Baxi E119 fault codewhat it means and how to fix it
Low water pressure on the selector-switch Baxis — Duo-tec Combi HE, Platinum, Megaflo System HE A. Shown as E1 then 19. Repressurise; no reset is needed.
Take care
What does the gauge on the facia read?
The right answer depends on what you can see. Pick the one that matches.
Choose the option on the left that matches what your appliance is doing, and the answer for that case appears here.
Below 0.5 bar
The code is accurate. Top up to 1 to 1.5 bar cold and the boiler will run.
If you are doing this more than twice a year, ask for a leak check and the expansion vessel charge.
Around 1 bar or above, but E119 stays
The pressure switch is not making or its wiring is off. The boiler is reading a switch, not a gauge, and the two disagree.
Engineer job; the switch is cheap and the diagnosis is quick.
It needs filling every day or two
A leak fast enough to be doing damage somewhere, or a relief valve stuck open.
Stop refilling, switch the boiler off and get it looked at.
What E119 means
E119 belongs to the older of Baxi's two three-digit generations: boilers with a rotary ON/OFF/RESET selector and a two-character display, which show it as "E1" alternating with "19". The Duo-tec Combi HE A, Platinum Combi and Platinum+ manuals all define it the same way — "E119 is displayed when the primary water pressure is less than 0.5 bar" — and the table entry is "Water Pressure Switch Not Operated".
The user guide for the Platinum is the one that tells the householder what to do: "After repressurising the system the boiler should operate. Your installer will be able to advise you about the method of repressurising." Nothing about the selector switch is mentioned, because E119 is not one of the three codes Baxi allow you to reset on these boilers; it goes when the pressure comes back. A correction to what this page used to say. It presented E119 as a switch-based reading and E118 as a measured one, and drew a diagnostic distinction from that.
Baxi's manuals do not support it: the Platinum+ 40 parts diagram calls the component a "Water Pressure Sensor" while its error table says "Switch", and the 600 Combi, which shows E118, names a "Hydraulic pressure switch". The real difference between the two codes is the display generation, nothing more. What the flowcharts do say is useful: if the system is above 0.5 bar and E119 persists, the switch and its wiring are the suspect, because a device that is either made or not made can stick.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| The system has lost water | Radiator valve glands, a pinholed radiator, a joint under a floor, or the boiler's own pressure relief valve passing to the outside pipe. Sealed systems do not consume water; a falling gauge is always a leak or a flat vessel. | Common |
| Expansion vessel needs recharging | The Duo-tec and Platinum carry the vessel at the back of the case where it is awkward to reach and easy to skip at a service. A flat vessel lifts the relief valve on every heat-up and the pressure is gone by morning. | Common |
| Water pressure switch stuck or wiring adrift | Baxi's fault-finding sequence for E119 checks the system pressure first and then the switch and its connections. A boiler showing E119 with the gauge at 1.2 bar has a switch problem, not a water problem. | Occasional |
| Air in the system after work | A refilled system settles as air is bled off, and the pressure that was fine on the day falls over the following week. One extra top-up is normal; a third is not. | Occasional |
What to try yourself
Let the system cool and read the pressure gauge on the boiler facia. Baxi's Platinum user guide expects between 1 and 2.5 bar; E119 shows below 0.5.
Find the filling loop — usually a braided hose with two valves under the boiler on these installations. If the hose is not connected, the installer may have left it loose nearby; connect it hand-tight before opening anything.
Open both valves slowly until the gauge reads between 1 and 1.5 bar, then close both firmly.
Never fill with the heating running or the water hot, and do not go past 2.5 bar. The relief valve opens at 3 bar and will empty your top-up onto the ground outside.Watch the facia. On these boilers E119 disappears as soon as the pressure switch makes; there is no reset to perform. If a different code appears, look that one up instead.
Bleed any radiators that are cold at the top and top up again if the gauge drops. Write the date on the boiler; the interval between top-ups is the only leak detector you own.
Get a Gas Safe registered engineer to look at your Baxi E119
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What it costs to fix
Typical repair cost
£0–£300
Time on site
10 minutes
Free to top up. Water pressure switch fitted around £110–£170. Leak trace from £90. Expansion vessel recharge or replacement £120–£300.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
We may earn a commission if you buy a part through one of these links. It does not change what you pay, and it does not affect which parts we list.
Expansion vessel (8 litre, sealed system)
EV-8L£35–£85Plumbing merchant
Price checked 28 September 2026
Pressure relief valve, 3 bar
PRV-3B£18–£42Plumbing merchant
Price checked 28 September 2026
Baxi / Potterton / Main hydraulic pressure switch (600, 800, Assure, Eco Compact)
5114748£40–£90Authorised Baxi parts distributor
Price checked 28 September 2026
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Related Baxi fault codes
- E118Get it checkedLow water pressure on the digital-display Baxis: 600, 800, Duo-tec 2, Compact, Assure, Megaflo. Defined by Baxi as primary pressure under 0.5 bar. Repressurise and it clears itself.Related: water pressure
- E.02.07Usually simple to fixLow water pressure made permanent on the Baxi 200/400 Combi and Combi 2, after A.02.06 or H.02.06 has been showing. Repressurise to 1 to 1.5 bar and reset; Baxi say you can do it yourself.Related: water pressure
- E117Get it checkedPrimary water pressure too high, on the Duo-tec 2 and EcoBlue Advance. Usually an overfilled system or a flat expansion vessel. Let some water out and it clears.Related: water pressure
- E430Get it checkedA temporary water-pressure fault on the 600, 800 and Compact family, from Baxi's professional error-code table. If it comes with a crossed flame symbol the pressure self-test has failed.Related: water pressure
- E133Get it checkedBaxi's ignition lockout: "the gas supply has been interrupted, ignition has failed or the flame has not been detected". Check the gas is on, reset once. If it returns, stop.Related: same brand
- E.04.10Get it checkedIgnition failure on the Baxi 200/400 Combi and every Combi 2: the burner would not light after its allowed attempts. Baxi's own quick guide names it the frozen-condensate code you can fix yourself.Related: same brand
Own a Baxi boiler? Save it and its codes come first next time.
Related guides
Common questions about Baxi E119
Why does my Baxi say E119 when others say E118?
Yours has the rotary selector and the two-character facia; E119 is the low-pressure code for that generation (Duo-tec Combi HE, Platinum, Megaflo System HE A). Later Baxis with a digital display and Reset button use E118 for the same fault. Both mean primary pressure under 0.5 bar.
Do I turn the selector to R after filling?
No. Baxi only offer the selector reset for E110, E130 and E133 on these boilers. E119 clears on its own once the pressure switch sees enough water. If it does not, the switch is the problem.
How is E119 shown on the display?
As two halves, because the facia has room for two characters: E1, then 19, then E1 again. It is one code, not two faults.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.