathroom basin is slow, the problem is probably in its trap or waste pipe. If the toilet and bath are both slow, the blockage may sit in the soil stack or the drain below. That tells them where to start work.
They clear the blockage with a drain snake, rods or a small jetter. Where a pipe has a rodding eye, they use it, since that avoids taking pipes apart. Afterwards, they run water through each fitting to check the flow. They also point out any fittings with poor fall that may block again.
How the job goes
- 1. Trace the slow fittings The engineer checks which fittings are slow to find where the pipes join.
- 2. Clear the pipe They clear the blockage through the trap, a rodding eye or the soil stack.
- 3. Test each fitting They run water through every fitting to check the flow.
Typical costs
UK price guides put sink, bath and toilet unblocking at about £30 to £75 outside London (Fantastic Services, 2026). A blocked soil stack or a job that needs jetting costs more. Other guides put drain unblocking in general at about £80 to £250. These are typical ranges, and you can ask your engineer to confirm the price before they start.
Around Wolverhampton
Older homes around Wolverhampton often have cast iron or early plastic soil stacks. While these last a long time, joints and bends inside can catch waste. Homes that have added a downstairs toilet or utility room may also have long waste pipes with little fall. If your home has had changes like these, mention them in your request.
Internal Drain Unblocking: frequently asked questions
Why are all my fittings draining slowly?
When every fitting is slow, the blockage usually sits in the soil stack or the drain outside, because that is where all the pipes meet. The engineer checks the outside manhole first in that case.
Why does my sink gurgle when I flush the toilet?
Gurgling means passing water pulls air through the trap. A partial blockage can cause it, while a problem with the pipe venting can too. The engineer checks both.
Can a washing machine block a drain?
Yes, lint and soap can build up in the waste pipe over time. As a result, water may back up into the drum or the sink next to it. Clearing the waste pipe usually solves it.
Will you need to take pipes apart?
Sometimes, although the engineer tries to use traps and rodding eyes first. If they need to open a pipe, they tell you before starting. They then refit it and test for leaks.