mypros+
Error code reference

Thermador Range Error Code F70

Gaggenau Steam Oven ED-220/221

Thermador codesThermador range codes

Gaggenau Steam Oven ED-220/221: Water in base pan of oven, leaking from drain or internal hoses.

First step from the service manual

Correct leak, dry off the sensors on relay board.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for F70.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What F70 means on a Thermador range

The F70 error code on the Thermador/Gaggenau Steam Oven ED-220/221 indicates that water has accumulated in the base pan of the oven cavity. This is a water detection fault triggered when moisture reaches the sensors located on the relay board inside the unit. The oven's control system monitors the base pan for unexpected water presence, and when the sensors detect pooled liquid, the F70 code is generated to alert the user and halt operation before electrical components can be damaged.

The root cause of this fault is a leak originating from either the drain assembly or the internal water supply and steam hoses. These hoses carry water from the reservoir to the steam generation system and back out through the drain. Over time, hose connections can loosen, hose material can crack or degrade, and drain fittings can fail, all of which allow water to drip or flow into the base pan. Even a small, slow leak can accumulate enough water to trigger the sensors if left unaddressed.

Resolving this fault requires a two-step process. First, the technician must locate and correct the source of the leak, whether that means reseating a loose hose clamp, replacing a cracked hose, or repairing the drain connection. Second, once the leak is fixed, the base pan and the relay board sensors must be thoroughly dried before power is restored. Failing to dry the sensors completely can cause the F70 code to persist or reappear even after the leak has been repaired.

Source: manufacturer service documentation.

Common causes of F70

  1. 01

    Loose or disconnected internal hose

    Wiring / connection

    The hoses connecting the water reservoir, steam generator, and drain can loosen at their fittings over time. Inspect all hose connections for signs of weeping water or mineral deposits indicating a slow drip.

  2. 02

    Cracked or degraded internal hose

    Part replacement

    Heat cycling and age can cause internal water supply or return hoses to crack or become brittle. Look for visible cracking, pinhole damage, or soft spots along the full length of each hose.

  3. 03

    Drain assembly leak

    Part replacement

    The drain fitting or drain hose at the base of the oven cavity can fail at its seal or connection point, allowing water to bypass the drain path and pool in the base pan. Check the drain connection for cracks or failed gaskets.

  4. 04

    Wet or contaminated relay board sensors

    Wiring / connection

    Even after the original leak is repaired, moisture remaining on the relay board sensors can keep triggering the F70 fault. The sensors must be fully dried before power is restored to clear the condition.

  5. 05

    Overfilling or improper use of water reservoir

    Wiring / connection

    Overfilling the water tank beyond its rated capacity can cause water to enter areas not designed to handle it, leading to spillage into the base pan. Confirm the reservoir is filled only to the indicated maximum fill line.

See the test procedure for each cause

Frequently asked questions about F70

What does F70 mean on a Thermador range?
The F70 code on a Thermador/Gaggenau Steam Oven ED-220/221 means water has been detected in the base pan of the oven. This is caused by a leak from the drain assembly or one of the internal water hoses. The oven shuts down automatically to protect the electrical components from water damage. The leak must be located and corrected, and the relay board sensors must be dried before the unit will operate normally again.
Can I fix the F70 error myself, or do I need a technician?
Diagnosing an F70 fault requires accessing the internal hoses and relay board, which involves disassembling portions of the oven. A knowledgeable DIYer comfortable with appliance repair may be able to inspect hose connections and reseat loose fittings. However, if a hose or drain component needs replacement, or if the leak source is not immediately obvious, a qualified appliance technician is recommended to avoid further water damage or electrical hazards.
Is it safe to use my steam oven when the F70 code is showing?
No. The F70 code indicates standing water near electrical components inside the appliance. Operating the oven under these conditions creates a risk of electrical damage to the relay board and other internal parts, and poses a potential shock or short-circuit hazard. The oven should remain off until the leak is repaired and the unit is fully dried out.
Will resetting the oven clear the F70 error code?
A simple reset will not permanently clear the F70 fault if the underlying leak has not been fixed. Even if the code clears momentarily after a power cycle, the water detection sensors on the relay board will retrigger the fault if moisture remains or if the leak continues. The error will only stay resolved after the leak source is corrected and the sensors are fully dried.
How much does it cost to repair an F70 error on a steam oven?
Repair costs vary depending on the source of the leak. If the fix is as simple as reseating a loose hose clamp, the cost may be limited to a service call fee, typically in the range of $80 to $150. If a hose, drain fitting, or other component needs replacement, total costs including parts and labor can range from $150 to $400 or more depending on the specific part and your location.

Related Thermador range codes

All Thermador range codes
View all 180 Thermador range codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass