Sub-Zero Designer Code 15-2-00: Zone 2 relay not switching on

What 15-2-00 means

Code 15-2-00 appears on Designer units like the DEC3050R column and DET3050CI tall model when the control-board relay that switches cooling for zone 2 reads open. Classic BI models including the BI-36U/S and BI-48SD/S use the same code for the freezer relay open. The control has called for cooling but sees no closed path through that relay, so cooling for the section may not start. You would typically notice zone 2, or the freezer on a BI, slowly warming while other sections stay cold.

Common causes of 15-2-00

Relay on the control board stuck open
Open wire or loose plug on that relay circuit
Control board output not switching

✓ One safe check you can try

1) Read the freezer or zone 2 temperature with a thermometer. 2) Move frozen food to another freezer or a cooler with ice if it is warming. 3) Keep that door firmly shut. 4) Switch the breaker off for a minute and back on. 5) Call us quickly if 15-2-00 comes back.

! Why to stop there

Relay checks involve line voltage at the control board.
Board repairs need the correct platform part.
Loose board connectors must be secured properly to avoid repeat trouble.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Refrigerator codes

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15-2-0015-2-00 questions

Does 15-2-00 affect only the freezer?

On a Classic BI it concerns the freezer relay. On Designer units it concerns zone 2. Other sections have their own relays and may keep cooling normally while this one warms.

How urgent is 15-2-00?

Quite urgent if the freezer or zone 2 is warming, because frozen food can start to thaw within hours. Move food to another freezer and book service quickly.

What does the technician test?

We check the relay output on the control board, its plugs and the wiring on that circuit, then repair the connection or replace the board. The price is in writing first.