Planar went out while running: code 29 or three blinks
Updated: 2026-11-10
In short. Code 29 (three blinks on the PU-5) means the flame went out during operation, not at start-up. Causes per the manual: too little fuel, a faulty pump or a faulty flame indicator.
Which heaters and controllers it applies to
Code 29 comes from Advers (Autoterm brand) factory documents for the Planar 2D, 4D, 8D and 9D air heaters. Codes differ by model and controller, so what you see matters:
| What you look at | What is shown | Meaning |
|---|---|---|
| Repair code table | Code 29; code 08 refers to 29 | Flame-out during operation |
| PU-5, controller without a display | 3 flashes of the red LED | Too many flame-outs during operation |
| PU-22, controller with a display | The number 29 | Permitted number of flame-outs exceeded |
| Code 78 (also 3 blinks on the PU-5) | The number 78 | Flame-out, air in the fuel system |
Three blinks is not code 03: the repair table has no such code; three blinks match codes 29, 08 and 78. Two blinks on the PU-5 are already code 13 (did not start), and 13 blinks are code 35, flame-out on a voltage dip, only on the Planar 8DM.
What code 29 means
The flame was interrupted while the heater was running. Per the factory manual the causes are: insufficient fuel supply, a faulty fuel pump, a faulty flame indicator.
What to check yourself
- Fuel line: leaks, blockage, tight clamps.
- Air intake and exhaust pipe: the passage for combustion air and exhaust must be clear.
- The amount of fuel in the tank and the fuel supply to the heater.
For code 78 the manual specifically names air in the fuel system; the checks are the same.
When a workshop is needed
- the flame-out repeats after the fuel line, air intake and exhaust were checked;
- the amount of fuel the pump delivers has to be checked and the pump replaced if necessary - per the manual a separate repair operation;
- if the heater then starts, the manual requires checking the flame indicator and replacing it if faulty.
Questions and answers
What does code 29 mean on a Planar?
Flame-out during operation: the flame in the combustion chamber went out while the heater was running.
Are three blinks on the PU-5 code 03?
No, the repair table has no such code. Three blinks match codes 29, 08 and 78.
How is code 78 different from 29?
The same flame-out, but for 78 the manual specifically names air in the fuel system.
What if the flame-out repeats?
After checking the fuel line, air intake and exhaust a workshop is needed: a check of pump delivery and of the flame indicator.
Code pages on the site
- Code 29 - code page
- Code 78 - flame-out, air in the fuel
- Code 13 - failed to start
- All Planar codes
Checked against manufacturer manuals and tables; the same facts as in our videos and articles. The decision to drive remains with the driver.
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