Resideo Announces Communication Issues With Some 5821s

Some Resideo 5821 wireless flood and temperature sensors manufactured between July and October of 2023 may not transmit properly. They may fail to learn into the alarm panel or fail to transmit when an alarm occurs. Affected units can be returned to the vendor for refund or replacement.

The 5821 is a versatile wireless sensor from the Resideo (formerly Honeywell) 5800 Series sensor line. Alone, it can monitor for high and low temperature conditions. It can also be used with either a remote temperature probe, or a remote flood-sensing probe. The use of either remote probe allows the 5821 to monitor harsh conditions that the circuitry of the transmitter itself cannot endure.

The date code for the 5821 is located on the box it comes in, and should also be visible as a sticker or a printed series of numbers on the circuit board itself. The date code consists of a 2-digit number for the year and a 2-digit number for the week of that year.

In 2023, between week 30 and week 40*, a manufacturing issue caused 5821 transmitters to be produced with a defect that caused affected units not to transmit properly. These units may never learn into the panel, or they may fail to transmit when a monitored condition occurs. This could result in damage to a home or business.

The date codes included in this notice are 2330 (2023, week 30) through 2340 (2023 week 40). Any unit with date code 2342 or later is not affected by this issue. July 24, 2023 begins week 30, and October 8, 2023 ends week 40.

If you recently purchased a 5821 from Alarm Grid, check the date code on the unit. If it falls within the affected range, contact us at support@alarmgrid.com and we will happily provide you with a warranty replacement. You can read the full notification from Resideo here. If you received a unit that would not learn into the panel initially, it is likely that we have already performed troubleshooting with you and have at least begun the warranty replacement process.

For customers who may not read our blog, Alarm Grid is reaching out to anyone who purchased this product from us from March 2023 until now. We will provide information on the notification, how to check the date code, and will gladly replace any units affected.

*Important Note: When this issue was discovered, production of the 5821 was halted and the issue was investigated to discover the root cause. There was no production of the 5821 during 2023 week 41, which accounts for the seemingly "lost week" missing in the above referenced announcement.