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Seeing the Vaillant F62 error code on your Vaillant ecoTEC boilers means that there’s an issue with the gas valve. As a result, your Vaillant boiler will lock out for safety reasons. This is how Vaillant defines the fault:
| Vaillant boiler error Code | Meaning |
| F62 | Faulty gas valve |
Never attempt to fix the Vaillant ecoTEC F62 error code yourself – always hire a Gas Safe registered engineer.
What is a boiler gas valve?
When the temperature on the thermostat is increased, and the central heating needs to fire into action, a gas boiler will need a supply of gas and that’s where the gas valve comes in. The gas valve opens up as and when the boiler needs more fuel to burn the flame that will heat the hot water before it circulates around the central heating system.
When a gas boiler doesn’t need a supply of gas (the central heating isn’t on), the gas valve should remain closed. Otherwise, gas will continue to make its way into the boiler and your home, which can be very dangerous.
A Vaillant boiler is able to detect when gas is passing through the gas valve at times when it shouldn’t be doing so. For safety reasons, your Vaillant boiler will lockout and display the F62 error code. It could be that the gas valve is remaining wide open, partially open, or opening at the wrong times.
How dangerous is a faulty gas valve?
A gas leak is dangerous in any circumstance. When your Vaillant boiler detects gas escaping through the gas valve it will show the F62 error code and lockout. This means the boiler will shut off and cease to work until the issue has been resolved by a trained professional.
If you smell gas, turn off the gas supply and your boiler and contact a heating engineer right away.
Fixing the Vaillant ecoTEC F62 Fault
Before being able to fix the fault, a heating engineer will first need to find the cause, because there are several possible reasons why you’re seeing the F62 error:
- The gas valve is stuck;
- Signals from the printed circuit board (PCB), which is the part that tells the gas valve when to open, are being sent at the wrong times;
- Connection between the gas valve and the PCB is intermittent.
When the Gas Safe registered engineer arrives to fix the fault, they will have to start by determining whether the issue lies with the gas valve or the electronics.
Depending on the issue, there are a few possible fixes:
- Repair the gas valve
- Replace the gas valve
- Repair the electronics
By law, only a Gas Safe registered engineer should repair or replace the gas valve in a gas boiler so don’t attempt to fix it yourself. Always hire a fully-qualified professional.
How much does a gas valve cost?
Should the gas valve be beyond repair, it will need replacing which could end up costing around $300 for a Vaillant boiler. Should the issue lie with the electronics, rather than the gas valve, the PCB might need to be replaced and this is often more expensive than a gas valve replacement, with the part alone costing $300 – $550.
If your Vaillant boiler was installed more than 8 years ago, you might want to consider a replacement boiler rather than replacing a part for the unit to need replacing within a few years anyway.
