Freezing and Winter WeatherUpdated 20 days ago
Using Your Modtub Outdoors in Winter Weather
If you plan to keep your Modtub outside during freezing temperatures, please follow the steps below to prevent damage. Freezing-related damage is not covered under warranty, so proper winter maintenance is essential.
1. Bring the Chiller Indoors + Use the Bypass Hose
When temperatures drop below 32°F (0°C):
Bring the chiller inside.
Install the chiller bypass hose to maintain flow.
Freezing inside the chiller can permanently damage internal components.
Click here to learn how to install the bypass hose.
2. ALWAYS Keep Water Flowing
The most important rule: never let water sit still in freezing temps.
Keep the pump running at all times.
Check flow regularly, especially overnight or during long freezes.
If needed, run the system 24/7 until temperatures rise.
Standing water freezes fast—and ice expansion can crack hoses, fittings, or the filter housing.
3. Remove the Filter Cartridge in Freezing Conditions
Filters slow down flow, especially when dirty. Reduced flow increases freeze risk.
During freezing weather:
Remove the filter completely.
Let water pass freely through the housing.
Make sure the housing is sealed and O-ring is seated properly.
Most winter damage we’ve seen has been to the filter housing, due to restricted flow.
4. Expect Slight Tub Expansion/Contraction
The tub may expand in warm temps and contract slightly in cold temps. This is normal and temporary.
Temperature shifts can affect the way the lid fits or how fittings align.
The tub returns to normal shape once temperatures stabilize.
5. Keep the Unit Sheltered When Possible
The tub can stay outdoors, but extra protection helps:
Place it under a covered patio or awning.
Avoid snow/ice buildup on hoses and fittings.
Prevent water from pooling around the pump or filter housing.
6. Check Your Setup Daily
During freeze events, do quick check-ins:
Confirm water is circulating.
Make sure hoses aren’t stiff or forming ice.
Look for frost or slow flow around the filter housing.
If flow slows, remove the filter immediately and check for blockages.
7. Power Outage Warning
If temperatures are below freezing and power goes out:
Water inside hoses and components can freeze quickly.
Disconnect hoses, drain them fully, and bring the chiller/pump indoors.
Drain the tub if necessary for extended outages.
8. Warranty Reminder
Damage from freezing—such as cracked filter housings, burst hoses, or chiller/pump damage—is not covered by Modtub’s warranty.
9. Additional Resources
Watch the videos below for everything we currently know about winter setups, freezing, and outdoor use.
January 2025
December 2023