How to Reset a Baxi Boiler (and When Not To)

Before you press reset

A reset clears a lockout. It does not fix whatever caused it. So spend a minute on the cause first, or the boiler will simply lock out again.

• Write down the code on the display, and note whether an R or a spanner symbol is showing.
• Check the pressure gauge. Baxi recommends about 1.5 bar and says to top up if it falls below 1 bar. Our Baxi boiler pressure guide shows how to use the filling loop.
• Light a gas hob or fire to prove gas is reaching the house. On a prepayment meter, check the credit.
• In freezing weather, check the white plastic condensate pipe outside. If it is iced up, thaw it with warm water, not boiling.

Never reset a boiler if you can smell gas. Open windows, turn off the gas at the meter if you safely can, leave switches alone, then get out and call the National Gas Emergency Service on 0800 111 999.

How to reset each type of Baxi control

Baxi has used three kinds of control over the years. Look at the front panel and match yours.

• Reset button, as on the Baxi 600, 800, EcoBlue Advance and Duo-tec 2 GA: press and hold the button marked R, or with the reset symbol, for about five seconds, then release. The code should clear and the boiler shows its temperature again.
• Selector switch with an R position, as on older Platinum boilers: turn the ON/OFF/Reset switch to R, hold it there for at least five seconds, then release.
• Temperature dial with a red lockout light, on some older boilers: turn the dial to its reset mark, usually at the fully anticlockwise end, hold it for a few seconds until the red light goes out, then turn it back to your usual setting.

Why the Baxi reset button is not working

When pressing reset does nothing, or the code comes straight back, it is almost always one of the following.

• A spanner symbol is showing. On Baxi displays this marks a fault the user cannot reset, however long you hold the button. Only an engineer can clear it.
• The pressure is still too low. A low-pressure code is not cleared by the reset button; it clears when the pressure rises. On the Baxi 800, EcoBlue Advance and Duo-tec 2 GA it shows as 118, on older Platinum and later Duo-tec boilers as E119, and on the newer 600 Combi 2 as A.02.06 or H.02.07.
• The press was the wrong length. Baxi’s current guides say hold for five seconds, but the original Baxi 800 manual says press for about one second and warns that holding longer than two seconds stops it resetting. If five seconds does nothing, try one short press.
• The cause is still there. A frozen condensate pipe, no gas, or a failed part will lock the boiler out again as soon as it tries to light.
• There is no power. A blank display means check the fused spur and the fuse board, not the reset button.

How many times should you reset it?

Once, as a test. Twice if you have fixed something in between, such as thawing the condensate pipe. Baxi’s own advice is that frequent lockouts mean a fault is present and you should call your installer or a service engineer.

Resetting over and over does not wear the fault away. It hides a pattern an engineer needs to see, and a boiler that locks out every few hours is on the way to one that will not run at all. If the same code comes back, stop and get it looked at, especially in winter.

A reset that clears the code but leaves you with cold radiators is a different problem. If the radiator symbol then flashes for a long time, read our guide to a Baxi radiator symbol flashing.

When you should not reset at all

Some situations call for switching the boiler off, not resetting it. Turn it off at the fused spur and leave it off if water is dripping from under the casing (check the spur is dry first), if you hear loud bangs or roaring as it tries to light, if the pressure gauge is close to 3 bar and the pipe outside is discharging, or if you see soot or scorch marks around the case or flue.

The same goes for anyone feeling headaches, dizziness or nausea that ease when they leave the house. Those can be signs of carbon monoxide. Open windows, switch the boiler off, get everyone outside, call 0800 111 999 and seek medical advice before anyone touches the boiler again.

Common Baxi codes and whether a reset helps

The Baxi 800 combi user guide lists these, and the EcoBlue Advance and Duo-tec 2 GA use the same numbers; later Duo-tec models add an E in front (E119, E133). A flame or gas failure, 133, is the classic resettable lockout: check the gas and condensate pipe, then reset once. A pressure fault, 118, needs topping up rather than a reset. A circulation fault, 125, a fan fault, 160, and sensor faults point to parts that have failed, and a reset rarely lasts. On older two-digit displays, E1 followed by two digits is one longer code split in two, so read both halves before you decide.

Our Baxi flashing red light guide covers the older boilers that show a lockout with a light instead of a number.

What an engineer does when a reset will not hold

An engineer reads the fault history, then tests the gas pressure at the boiler while it tries to light, checks and cleans the condensate trap, inspects the ignition and flame-sensing electrode, and checks the fan, pump and pressure sensor depending on the code. Most lockouts that keep returning come down to one worn part.

As typical market prices including fitting, an electrode is roughly £80 to £160, a fan £200 to £350 and a main board £350 to £700. A blocked condensate trap is usually a quick clean.

For Baxi boiler repair the call-out is £60 at any hour, and the repair price is agreed with you on site before any work starts. Gas work is carried out by Gas Safe registered engineers.