Baxi E119 fault code — what it means and how to fix it

What does the Baxi E119 fault code mean?

The Baxi E119 fault code means low system water pressure — the boiler has detected pressure below 0.5 bar and locked out to protect itself. You can usually fix it yourself in minutes: top the pressure back up to 1.0-1.5 bar using the filling loop under the boiler. If the pressure keeps dropping, there's likely a leak.

E119 shows up across the Baxi combi range — the 600, 800, Platinum and Duo-tec models all use it. It's purely a pressure fault, so it's easy to mix up with other Baxi codes: E133 is a gas supply or ignition fault, and E110 is an overheat. E119 is different — nothing is wrong with the gas side, there simply isn't enough water in the sealed heating circuit for the boiler to run safely.

Low pressure is one of the most common reasons a Baxi shuts down, and topping it up is a genuine homeowner job. The one thing worth understanding before you touch anything: if the pressure falls again soon after you top it up, the boiler isn't the problem — something in the system is losing water, and that needs looking at.

Key facts

The quick version, before we get into the detail.

• What it means: low system water pressure lockout (below 0.5 bar).
• DIY-fixable: yes — repressurise to 1.0-1.5 bar via the filling loop, usually under ten minutes.
• Gas Safe job if: the pressure keeps dropping (a leak, a passing pressure relief valve, or a failed expansion vessel).
• Typical UK boiler repair: around £300, with a usual range of £120-£750 (Checkatrade, 2026).
• Smart Plan boiler cover: parts and labour up to £500 if the boiler is under 7 years old, or up to £200 if it's over 7 years — and it's for future breakdowns, not a fault your boiler is already showing.
• Call-outs are booked Mon-Fri 08:00-18:00 (outside those hours only for an emergency breakdown); a £95 call-out fee applies in set cases — within the first 30 days, for issues the plan doesn't cover, if the engineer can't get access, or if you ask for your annual service early.

Why does the Baxi E119 code appear?

The pressure has fallen below the minimum the boiler needs to run, so it stops. Four things commonly cause that drop.

A leak somewhere in the system — a radiator valve, a joint in the pipework, or the boiler itself — lets water escape slowly, so pressure creeps down over days or weeks. Recently bled radiators are a harmless, one-off cause: bleeding releases both air and a little water, and the gauge drops as a result. A passing or faulty pressure relief valve can weep water out through the external overflow pipe. And a failed expansion vessel can no longer absorb the water's expansion, so pressure swings up when the system is hot and drops when it's cold.

The pattern tells you which it is. A slow, recurring drop points to a leak. A single drop straight after bleeding a radiator is nothing to worry about — top it up once and you're done. What you should avoid is topping up again and again to mask a leak: every refill introduces fresh, oxygen-rich water, and that speeds up internal corrosion and sludge, which only creates more problems down the line.

Baxi E119 causes at a glance

How to fix the Baxi E119 code yourself

You can usually clear E119 by repressurising the system — it's the one repair Baxi's own guidance points homeowners to. Do it with the boiler cold, and take it slowly.

1. With the boiler off and cold, check the pressure gauge (a dial or a digital reading on the front). It should sit around 1.0-1.5 bar when cold; on E119 it will read low, near zero.

2. Locate the filling loop — usually a silver braided hose with a valve at each end, underneath the boiler, connecting the two pipes.

3. Open both valves slowly. You'll hear water flowing and see the gauge rise. When it reaches about 1.5 bar, close both valves fully.

4. Reset the boiler if it needs it, and check it fires up and runs. If your boiler has a removable filling loop, disconnect it once you're done.

Top up only once. If the gauge won't hold pressure, if it climbs back down soon after, or if E119 returns, stop there — don't keep refilling. That's the sign of a leak or a component fault that needs an engineer, not another top-up.

One safety note: E119 is a water-pressure fault, not a gas fault, so the gas emergency line isn't relevant to the code itself. But if you ever smell gas or a carbon monoxide alarm sounds — whatever code is showing — leave it alone, open the windows, get everyone out, and call the National Gas Emergency Service on 0800 111 999.

When to call a Gas Safe registered engineer for E119

Call an engineer if the pressure drops again soon after you've topped it up, if E119 keeps coming back, or if you can see water leaking or dripping anywhere. A recurring E119 points to a leak, a faulty pressure relief valve, or a failed expansion vessel — and none of those are homeowner repairs. Tracing a leak inside the fabric of the system, or working on the sealed heating circuit and its components, is a job for a Gas Safe registered engineer.

For context on cost, the average UK boiler repair is around £300, with a usual range of £120-£750 depending on the fault and where you live (Checkatrade, 2026). A simple leak or a valve is at the lower end; an expansion vessel or a hidden pipe leak sits higher. You can check any engineer's credentials on the Gas Safe Register before they start.

Smart Plan is a service plan, not insurance. An ongoing boiler module contributes towards parts and labour if your boiler breaks down in future — up to £500 a year if it's under 7 years old, or up to £200 if it's older. Those are caps, so a bigger job can cost more than the plan pays: on an older boiler, a hidden pipe leak towards the top of that £120-£750 range could sit several hundred pounds above the £200 limit, and you would pay the balance yourself. Cover is modular — you pick only the modules you want, so you don't pay for what you don't use.

A few things worth knowing before you join, so there are no surprises. Cover is for future breakdowns, not a fault your boiler is already showing — an E119 on the display today counts as a pre-existing fault and wouldn't be covered, so book a one-off repair for that. A £95 call-out fee applies in set situations: within the first 30 days of cover, for issues the plan doesn't cover, if the engineer can't get access, or if you ask for your annual service early. Call-outs are booked Mon-Fri 08:00-18:00, with an engineer attending outside those hours only for an emergency breakdown, so don't rely on cover for evening or weekend help with a routine E119. There's a 14-day cooling-off period when you join, and a 12-month minimum agreement period begins once you use a service — leaving early during that period costs the remaining months, up to 75% of the outstanding balance. We've looked after over 15,000 customers and we're from UK Boiler Company Ltd, trading since 2014. To book a one-off repair for an E119 that's showing now, or to set up cover for the future, call 0333 772 6247 or start online.

Baxi E119 fault code FAQs

E119 showing now? Book a repair — and plan ahead for the next one.

Book a one-off repair and a Gas Safe registered engineer will trace the cause of a recurring E119. Want to plan ahead? A Smart Plan boiler module contributes towards parts and labour on future breakdowns, up to your cover limit — £500 under 7 years, £200 over — with a £95 call-out fee in set cases and a 12-month agreement period once you use it. A fault your boiler already has isn't covered, so cover won't fix today's E119. A service plan, not insurance.

Helpful links

• Baxi E133 gas supply fault
• Baxi E110 overheat fault
• All Baxi fault codes
• No heating? Book a repair
• Boiler & central heating cover
• Baxi error codes (official)
• Check an engineer on the Gas Safe Register