{"id":961,"date":"2026-10-26T13:45:19","date_gmt":"2026-10-26T13:45:19","guid":{"rendered":"https:\/\/content.agfmfg.com\/blog\/?p=961"},"modified":"2026-10-26T13:48:32","modified_gmt":"2026-10-26T13:48:32","slug":"prepare-your-fire-sprinklers-auxiliary-drains-for-winter","status":"publish","type":"post","link":"https:\/\/content.agfmfg.com\/blog\/prepare-your-fire-sprinklers-auxiliary-drains-for-winter\/","title":{"rendered":"Prepare Your Fire Sprinkler’s Auxiliary Drains for Winter"},"content":{"rendered":"

For building owners, facility managers, and fire protection contractors, preparation isn\u2019t just a seasonal event. It continues throughout winter. A drain emptied in October can collect more water in November, December, and\/or\u00a0\"\" January. A heater can fail during a weekend cold snap while the building is empty. Plan for those possibilities before the first freeze to help prevent accidental system trips, flooding, facility damage, and system impairment.<\/p>\n

Prepare fire sprinkler systems for winter by verifying heat or freeze protection, removing accumulated water from dry and preaction system auxiliary drains, and maintaining a schedule that continues throughout cold weather. Assign trained personnel to each task and confirm that alarms and monitoring notifications reach someone who can respond.<\/p>\n

Why can dry fire sprinkler systems freeze?<\/h2>\n

Dry fire sprinkler systems use pressurized air or nitrogen in the distribution piping during normal operation. However, condensation and water remaining after testing or system operation can collect inside the piping. Auxiliary drains, also called low point drains or drum drips, provide a way to remove water from trapped sections.<\/p>\n

When collected water freezes, expansion can damage drains, valves, and piping. A broken auxiliary drain can release air pressure and trip the dry valve, allowing water into the system and potentially out through the break. The result can include flooding and an impairment while repairs are completed.<\/p>\n

<\/h2>\n

What should a fire sprinkler winter preparation plan include?<\/h2>\n

<\/p>\n

1. Verify heat where water is present<\/h3>\n

Maintain at least 40\u00b0F (4\u00b0C) in areas containing water filled sprinkler piping that needs protection from freezing, unless another approved means of freeze protection applies. Include dry valve rooms and enclosures in the review because portions of a dry system still contain water.<\/p>\n

Have heating equipment serviced before cold weather. Check conditions near vulnerable piping, especially beside exterior walls, loading doors, and other sources of cold air. A thermostat elsewhere in the building may not reflect the temperature at the auxiliary drain.<\/p>\n

2. Correct building conditions that increase exposure<\/h3>\n

Inspect doors, windows, roof hatches, and wall penetrations for drafts. Repair damaged building insulation and confirm that doors close properly. Pay particular attention to vacant spaces and areas where heating schedules or building use have changed.<\/p>\n

Ask your fire protection contractor to review any location where adequate freeze protection is uncertain.<\/p>\n

3. Locate and service every auxiliary drain<\/h3>\n

Review the drain location sign or map at the dry valve and verify it against the installed system. Make sure each drain is identified and accessible. Include drains above ceilings, behind stored materials, and in areas that require special access.<\/p>\n

Have qualified personnel remove accumulated water using the instructions for the installed assembly and system. For a traditional assembly with two valves, correct valve sequencing matters. Opening both valves at once can release system air and cause an unintended trip. AGF\u2019s auxiliary drain maintenance guide<\/a> provides additional background.<\/p>\n

4. Check the air supply and freeze protection equipment<\/h3>\n

Have the contractor review the compressor, air maintenance equipment, and any air dryer or nitrogen equipment serving the system. Investigate unusual compressor cycling, pressure changes, or recurring supervisory signals.<\/p>\n

For heated auxiliary drain cabinets, check the power supply, heater operation, cabinet condition, and installed alarms. Arrange inspection and testing of any listed heat tracing or antifreeze system under the applicable requirements and manufacturer instructions.<\/p>\n

5. Establish a service schedule and record results<\/h3>\n

Assign a responsible person and a backup for drain service, temperature checks, and alarm response. Record each drain\u2019s location, service date, water discharged, and any follow-up needed. Those records help the contractor identify drains that collect water quickly and adjust the maintenance schedule.<\/p>\n

6. Prepare for weekends and severe cold<\/h3>\n

Confirm who will respond outside normal business hours. Keep contractor contact information available and review the facility\u2019s impairment procedure before a problem occurs. During extended cold or a heating failure, reassess vulnerable areas and respond to abnormal conditions promptly.<\/p>\n

<\/h2>\n

How often should auxiliary drains be emptied in winter?<\/h2>\n

Auxiliary drains in dry pipe systems need attention after system operation, before freezing weather, and as needed throughout the season. A single fall visit does not ensure the drains will stay empty all winter.<\/p>\n

NFPA 25 addresses these maintenance requirements. Its explanatory annex guidance describes operating auxiliary drains daily initially after system operation and when preparing for cold weather. The interval may be reduced when repeated checks show little or no water accumulation. Use the results of those checks to establish an appropriate ongoing schedule with your contractor.<\/p>\n

Have your fire protection contractor establish the appropriate schedule using NFPA 25, manufacturer instructions, actual water accumulation, and site conditions. Reassess that schedule after testing, system operation, or a change in operating conditions.<\/p>\n

Which AGF products can help support consistent winter maintenance?<\/h2>\n

Select auxiliary drain equipment based on its location, water accumulation, power availability, and the facility\u2019s ability to provide service.<\/p>\n

<\/h2>\n

Heated auxiliary drain cabinets and automatic draining<\/h2>\n

COLLECTanDRAIN\u00ae<\/span> heated auxiliary drain cabinets<\/a> help protect the enclosed drain from freezing. The models provide different levels of draining assistance.<\/p>\n

 <\/p>\n\n\n\n\n\n\n\n
\n

Model<\/strong><\/h3>\n
\n<\/td>\n

\n

How it manages collected water<\/strong><\/h3>\n
\n<\/td>\n<\/tr>\n<\/thead>\n

5400<\/strong><\/td>\nHeated cabinet with manual draining. Personnel still empty the drain.<\/strong><\/p>\n
\n<\/td>\n<\/tr>\n
5450<\/strong><\/td>\nHeated cabinet with a design that sheds excess condensation when the collection assembly reaches approximately 80% capacity.<\/strong><\/p>\n
\n<\/td>\n<\/tr>\n
5500<\/strong><\/td>\nHeated cabinet with fully automatic draining and on-demand local or remote operation.<\/strong><\/p>\n
\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Include cabinet heaters, controls, and alarms in the maintenance plan. Equipment selection should also account for outdoor exposure and installation requirements.<\/p>\n

<\/h2>\n

Remote monitoring with AGFConnect<\/span><\/h2>\n

AGFConnect\u2122<\/a> uses wireless sensors, a gateway, and a monitoring platform to notify designated users when monitored auxiliary drains need attention. It operates without requiring integration with a fire alarm panel or building management system.<\/p>\n

Remote alerts can help teams direct service to the drain that needs it, especially across large facilities or multiple buildings. Confirm connectivity and notification recipients before winter, maintain the required subscriptions, and assign someone to respond. Personnel still need to arrange draining when the monitored assembly requires manual service.<\/p>\n

<\/h2>\n

Flood protection with the Model 5900FE<\/h2>\n

The Model 5900FE Flood Eliminator<\/a> installs above an auxiliary drain and is designed to shut off the high-velocity water flow that can follow a drain break and system trip. It provides an additional measure to limit flooding from a failed drain. Routine draining and freeze protection remain necessary.<\/p>\n

<\/h2>\n

Common questions about winter fire sprinkler maintenance<\/h2>\n

<\/h4>\n