Quick answer: Baxi E110 means the boiler’s water got too hot, or heated up too quickly, and the overheat safety thermostat shut it down. Poor circulation is usually to blame, such as a sticking pump, trapped air or low pressure. Let the boiler cool, check the pressure, bleed any cold radiators and reset once. If E110 returns, call a Gas Safe engineer.
E110 is Baxi’s overheat lockout. It tends to appear when the heating is working hardest, which makes it all the more frustrating. Sometimes it’s a quick pressure fix. Other times it’s a sign the pump or the system itself is wearing out. If your Baxi is over 8 years old, out of warranty and E110 keeps coming back, a new gas boiler installation in Edinburgh can be the more sensible long-term answer.
What does the Baxi E110 error code mean?
E110 means the overheat protection has operated. Baxi’s fault table gives two triggers. Either the boiler hit its maximum temperature too quickly, which Baxi says usually means a jammed pump or air in the circuit, or the safety thermostat has tripped. Some displays show just “110” with a reset symbol.
You’ll find E110 on Baxi Duo-tec, Platinum, Assure, EcoBlue and Megaflo boilers, as well as some Potterton and Main models. The newest Baxi Combi 2 boilers use a different code for overheating.
What causes a Baxi E110 overheat fault?
Poor circulation causes most E110 lockouts. When water can’t carry heat away, the boiler overheats.
| Cause | What’s happening | Can you check it? |
|---|---|---|
| Pump failed or seized | Water isn’t being pushed round the system | No, engineer |
| Air in the system | Air pockets block the flow | Yes, by bleeding radiators |
| Low pressure | Not enough water to take heat away | Yes, on the gauge |
| Sludge or blocked heat exchanger | Build-up restricts flow inside the boiler | No, engineer |
| Closed or stuck valves | A radiator, isolation or diverter valve isn’t opening | Partly, radiator valves |
| Faulty sensor or safety thermostat | The part itself has failed | No, engineer |
How do you fix a Baxi E110 error?
Let it cool, check pressure and air, then reset once.
- Switch the boiler off and give it at least 30 minutes to cool.
- Check the pressure gauge. Baxi recommends 1 to 2 bar. Top up via the filling loop if it’s below 1.
- Bleed any radiators that are cold at the top, then check the pressure again.
- Open any closed radiator valves.
- Turn the boiler back on and press the reset button briefly, about 1 second on most current Baxi models.
If E110 comes back, leave it off and book a boiler repair. Don’t keep resetting an overheat lockout. Each time it trips, the heat exchanger takes more strain.
Why does my Baxi keep showing E110?
A recurring E110 almost always means a circulation problem that hasn’t been fixed. Topping up and bleeding may get the boiler running for a while, but if the pump is weak or the system is full of sludge, the overheating will return. Our Baxi E125 guide covers circulation faults, which often come before E110.
Why do overheat faults cluster at the start of a Scottish winter?
A pump that’s barely been used all summer is suddenly asked to run for hours. In Scotland the heating often goes from off to on full in a matter of days once October arrives. A pump with worn bearings, or one that’s partly seized, can’t keep up. Pressure that has quietly dropped over the summer adds to the problem.
A quick autumn check of your pressure gauge, and bleeding radiators before you need them, can stop a lot of early-winter E110s.
How much does it cost to fix Baxi E110?
If pressure or air is the cause, nothing. If a part or the system needs attention, roughly the figures below.
| Repair | Typical UK cost |
|---|---|
| Pressure top-up and bleeding (DIY) | £0 |
| Thermostat, sensor or valve fix | £100 to £300 |
| Pump replacement | £150 to £400 |
| Power flush | £350 to £800 |
| Heat exchanger replacement | £400 to £940 |
Indicative prices from published UK trade guides, 2024 to 2026. Your quote depends on the model, parts and size of your system.
Should you repair or replace a Baxi with E110?
Repair it if the boiler is under 8 years old or in warranty. If it’s older, out of warranty and needs a pump, a power flush or a heat exchanger, get a replacement quote first.
Overheating wears a boiler out faster, and once one major part goes on an older model, others tend to follow. A new A-rated boiler fitted onto a cleaned system comes with a fresh manufacturer warranty, often 7 to 10 years, and uses less gas to heat your home. Get a free new boiler quote and weigh it against the repair.
Does regular servicing prevent E110?
Yes. A yearly boiler service includes checking the pump, cleaning the magnetic filter and testing the system’s inhibitor level. Those are the three things that most often lie behind an overheat lockout.
When should you call an engineer for Baxi E110?
Call a Gas Safe engineer if E110 returns after the boiler has cooled and you’ve checked the pressure and bled the radiators. Call sooner if you hear banging or gurgling from the boiler.
Baxi Boiler Repairs Across Edinburgh and Scotland
The Edinburgh Boiler Company repairs, services and replaces Baxi, Potterton and Main boilers across Edinburgh and the surrounding areas. We carry out boiler repairs in Mayfield and Bathgate, and install new boilers across Scotland, from Galashiels in the Borders to Paisley in the west. If your Baxi keeps overheating, our Gas Safe engineers can help.
Frequently Asked Questions About the Baxi E110 Error
Does E110 mean the pump has failed?
Often, but not always. Baxi’s own description names a jammed pump or air in the circuit as the likely cause. Check pressure and bleed the radiators first. If E110 still returns, an engineer should test the pump.
Can low pressure cause Baxi E110?
Yes. With too little water, heat can’t be carried away fast enough. See our Baxi E119 guide for more on pressure faults.
Is it safe to use my boiler with E110 showing?
The boiler won’t run while E110 is showing, which is what keeps it safe. The risk comes from resetting it over and over without fixing the cause.
Is E110 the same on Potterton and Main boilers?
Yes, on models that share Baxi’s controls it means the same overheat lockout. For other codes, see our Baxi boiler error codes guide.
