How To Reset a Vaillant Boiler

Most modern boilers, including those in Vaillant’s range, have safety mechanisms that trigger lockout mode when an issue is detected. Once you’ve identified the meaning behind the error message, the next step is to reset the boiler.

Remember that reset procedures vary by brand, and even within the Vaillant range, different models may have slightly different methods.

Several error codes can indicate a system shutdown or lockout mode in Vaillant boilers. The underlying issue must be addressed before the boiler can be reset.

These include:

• F28 — Ignition failure (no gas or failure to ignite)
• F29 — Flame failure after ignition (burner shuts off during operation)
• F24 — Dry fire or insufficient water in the system
• F22 — Low water pressure (can cause overheating and shutdown)
• F20 — General overheating (water temperature too high)
• F75 — Faulty pump or pressure sensor (no pressure detected during startup)
• F61 / F62 — Gas valve faults (mechanical or electrical issues)
• F63 / F64 / F65 — Control unit errors (internal electronics fault)
• F67 — Faulty flame detection system
• F32 — Fan failure or fan speed fault
• F36 — Flue gas sensor trip (flue temperature too high)
• F83 — Flow/return temperature sensor mismatch (suggests a circulation issue)

Error codes can vary depending on the model and year of your Vaillant boiler, so it’s always a good idea to consult your user manual for specific meanings.

Resetting your Vaillant boiler is typically done to restart the system and bring it out of lockout mode.

While the reset process is generally straightforward, following a few basic steps can ensure it’s done correctly and safely.

Performing A Reset Of A Vaillant Boiler

There are three main reset procedures for Vaillant boilers. These include:

Reset Button Method

Found on older models like:

• Vaillant ecoTEC Plus (early versions)
• Vaillant TURBOmax

To reset these older models, press and hold the dedicated reset button (often marked with a flame symbol or a circular arrow) for 3–5 seconds until the boiler restarts.

Control Knob/Dial Method

Standard on many ecoTEC models:

• ecoTEC Plus
• ecoTEC Pro
• ecoFIT Pure

To reset these boilers, turn the mode selector dial (usually with symbols for heating and hot water) to the reset position (a circular arrow), hold it briefly, and then return it to its original setting.

Digital Display with Touch/Soft Buttons

Used on newer models like:

• ecoTEC Exclusive
• ecoTEC Plus (recent models with LCD displays)

To reset these newer boilers, you’ll need to use the touch-sensitive controls or menu buttons to navigate to the “Reset” function on the screen and select it.

While each reset procedure will differ slightly, the general steps are ultimately the same.

Step One: Error Code

Before you reset your Vaillant boiler, make sure to note the error code. Snapping a quick photo or jotting it in your manual works just fine.

It won’t affect the reset, but it’s handy if the problem comes back or you need to call a Gas Safe engineer for help.

Step Two: Reset Boiler

Depending on the model, there are several different ways to reset your Vaillant boiler, and thankfully, most are quick and easy.

For the reset button method, press and hold the dedicated reset button (often marked with a flame symbol or a circular arrow) for about 3–5 seconds until the boiler begins to restart.

When resetting a Vaillent boiler with a dial, turn the mode selector dial to the reset position (look for a circular arrow icon), hold it briefly, and then turn it back to your desired setting.

The last method is to use the touchscreen or menu buttons to navigate to the reset option on the display and select it.

If everything has gone perfectly, reigniting the boiler will take a minute or two.

After the boiler has returned to its usual state, check that the hot water and heating systems are working correctly.

However, if this has not removed the error code and it has reappeared, you can consider doing a manual reset.

Step Three: Turn Off The Power

Although this step is not in the manual, sometimes you may need to reset your Vaillant boiler by turning it off at the power source.

Look for a fused spur switch near the boiler. It’s usually a small white box with a large switch in the centre. Flip the switch off, wait a few seconds for the boiler to shut down fully, and then turn it back on.

In some setups, the boiler might be simply plugged into a standard wall socket. If that’s the case, you can switch it off and on at the plug.

If you can’t find a nearby switch or plug, your last option is to reset it at the main distribution board, also known as the:

• Panelboard
• Circuit breaker panel
• Breaker panel
• Electrical panel
• Fuse box
• Or DB board/box

Once the power is restored, your Vaillant boiler should reboot and complete the reset process.

But if you still get the same error message, you will want to do some more troubleshooting.

Further Troubleshooting If Your Boiler Fails To Reset

As with everything in life, the simplest tasks can become more complicated. If you’ve reset your Vaillant boiler and you’re still getting error codes, you will want to perform a few quick checks:

Identify The Error Code

You only want to reset your Vaillant boiler if it is in lockout mode. Make sure to double-check what the error code means.

Usually, the manufacturer will include a comprehensive list of error codes in their manual.

If you’ve lost your manual or are struggling to find a solid answer, you can do some simple checks before calling in a professional.

Check The Gas Supply

A simple check is to see if your home’s main gas supply valve is fully open. Your home’s gas mains should be fully open.

Turning on other gas appliances, such as a kitchen stove, is another way to check for a gas supply issue in your home.

If you suspect a gas supply issue, contact your gas provider. There might be a local supply issue in your area.

However, if you smell gas, turn off the supply immediately and call for help.

Check Water Pressure

Most Vaillant boilers have a pressure gauge on the front panel as a dial or analog gauge, a digital screen, or, on older models, a physical gauge under the unit.

The Vaillant reading is between 1.0 and 1.5 bar when the system is cold.

If the water pressure reading is below 1.0 bar, your boiler might need to be repressurised.

On the other side of the scale, if your Vaillant boiler’s reading is too high, above 2.5 bar, you will want to bleed a radiator in your home to lower the pressure.

Check The Power Supply

It could be an electrical issue if your boiler has not turned back on after the reset.

Ensure the boiler is plugged into a working power socket and no circuit breakers have tripped.

For those who turned off their boiler via the fuse spur switch, a fuse could have blown if flipping the switch had not resulted in power feeding to the boiler.

While most of these checks can be completed relatively quickly, if you’re struggling to reset your boiler, we highly recommend calling an expert for help.

Call WarmZilla’s Professionals For A Chat

Rather than struggling to reset your Vaillant boiler, you can call one of our professionals to troubleshoot the problem.

However, if you both discover a more substantial issue, the professional on the phone will suggest sending a Gas Safe registered engineer to your home within 48 hours to reset your boiler.