Follow the water and the power together. A well, heat trace, pump or heating control may stop protecting the house when electricity fails.
1. Follow the exposed parts of the water system
Trace accessible pipes from the source to the fixtures. Note unheated spaces, exterior-wall routes, outdoor taps, tank connections and building entries. These transitions often deserve more attention than the middle of a buried run.
National Weather Service guidance highlights pipes in cold or exterior locations and the importance of knowing the main water shutoff. Plan how to isolate a suspected leak and whom to call. Do not wait for a frozen valve to discover that it is inaccessible.
NWS · Home preparedness for prolonged cold ↗2. Write down what needs electricity
A fuel-fired heating system may still rely on a fan, controls or circulation pump. A well pump and an electrically protected pipe are obvious dependencies; a treatment control or alarm may be less obvious. Make an essential-load list with operating power and, where relevant, starting requirements.
Decide how long each critical function must operate during an outage. Use the energy budget for battery planning and equipment documentation for starting power. Do not assume the daily energy result proves that an inverter can start the largest motor.
3. Treat an empty house as a separate scenario
A lived-in house has people who can notice a fault. A vacant house may lose heat for much longer without intervention. Ask the heating and plumbing professionals for an equipment-specific shutdown or winterisation procedure if the building will be unheated.
Do not casually drain heating equipment, water heaters, filters or pressure systems. Some devices have startup, isolation or freeze-protection requirements that are not obvious from their appearance. Keep the approved procedure with the equipment records.
4. Check again when temperatures rise
An ice blockage can conceal a damaged pipe until thawing begins. Inspect accessible cold-exposed lines and look for leakage when flow returns. If you suspect a freeze or rupture, isolate water where safe and contact a plumber. Do not use an open flame to thaw pipes.
Keep a written incident note: location, temperature, power status and what changed. That evidence helps improve the vulnerable detail before the next cold spell.
NWS · Checks after cold weather ↗A practical winter walkthrough
| System | Check before frost | Record |
|---|---|---|
| Outdoor water | Isolation and specified drainage procedure | Valve location and responsible person |
| Cold-space pipes | Exposure and approved protection | Photo and route sketch |
| Heating | Service and power dependencies | Operating and shutdown instructions |
| Well and treatment | Pumps, controls, exposed fittings | Freeze and outage instructions |
| Backup power | Safe location and essential loads | Test date and approved connection |
Worked example
An outage energy estimate
Suppose heating controls and circulation average 80 W continuously, with another 50 W of essential loads.
(80 + 50) W × 24 h / 1,000 = 3.12 kWh per day
This hypothetical energy total is only the starting budget. Actual cycling, battery losses, pump surge and the heat source’s requirements must be checked separately.
What to have ready
- Accessible shutoff and emergency contacts
- Cold-exposed pipe list
- Heating and water-system instructions
- Essential electricity budget
- Plan for an unoccupied building
Common mistakes
- Assuming fuel heating works without electricity.
- Treating insulation as an unlimited heat source.
- Forgetting to inspect for leaks after a thaw.
Reference check: 5 September 2026. Sources include US public agencies. Principles are general; regulations and design values must be checked where you live.Worked examples use stated hypothetical inputs.