Code 133 in frosty weather
The condensate pipe freezes outside and the boiler can no longer start.
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Atag Error Codes
Has your Atag boiler (i, iC, E or Q series) broken down and does it show a number such as 118 or 133? On an Atag, the code is a number that tells you which safety device has shut the boiler down. Our heating engineers repair Atag gas boilers 7 days a week, with the price announced before the repair.
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Atagi, iC, E and Q series
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Atag boiler repair
Atag is a Dutch brand with a strong presence in Flanders and Brussels. Its condensing boilers are recognisable by their stainless steel heat exchanger and by a control that reacts quickly to the water flow. As soon as something goes outside its limits, the boiler blocks and shows a number.
The best known is 133: no flame after five ignition attempts. In winter it is often caused by a frozen or blocked condensate pipe, but also by the gas supply or the electrode. 118 signals water pressure that is too low, and 151 a fan that does not reach the right speed.
Our engineer checks the pressure, the pump, the electrode, the fan and the condensate drain, then gives you the price of the repair before doing it. He carries the parts most often needed on Atag boilers.
Atag boiler service
The stainless steel exchanger of an Atag is efficient, but it does not cope well with sludge and limescale. A dirty circuit makes the temperature climb too quickly (code 154) and wears out the pump.
During the service the technician cleans the burner and the exchanger, inspects the siphon, measures the combustion and tests the safety devices. You receive the service attestation.
He also tells you whether the system would benefit from a sludge filter or a flush: that is often the difference between an Atag that lasts and one that locks out every winter.
Atag error code table (i and iC series)
The codes above apply to Atag boilers of the i and iC series. Older series and the Q range may use other numbers: write down the number shown and call us.
| Code | Meaning | What the technician checks |
|---|---|---|
| 110 | Safety temperature exceeded | Water circulation, pump, sensors, heat exchanger. |
| 111 | Maximum temperature exceeded | Water flow, pump, system valves. |
| 118 | Water pressure too low | System pressure, possible leak, pump, pressure sensor. |
| 129 | Fan does not start | Fan, connectors, control board. |
| 133 | No flame after 5 ignition attempts | Gas supply, electrode, condensate drain (frozen or blocked). |
| 151 | Fan speed out of range or faulty control unit | Fan and control unit. |
| 154 | Flow rising too fast: temperature difference too large, return warmer than flow | Pump, water flow, sludge in the system. |
Code not in this table: call us, our technician knows it.
Smell of gas? Do not touch any switch, open the windows, leave the house and call 112 from outside. If 133 or 118 keeps coming back, note the number and the time it appears: it helps the diagnosis.
Typical Atag faults
Pressure dropping (118)
Leaking radiator, dripping relief valve or an expansion vessel that needs recharging.
Fan (129, 151)
Worn fan or oxidised connector, more rarely the control unit.
Overheating (110, 111, 154)
Tired pump or a system full of sludge: the water no longer circulates enough.
Sensors
A faulty sensor gives a false reading: heating or hot water becomes irregular.
What the technician does on your Atag
He checks the history
The boiler keeps its last codes: he sees whether 133 returns every night or was a single event.
He measures
Ionisation, gas pressure, fan speed, pump flow: the real cause before any part is fitted.
He repairs and explains
Price announced first, repair, combustion check, job report and invoice.
What our customers say
Where do we work?
We repair and service Atag boilers across Belgium: Brussels, Wallonia and Flanders. Give us your code and your town and we will tell you when a technician can come.
BrusselsWalloon BrabantFlemish BrabantHainautNamurLiègeLuxembourg provinceAntwerpEast FlandersWest FlandersLimburg
The brands we work with
Our technicians work on all brands: they install, service and repair appliances from the major manufacturers. For a new installation, we recommend the model that suits your home and budget.
We buy our equipment from all the major Belgian wholesalers and suppliers, including Facq, Van Marcke and Desco: genuine parts, quickly available.
Frequently asked questions
What does code 133 mean on an Atag?
The boiler did not get a flame after five attempts. Gas, the electrode or a frozen condensate pipe are the most common causes. Write the code down and call us.
Is code 118 a breakdown?
It means the water pressure is too low. If it keeps returning, there is a leak or an expansion vessel problem that the technician has to find.
What does code 151 mean?
The fan speed is outside its expected range, or the control unit is faulty. A measurement shows which part is to blame.
Why does my Atag lock out mostly when it freezes?
The condensate drain pipe can freeze outdoors: the water can no longer flow away and the boiler goes into safety mode.
Do you service Atag boilers?
Yes, as a yearly service or a repair, with the service attestation handed over at the end of the visit.
How soon can a technician come?
We offer the first free slot, often the same day depending on your town. The price is given before the work.
Your Atag shows a number?
Call us or book a slot online: a heating engineer comes to your home and finds the cause.