BAXI Boiler Troubleshooting: Common Problems & Error Codes

BAXI boilers used to be great, so it's unlikely your relic will give you much problems but clearly it has. So, here we go...

First, check your BAXI warranty
Turn it off and on again 🙄
Baxi fault codes
BAXI buggered? What now?

Introducing a woefully boring rundown of common BAXI problems & fault/error codes - applicable to BAXI 100, 200, 300, 400 & 600 combi, BAXI Duo-tec and EcoBlue combi’s in 2024.

First, check your BAXI warranty

All new BAXI boilers come with at the very least, a 2-year warranty with warranties up to a 10-years available, when they're installed by a BAXI-accredited installer.

Nobody really buys BAXI anymore so chances are you don’t have the paperwork for a boiler that the previous (and now dead) owners of your house threw in on the cheap before Gas Safe was even a thing.

Fortunately, there’s a million great engineers who can charm BAXI’s like snakes and likely recover your boiler. 🐍

Worst case, get a quote for a new boiler fitted by top engineers near you.

Don't forget that you'll need to have kept up your annual services in order to keep your warranty valid - your boiler warranty paperwork will detail this.

The below-mentioned fault codes are large errors with the boiler unit itself which means that if you're still covered by your warranty and had the boiler serviced annually, you should be covered for all these faults.

If required, here's a snapshot of what we charge for a typical, straightforward combi swap:

Boiler Model	From Price
*Ideal LogicNo longer fitted by Heatable** 5 year warranty	£1,995	Get Quotes
Viessmann Vitodens 050-W 10 year warranty	£1,990	Get Quotes
Viessmann Vitodens 100-W 10 year warranty	£2,455	Get Quotes
*Viessmann Vitodens 111-WBy reque** 10 year warranty	£4,180	Get Quotes
Worcester-Bosch 4000 10 year warranty	£2,890	Get Quotes
Worcester-Bosch 8000 10 year warranty	£3,200	Get Quotes

Turn it off and on again 🙄

Occasionally your boiler will display fault codes in error or because it very briefly detected an issue that didn't materialise. When it does this, the fault code will remain until it no longer detects the problem.

Sometimes though, it will require a bit of a nudge to detect this and restarting the boiler can be the wake-up call it needs to realise that actually, everything is alright.

Most Baxi boilers have a simple reset button on the front panel - locate this and press and hold the button for 1 to 3 seconds or until it's clear that the boiler has rebooted itself.

Baxi fault codes

[Applicable to Baxi 100, 200, 300, 400 & 600 combi, Baxi Duo-tec and EcoBlue combi in 2024]

Fault code	Source of erro	Heating engineer required?	Approx cost
E09	Gas valve connection cable	No - Baxi recommend initial reset before calling engineer	N/A
E15	Gas valve fault	No - Baxi recommend initial reset before calling engineer	N/A
E20	Central heating NTC *Negative Temperature Coefficient fault	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£200-£300
E28	Flue fault	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£150-£300
E40	Central heating return fault	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£60-£100
E55	Calibration required	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£60-£100
E109	Pre-circulation fault	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£100-£200
E110	Safety thermostat operated	No - Baxi recommend initial reset before calling engineer	N/A
E117	Water pressure too high	No - manually alter pressure gauge first	£50-£100
E118	Water pressure too low	No - manually alter pressure gauge first	£50-£100
E125	Circulation fault (primary)	No - Baxi recommend initial reset before calling engineer	N/A
E128	Flame failure	No - Baxi recommend initial reset before calling engineer	N/A
E130	Flue NCS operated	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£50-£100
E133	Gas supply interrupted or flame ignite failure	No - Baxi recommend initial reset before calling engineer	N/A
E134	Gas valve open without gas - time elapsed	No - Baxi recommend initial reset before calling engineer	N/A
E135	Interruption of gas supply	No - Baxi recommend initial reset before calling engineer	N/A
E154	Flow/return sensor temperature test	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£50-£100
E160	Fan fault	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£150-£200
E270	Circulation fault (dry fire)	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£100-£150
E321	Hot water NTC fault	Yes - contact Baxi (if under warranty/Gas Safe engineer if not)	£200-300
E384	False flame	No - Baxi recommend initial reset before calling engineer	N/A

Beyond repair? If it's a taxi for Baxi, compare quotes for a new boiler.

Have issues with your combi boiler? Read our boiler problems and solutions for quick troubleshooting guidance.

Related boiler troubleshooting guides:

BAXI buggered? What now?

You may need a new boiler.

You may need it fast, and with affordable monthly payments.

You may even need it from a company with top end local engineers, with 10,000 Trust Pilot reviews to back them up. Plus a Which? Trusted Trader award for good measure.

You may need a new boiler quote from us, Heatable 😘