What does the Viessmann 299 fault code mean?

The boiler's internal clock has lost or confused its time and date, which usually affects timed heating schedules rather than the heating or hot water themselves.

How much does it cost to fix Viessmann error code 299?

Typical repair cost for the Viessmann 299 fault is £90-250 including labour.

Viessmann 299 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Real-time clock fault

From this model's manual

Verified against the Viessmann/Viessmann Vitodens 100 W B1hf B1kf 6167586 installation & service manual.

DIY fix possible

Press the reset button on the boiler control panel or switch the boiler off at its power supply for a minute, then switch it back on.Use the control dial and menu on the boiler to check and set the correct time and date.Check that your heating and hot water timer settings are still correct, then watch to see if the code clears. If it returns, call a Gas Safe registered engineer.

Find a Gas Safe engineer

Search the official register →

Boiler cover options

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner

Domestic Appliance Guard

Unlimited call-outs, 24/7 helpline, no price-hike promise

Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

F.28View →F.22View →

All 151 fault codes on the Vitodens 100-W B1HF-25

Seeing a different code? Every code this model can display, in one place.

7 8 11 12 13 14 15 16 29 30 49 50 57 58 59 62 63 64 65 67 68 69 70 71 72 73 74 75 77 78 87 89 91 92 95 100 102 103 104 142 161 162 163 176 182 183 184 185 345 346 347 348 349 350 351 352 353 354 355 357 359 361 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 395 396 399 400 401 402 403 404 405 406 408 410 416 417 418 425 446 447 448 449 451 452 453 454 455 456 457 458 461 462 463 464 467 468 471 474 477 517 527 528 540 544 545 574 575 576 577 578 579 682 683 684 694 738 766 767 799 979 980 981 982 E10 E12

The boiler's internal clock has lost or confused its time and date, which usually affects timed heating schedules rather than the heating or hot water themselves.

What the manual says

DIY fix possible

Avoid the next call-out bill

Related fault codes

All 151 fault codes on the Vitodens 100-W B1HF-25

Related guides you might find useful

No hot water but heating works

Boiler won't turn on: 9-step checklist

Is boiler cover worth it?

Recently viewed