FAQ
TL;DR: De Dietrich Lumea MPX 20/24 error E133 often clears with a precise 2‑second reset; "Reset as instructed… at least 2 sec." Perform the correct reset and the boiler restarts. [Elektroda, zales.vip, post #18830605]
Why it matters: This helps owners of this model fix E133 fast and avoid avoidable service costs.
Quick Facts
- E133 can follow a pressure drop; the meter‑side reducer’s safety valve may trip. Unlock it, then reset the boiler. [Elektroda, marcin7sobiech, post #20207105]
- Correct reset: press and hold the boiler’s power button for 2 seconds. [Elektroda, maciek190, post #19045141]
- Auto‑calibration: hold i/p + heater+ for 6 seconds; if a room thermostat blocks buttons, temporarily disconnect it at M2 with power off. [Elektroda, zales.vip, post #18910813]
- A mainboard was quoted at 560 PLN (+150 PLN visit), but reseating connectors restored operation. [Elektroda, lukg86, post #18831455]
- The reducer lever sits by the gas meter (often an outdoor box); lift until a hiss to unlock. [Elektroda, marcin7sobiech, post #20207105]
What does error E133 mean on the Lumea MPX 20/24?
E133 indicates ignition failed because gas is not reaching the boiler. A tripped reducer near the meter can block gas after a pressure drop. Unlock the reducer, then reset the boiler. [Elektroda, marcin7sobiech, post #20207105]
How do I perform the correct E133 reset?
Press and hold the boiler’s power button for 2 seconds. Release and allow the restart attempt. "By holding down the power button for at least 2 sec." [Elektroda, zales.vip, post #18830605]
My reset isnt workingcould timing be the issue?
Yes. Users report success when holding for a precise 2 seconds. Focusing on exact timing triggered the reset and restored operation. [Elektroda, dbst, post #19038549]
How do I unlock the gas reducer after a shut-off?
This opens the safety valve so gas flows again.
- Confirm the upstream meter valve is open and the installation is tight.
- Lift the small lever on the reducer until you hear a hiss.
- After gas flows, perform the boiler reset. [Elektroda, marcin7sobiech, post #20207105]
Where is the reducer lever located?
You’ll find it next to the gas meter, often in a metal box by the fence. Lift the small lever upward until you hear a hiss. [Elektroda, marcin7sobiech, post #20207105]
I reopened the gas valve, but E133 persistswhy?
The meter‑side reducer may stay locked after a pressure drop. Until you lift its lever to reset it, no gas reaches the boiler and resets won’t help. [Elektroda, marcin7sobiech, post #20094036]
Do room thermostats sometimes disable the boilers buttons?
They shouldn’t. If buttons seem blocked, temporarily disconnect the external regulator/thermostat at the M2 strip with power off. Then run auto calibration and reset. [Elektroda, zales.vip, post #18910813]
Can I reset the boiler from the room thermostat?
No. Using the thermostat’s reset only resets the thermostat. The boiler still requires its own panel reset or equivalent action. [Elektroda, Branchy, post #18910546]
Is a motherboard replacement usually necessary for E133?
Not always. One case was quoted 560 PLN for the board plus 150 PLN service, but reconnecting internal wiring restored operation. Try simple checks first. [Elektroda, lukg86, post #18831455]
Could venting the gas line resolve E133 after shut-off?
Yes, if air remained in the line. An installer briefly passed gas to purge the boiler, and it worked. Ask a qualified person to handle purging. [Elektroda, cielok123, post #18938891]
Are dirty ignition electrodes a possible cause of E133?
Possibly. A commenter suggested the technician simply cleaned the electrodes and the boiler ran. Ask service to inspect and clean them. [Elektroda, ROWE, post #18834612]
Why does my display blink and alternate screens with E133?
That symptom matched E133 in a reported case after a gas shut‑off. The unit flashed and wouldn’t heat water until reset and gas flow returned. [Elektroda, lukg86, post #18830453]
How do I run auto calibration on a Lumea MPX?
Hold the i/p and heater+ buttons together for 6 seconds. If a connected thermostat blocks buttons, disconnect it at M2 first with power off, then calibrate and reset. [Elektroda, zales.vip, post #18910813]
What should I try if a 2-second reset still does nothing?
Turn off power and have a tech reseat internal connectors. In one case, disconnecting and reconnecting wires brought the boiler back without parts. [Elektroda, lukg86, post #18831455]
