Baxi fault codes
Baxi boiler fault codes: what they mean and what to do
Baxi boilers show an E code when they shut down to protect themselves. Here’s what the common ones mean, what you can safely check, and when to call a Gas Safe engineer.
Rather we called you? Send us the details and we’ll ring you back.
- 4.9 from 383 Google reviews
- 9.87/10 on Checkatrade
- Gas Safe reg. 560123
- 12-month warranty on major repairs
Baxi codes
Find your Baxi code
These cover the Baxi 400, 600 and 800 ranges, plus older Duo-tec and Platinum boilers. Exact meanings can vary slightly between models, so check your manual too.
E133 · Gas supply interrupted or ignition failure
What it means: The boiler tried to light and couldn’t, usually because gas isn’t getting through or the flame isn’t being detected.
What you can safely check: Check your hob works and your prepay meter has credit. In freezing weather, check the condensate pipe outside isn’t frozen. Then reset once.
When to call us: The code returns. Common causes are the gas valve, the ignition electrode or the circuit board.
E118 / E119 · Low water pressure
What it means: The pressure in the heating system is too low for the boiler to run.
What you can safely check: If the gauge reads under 1 bar, top it up to between 1 and 1.5 bar, as your manual shows.
When to call us: It keeps dropping. That means a leak, the pressure relief valve or the expansion vessel.
E117 · Water pressure too high
What it means: The pressure has climbed above the safe limit.
What you can safely check: If the gauge reads well over 2.5 bar, let a little water out by bleeding a radiator, as your manual shows.
When to call us: It climbs again. The filling loop may be letting water through or the expansion vessel may need recharging.
E110 · Overheat safety thermostat
What it means: The boiler got too hot and the safety thermostat has tripped.
What you can safely check: Check the pressure and that your radiator valves are open, then reset once.
When to call us: It trips again. Poor circulation from the pump or sludge in the system is the usual cause.
E125 · Circulation fault
What it means: Water isn’t moving through the boiler properly.
What you can safely check: Check the pressure, then reset once.
When to call us: It returns. The pump may be failing or there may be a blockage.
E160 · Fan fault
What it means: The fan isn’t running as it should.
What you can safely check: Nothing to check yourself.
When to call us: Straight away. The fan or its wiring needs testing.
E28 · Flue fault
What it means: The boiler has detected a problem with the flue that takes fumes outside.
What you can safely check: From outside, check the flue terminal isn’t blocked, without touching it.
When to call us: Straight away. Flue faults are a safety issue.
E20 · Heating temperature sensor fault
What it means: The sensor that reads the heating water temperature has failed or come loose.
What you can safely check: Nothing to check yourself.
When to call us: Straight away. It’s usually a simple sensor replacement.
Before you call
Four things you can safely check first
Check the pressure
Look at the gauge on the front of the boiler. With the heating off it should sit between 1 and 1.5 bar. Below 1 bar is the most common reason for a fault code, and your manual shows how to top it up.
Check your gas
Does the hob light? If not, the problem is the gas supply, not the boiler. On a prepayment meter, check you’ve still got credit.
Check the condensate pipe
In freezing weather the plastic pipe running outside can ice up and lock the boiler out. Pour warm (not boiling) water along it, then reset.
Reset it once
Reset the boiler the way your manual shows. If the same code comes back, stop resetting and call an engineer, because repeated resets can hide a real fault.
Safety first
Smell gas? Leave the boiler alone
If you can smell gas, or your carbon monoxide alarm goes off, don’t try to reset the boiler. Turn the gas off at the meter if you can, open the windows, don’t use light switches or anything that could spark, and get everyone outside.
Never take the boiler casing off yourself. Anything inside the boiler is, by law, a job for a Gas Safe registered engineer.
Gas emergency
Call the National Gas Emergency Service. It’s free and open 24 hours a day.
Once it’s safe, call us on 07970 828 755 and we’ll get your heating back on.
Questions
Baxi questions
How do I reset a Baxi boiler?
Press and hold the reset button on the front panel for one to three seconds, or until the boiler restarts. Check your manual for your model. Only reset once: if the code comes back, call us.
Why does my Baxi keep showing E133 in winter?
The most common winter cause is a frozen condensate pipe. If that’s clear and the gas is on, it’s usually the ignition electrode or the gas valve, which we can test and replace.
Do you repair all Baxi models?
Yes. We repair the Baxi 400, 600 and 800 ranges, plus older Duo-tec, Platinum and Main boilers across North and East London.
My Baxi boiler is still under warranty. Who should I call?
Call Baxi first, as a repair by anyone else can affect the manufacturer’s warranty. If it’s out of warranty, call us: we diagnose the fault, agree the price with you before any work starts, and back major repairs for 12 months.
Other boiler fault codes
Can’t clear the code? We repair every major make across North and East London. Boiler breakdown repair · Areas we cover
Call back
Baxi showing a fault code?
Tell us the code and your boiler’s make and we’ll get back to you. If you’ve got no heating or hot water, call us now on 07970 828 755, day or night.