# Why are all the drains in my house slow?

When every drain in the house is slow at the same time, the problem is downstream of the fixtures. On a septic property that usually means a full tank, a clog in the main line to the tank, a failed outlet baffle, or a drain field that cannot accept flow. A single slow sink is a fixture clog. Whole house slowness is a system problem. Stop heavy water use and have the tank level checked before it turns into a backup.

## Key takeaways

- When every drain in the house is slow at the same time, the problem is downstream of the fixtures.
- Most common cause: Tank is full and overdue for pumping. Sludge and scum reach the outlet, liquid backs toward the house, and every fixture slows together.
- Do this first: Stop laundry and dishwasher use immediately.
- Treat it as an emergency if water is rising in a floor drain or shower pan

## What you are seeing

- Tubs, sinks, and toilets all drain slowly
- Gurgling in a tub when a toilet flushes
- Toilets that need a second flush
- Drains get worse after laundry day

## What it usually means

- **Tank is full and overdue for pumping** (Most likely). Sludge and scum reach the outlet, liquid backs toward the house, and every fixture slows together.
- **Main line clog between house and tank** (Common). Wipes, grease, or a belly in the line restrict flow. Nothing past that point drains right.
- **Drain field failure** (Common). If the field will not take effluent, the tank stays full and the house drains slowly no matter how often you pump.
- **Collapsed or root filled line** (Possible). Older clay or cast lines crack and roots move in, especially on mature Front Range lots.
- **Blocked plumbing vent** (Less common). Without air, drains glug and slow even when the tank is fine.

## What to do right now

1. Stop laundry and dishwasher use immediately.
2. Avoid chemical drain cleaners. They damage the bacteria in the tank.
3. Check when the tank was last pumped.
4. Watch for gurgling, which points to venting or a partial main line clog.
5. Call 720-427-7557 for a pump and inspection.

## When it is an emergency

- Water is rising in a floor drain or shower pan
- Sewage odor is inside the house
- The lowest fixture in the house has already backed up

## How we fix it

1. **Pump and measure.** We pump the tank first. If drains clear instantly, the tank was the cause. If not, the line or the field is.
2. **Clear the main line.** We cable or jet the line between the house and the tank and confirm full flow.
3. **Read the field.** Fast liquid return after pumping means the field is the real problem and needs a repair plan.

## What affects the cost

- Tank size and how overdue the pump-out is
- Whether line cleaning or camera work is required
- Depth and access to the cleanout or tank lid
- Any repair found at the baffle or outlet

## Related services

- [Septic tank pumping in Denver](https://www.affordablesepticpumping.com/septic-tank-pumping-denver): Scheduled and same-day pump-outs across the Front Range.
- [Septic locating and troubleshooting](https://www.affordablesepticpumping.com/septic-system-locating-and-trouble-shooting): We find the tank and the fault when nobody knows where either one is.
- [Septic system repair](https://www.affordablesepticpumping.com/septic-system-repair-denver): Line, baffle, lid, pump, and drain field repairs.

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Source page: https://www.affordablesepticpumping.com/slow-drains-whole-house
Affordable Septic Pumping, 8996 Pierce St, Westminster, CO 80021. Phone 720-427-7557.