A tank water heater holds roughly 150 to 250 litres of water. Here is how to use it as emergency water safely in an outage, and when not to.
- A tank water heater stores water you can use if the supply fails.
- Turn off power or gas and the cold water supply to the tank first, then drain from the drain valve.
- Treat the water before drinking, and do not use it if it may be contaminated.
Many homes hold a lot of water in the tank. Tank sizes vary, so check yours.
Steps
- Turn off the electricity or gas to the heater.
- Shut off the cold water supply to the tank.
- Let the water cool.
- Open a hot tap in the house to let air in.
- Open the drain valve at the bottom and fill clean containers.
Is it safe to drink?
Treat it first, and avoid it if you suspect contamination or have a boil advisory. See tap water safety.
Better for
Washing, flushing and, once treated, drinking. See sanitation.
Plan ahead
Know where the valves are before an outage. Electric heaters: power needs.
Quick comparison
| Brand | Best for |
|---|---|
| BBerkey | Countertop gravity filter systems |
| FFrizzlife | Home countertop and under-sink filters |
| LLifeStraw | Portable filters for backup and travel |
Gravity filters for stored or questionable water, no power needed.
- Gravity-fed, no pump needed
- Check which contaminants each model is rated for
- Plan how you will refill and clean it
Countertop and under sink filters, and emergency water options.
- Systems for daily home use
- Compare certifications and filter life
- Check replacement cost
Compact filters for a go bag or kit.
- Straw, bottle and larger formats
- Handy as a backup, not your main supply
- Check exactly what each model removes
Quick answers
How much water is in a water heater?
Often about 150 to 250 litres. Check your tank.
Is it safe to drink?
Treat it first. Avoid it if contamination is possible.
What do I do first?
Turn off the power or gas and the cold supply to the tank.