Baxi E133 Error Code: What On Earth It Means (Plus, How To Fix)

If your BAXI boiler is flashing E133, your home has officially entered survival mode, full blown Bear Baxi Grylls style. No heating, no hot water, just the freezing cold embrace of despair.

But, before you start setting belongings, or mother-in-laws on fire in an attempt to keep warm, let’s break down what this error actually means and, more importantly, how to fix it (hopefully).

What Does the BAXI E133 Error Code Mean?

The E133 error is your BAXI boiler’s way of passive-aggressively informing you that it’s not getting enough gas to function. No gas means no ignition, and no ignition means your boiler is about as much use a chocolate teapot.

To summarise, here’s what could be causing the issue:

• Gas supply issues
  If your gas meter is empty or your supplier has cut you off (bit rude), your boiler will refuse to work.
  

• Frozen condensate pipe
  Because winter enjoys ruining lives (unless you’re making snowmen), this external pipe can freeze and block water from escaping, shutting down your boiler as a precaution before it blows. Believe it or not, we’ve written a super boring guide on condensate pipes.
  

• Low gas pressure
  If your gas supply is weak, your boiler won’t have the power it needs to fire up properly.
  

• Blocked flue or ventilation issue
  Your boiler needs fresh air to function. If the flue is clogged, it will shut down before things get dangerous.

If the error code has just appeared, don’t panic (yet), there are a few things you can try before calling an engineer.

How to Fix the Baxi E133 Error

Assuming it is fixable, that is. Let’s give it a curly whirly:

1. First, Check Your Gas Supply

The first (and most insanely obvious, borderline offensive) thing to do is confirm whether you actually have a gas supply, feeding your BAXI.

If it doesn’t, your boiler might not be the issue at all, it’ll actually be your own doing (or your cash greedy pig of a supplier)

Here’s how to check if your BAXI’s got gas:

• Try turning on your gas hob (if you’ve got one). If it’s not lighting, your home isn’t getting gas

• If you have a prepaid (pay as you go) meter, make sure you haven’t run out of credit (it happens to the best of us, at the worst of times)

• If you suspect a supply issue, call your gas provider to check for outages in your area

If your gas supply is fine, gutted. Let’s move on to the next step.

….drum roll please… 🥁

2. Reset Your Boiler

The classic “turn it off and on again” actually works, believe it or not. Sometimes, your boiler just needs a fresh start to clear the error code.

Here’s a massive guide on how to reset your boiler, or, here’s a short one:

1. Locate the reset button on your BAXI boiler’s control panel.

2. Press and hold it for 5 seconds.

3. Wait for the boiler to reboot and see if the error clears.

If the error returns, it’s time to get your hands a little colder.

3. Check for a Frozen Condensate Pipe

If it’s colder than your ex’s heart outside, your condensate pipe could be frozen.

This little pipe runs from your boiler to the outside, and if it gets blocked with ice, your boiler will shut down faster than a fat thing that’s sat down too fast.

Here’s a quick guide on how to defrost your condensate:

• Find the white plastic pipe leading from your boiler to outside.

• If it feels solid or looks frosty, it’s probably frozen.

• Pour warm (not boiling) water over it until the ice melts.

• Reset your boiler and check if it’s back in action.

For more in-depth guidance on this problem, check out our boiler losing pressure guide, as frozen pipes and pressure loss often go hand in hand.

4. Inspect the Flue and Ventilation

Probably the most unlikely cause of an E133 error, but, let’s try anyway for the lolz.

In order to actually work, your BAXI boiler needs proper airflow. If the flue is blocked, your boiler will refuse to light as a safety precaution, thus throwing our favourite error.

It’s bloody easy to check:

• Head outside and inspect the flue (the big pipe sticking out of your wall)

• Look for debris, snow, or even an enthusiastic bird that’s built a nest in it

• If the flue is blocked, clear the obstruction and try to reset your boiler

If your boiler still won’t fire up, it’s time to consider whether your gas pressure is the culprit.

5. Check for Low Gas Pressure

Low gas pressure can stop your boiler from igniting properly, leading to the E133 error. This could be down to a supply issue or a fault inside the boiler itself (gutted if it is).

• If your neighbours are also experiencing problems, your gas supplier might be having an issue—give them a call.

• If the issue is isolated to your boiler, an engineer will need to inspect for internal faults. Don’t you dare touch it, you maniac.

If you suspect your boiler is struggling with pressure issues in general, our guide on boiler pressure too high or boiler pressure too low can help you diagnose other common problems.

E133 Troubleshooting Table

When to Call an Engineer

If you’ve tried all of the above and your boiler is still giving you the silent treatment, it’s time to call a Gas Safe registered engineer. They’ll be able to:

• Test your gas pressure to see if it’s a supply issue.

• Inspect the ignition system and repair any faults.

• Investigate any internal blockages or faulty sensors.

If your boiler is over 10 years old and constantly breaking down, it might be more cost-effective to replace it entirely. Before you commit to yet another repair bill, take a look at our guide on new boiler costs to see if upgrading makes more sense.