Marantec 122945, Transformer Box Synergy 360
The Marantec 122945 transformer box is the power conversion assembly used inside select Synergy garage door opener heads. Its job is to take incoming household power at the operator and provide the stable low-voltage supply the opener electronics need to run. When this part fails, the opener may appear completely dead, reset intermittently, lose accessory power, or behave inconsistently even though the wall outlet has power. This is not a decorative housing part and it is not the logic board; it is part of the electrical power path inside the opener. For that reason, the 122945 should be matched by the exact part number printed on the original transformer box or by the Marantec parts diagram for the operator. Synergy models can look very similar from the outside, but transformer boxes vary by model family and generation.
Compatible With
- Marantec Synergy 360 garage door operators when the parts diagram calls for 122945
- Marantec Synergy 280 references where 122945 is listed as the correct transformer box
- Select Marantec Synergy residential opener heads using the 122945 transformer box
- Not for Synergy 370/380 transformer applications that call for 105470
- Not for Synergy 260/270 transformer applications that call for a different transformer box
- Not a universal transformer for LiftMaster, Genie, Linear, Chamberlain, Craftsman, or other opener brands
Features and Specifications
| Manufacturer | Marantec |
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| Product Type | Transformer box / power module |
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| Part Number | 122945 |
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| Application | Low-voltage power supply service part for select Synergy openers |
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| Compatible Operator Type | Residential garage door opener |
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| Operator Family | Select Marantec Synergy 280 / Synergy 360 references |
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| Notes | Match by original part number and model parts diagram |
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Also Known As / Related Part Numbers
- 122945
- MAR-122945
- Marantec 122945
- 122945 transformer box
- Synergy 360 transformer box
- Synergy 280 transformer box
- Marantec transformer box assembly
Technician Note
Match this Marantec part by the model label, original part number, rail type, frequency, or parts diagram before ordering. Marantec used similar-looking parts across several generations, and small differences in receiver frequency, housing shape, rail style, or sensor hardware can prevent a proper repair.
Before Ordering Checklist
- Confirm the Marantec model number on the opener head or parts diagram.
- Compare the original part number to the number shown on this product page.
- For rail parts, confirm chain versus belt rail and standard versus heavy-duty rail.
- For receivers, confirm the operating frequency and remote family before ordering.
- For photo eye parts, repair the safety system properly and never bypass required sensors.
Professional Advisory
Garage door openers can involve spring-loaded doors, moving drive systems, low-voltage safety circuits, and internal electrical parts. If the repair involves power diagnosis, failed safety devices, a door that will not balance, or an opener that moves unpredictably, have a qualified garage door technician inspect the system before returning it to service.
Product Questions and Answers
What does the Marantec 122945 transformer box do?
It supplies the low-voltage power used by the opener electronics and accessories in supported Marantec Synergy operators.
Which openers commonly use part 122945?
It is commonly associated with Synergy 360 and some Synergy 280 references where the Marantec parts diagram lists 122945.
Is this the same as the control board?
No. This is the transformer box power module, not the control board, radio receiver, or complete motor head.
Can I use this on Synergy 370 or Synergy 380 openers?
Do not assume that fit. Synergy 370 and 380 transformer applications commonly use a different transformer part number, so verify the original part.
Should a technician install this part?
Yes, electrical diagnosis inside an opener should be handled by a qualified garage door technician, especially if the unit is dead or has power issues.
