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Viessmann · Error codes

Viessmann Vitocrossal 200 F.473 — No Call for Heat

F.473

Needs attentionVitocrossal 200 CI2 commercial condensing boilers (fault codes, SI 6175 797 - 23)

No call for heat. Communication error, heat management unit (HMU). Check connecting cable between burner control unit (BCU) and HMU.

Applies to

This communication or network fault code is displayed by the CI2 control (F-codes) on CI2 models (CI2-399 through CI2-2000), as documented in Vitocrossal 200 CI2 Service Instructions, doc 6175 797 - 23 (04/2026) (6175 797 - 23). Codes can differ between controller generations, so always check the manual that matches your unit.

Controller: CI2 control (F-codes). Source manual: 6175 797 - 23 (2026-04).

Why a code is not a diagnosis

A communication code involves the link between controls (cascade, remote, sensors on a bus). Another unit being off, a wiring fault or an address conflict can all produce it.

Safe things to observe

  • Check that every appliance in a multi-unit plant has power.
  • Report the code together with any other codes on the system.

Do not

  • Do not re-address or rewire control networks yourself.

How professional service helps

  1. A technician verifies power, wiring and settings across the connected units.
  2. Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.

Where ROMA provides on-site service

On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.

See all service areas

Parts and service

Parts commonly involved

These parts appear in the documented text for this alert. A code reports a condition, not a failed part — a technician confirms the cause by testing before anything is replaced.

Service for this alert

  • Gas Boiler Repair

    Licensed gas technicians from ROMA Heating & Cooling diagnose and repair residential and light-commercial gas boilers across…

Every boiler part explained — what it does, how it fails and what a technician checks.

Documented for Viessmann Vitocrossal 200 (CI2).

Frequently asked questions

Can I clear this code myself?

Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.

Boiler locked out? Call with the alert text ready.

The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.

On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.

Sources and verification

Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.

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