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Is sewage backflow covered by insurance in Germany?

In short

Yes, backflow (Rückstau) is covered by almost every natural hazard add-on (Elementarschadenversicherung), but only when heavy rain or flooding pushes water from the sewer into the house. Standard buildings or contents cover does not pay for it. Most policies require a working backflow valve; fitting one usually costs EUR 1,500 to 2,500.

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Is sewage backflow covered by insurance in Germany?

What it costs

What backflow protection costs, based on published trade prices. The premium for the add-on itself is covered on our cost page.

Example	Typical range
Simple backflow valve, parts only	about EUR 95 to 200
Installation by a specialist firm, labour only	about EUR 500 to 800
Retrofit including installation, typical case	about EUR 1,500 to 2,500
Pumped system with open pipe access, real example	around EUR 2,900 including installation
Difficult position, floor slab has to be opened	over EUR 7,000 in individual cases

Guide values as of September 2026 from published cost examples. Annual servicing by a specialist at about EUR 100 to 200 is a guide value from our quoting practice.

Worked example

Detached house with a converted basement

A thunderstorm overloads the sewer, and 20 centimetres of waste water stand in the hobby room and the laundry room.

Drying screed, renewing walls and floor	about EUR 15,000
Heating and electrics in the basement	about EUR 6,000
Washing machine, dryer, furniture	about EUR 4,000
Buildings deductible	EUR 500

With the add-on in buildings and contents insurance and a serviced valve, around EUR 24,500 is paid. Without the required valve, a large part may stay with you.

What backflow means in your policy

In a heavy storm the public sewer fills up. Waste water can no longer drain away and rises back up through the pipes of your house. It comes out of floor drains, basement toilets or sinks that sit lower than the street.

German policy wordings usually cover this only if rain or an overflowing river is the cause. Water that runs in through basement windows or light wells is not backflow but heavy rain or flooding, which sits in the same add-on.

Situation	Does the natural hazard add-on pay?
Sewer overflows in a thunderstorm, water comes up the floor drain	yes, if you meet the conditions
No backflow valve although the policy requires one	often reduced or refused
Valve was dirty and did not close	reduction possible, depending on fault
Blocked house pipe without rain	no, that is not a natural hazard
Water runs in down the basement stairs	yes, as heavy rain or flooding

The backflow valve is the key point

Many policies state that drains below street level must be protected against backflow and that the protection must work. If you do not comply, you breach a contractual duty, and the insurer may cut or refuse the payout depending on how serious the breach is.

Your local council usually requires the valve in its drainage bylaws (Entwässerungssatzung) as well. Without it, the sewer operator is normally not liable for the damage.

What is different if you come from abroad

In the UK sewer flooding is often part of standard home insurance. In Germany it is not: you need the natural hazard add-on, and it is optional. Many rental and purchase contracts do not mention it at all.

Ask your landlord or the seller whether the house has a backflow valve and when it was last serviced. The paperwork is usually in German, and the German wording counts in a claim.

When you can skip it

If all drains, toilets and showers are above street level, sewage has no way to push back in. A valve is then unnecessary, and backflow hardly matters for your policy.

That often applies to houses without a basement or with a dry basement. You may still want the natural hazard add-on because of heavy rain from outside.

Tenants and owners

Damage to the building, such as screed, walls and heating, falls under the owner's buildings insurance (Wohngebäudeversicherung). Your washing machine, furniture and storage in the basement are only paid by contents insurance with the natural hazard add-on.

The owner is responsible for the valve. As a tenant, tell the landlord in writing if it is clearly not maintained.

Step by step

Find every drain, toilet and shower in the basement that sits lower than the street.
Check whether a backflow valve is fitted there and when it was last serviced.
Read whether your natural hazard add-on mentions backflow and which conditions apply.
Have a missing valve fitted by a specialist and keep the invoice.
Plan a yearly service and keep proof.

Checklist

Natural hazard add-on on the buildings insurance
Natural hazard add-on on contents insurance too, if you keep valuables in the basement
Backflow valve on every drain below street level
Proof of service from the last twelve months
Valuables in the basement not stored directly on the floor

Common mistakes

Assuming backflow counts as ordinary burst pipe damage
Fitting a valve and never opening it again until it is stuck
Insuring the building and forgetting your belongings in the basement
Converting the basement without checking the condition in the policy

Questions and answers

Frequently asked

Does buildings insurance pay for backflow without the add-on?

As a rule, no. Backflow caused by rain or flooding is almost always covered only through the natural hazard add-on.

Do I need a backflow valve?

If you have drains below street level, usually yes: councils often require it in their bylaws, and many policies make it a condition.

How often does the valve need servicing?

At least once a year, more often for pumped systems. Keep the proof, it helps in a claim.

What if the valve did not close during the flood?

The insurer then checks whether you neglected maintenance. Depending on the degree of fault, it may reduce the payout.

I have no basement. Do I need backflow protection?

Usually not, if all drains are above street level. The add-on can still make sense against heavy rain from outside.

Will the city pay if the sewer is too small?

Rarely. The bylaws require your own protection, and in exceptional rain the sewer operator is usually not liable.

Sources

NAMMERT insurance broker

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Natural hazard cover in Germany (Elementarschadenversicherung)

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