An empty house in a Colorado winter is a frozen pipe waiting for a cold snap. Nobody is there to hear the drip or notice the ceiling stain, so a small split can run for days. If a property will sit vacant, pick one of two approaches and do it properly.
Option 1: keep the heat on, turn the water off
This is the right choice for most short or medium vacancies, like a rental between tenants, a house on the market, or a long trip.
- Keep the thermostat at 55°F or higher. Make sure the furnace has a fresh filter and the thermostat batteries are good.
- Shut off the main water valve, then open a faucet on the lowest floor to drain pressure off the lines. If a pipe does freeze, very little water can escape. How to find your main shutoff →
- Set the water heater to vacation or pilot. If you'll drain it, turn an electric heater off at the breaker first.
- Open cabinet doors under sinks on exterior walls so heat reaches the pipes.
- Have someone check the house regularly, and after every cold snap. A smart thermostat that alerts you when the temperature drops, and a few inexpensive leak sensors, are worth it for a property you can't visit often.
Option 2: fully winterize the plumbing
For a property that will sit empty with the heat off, or for months at a time, the plumbing needs to be emptied so there's nothing left to freeze.
- Shut off the main water and turn off the water heater (power or gas).
- Drain the water heater completely.
- Open every faucet, hot and cold, including tubs, showers, and outdoor faucets, and flush every toilet to empty the tanks.
- Blow out the supply lines with compressed air, so water doesn't stay trapped in low spots.
- Pour non-toxic plumbing antifreeze (propylene glycol, the "RV" type) into every sink, tub, and shower drain, floor drain, and toilet bowl to protect the traps.
- Disconnect and drain the washing machine hoses, the ice maker line, and any water filter housings.
- Tag the main valve and the water heater: "Winterized. Do not turn on."
Homes with a boiler and hot-water baseboard or radiant heat need extra steps, because the heating loop holds water too. Don't shut the heat off in one of those without having the system protected.
Don't forget outside
- Get the sprinkler system blown out and the backflow preventer drained.
- Disconnect hoses and drain outdoor faucets. How to winterize outdoor faucets →
- Close crawl-space vents and seal drafts near pipes.
Check your insurance policy
Many homeowner and landlord policies have conditions for vacant properties, such as maintaining heat or shutting off and draining the water. Freeze damage in a vacant home can be denied if those conditions weren't met. Read the vacancy section of your policy, or call your agent, before the property sits empty.
Bringing it back in spring
Close all the faucets and drain valves, open the main slowly, and let the lines fill. Run every fixture until the antifreeze is flushed out, refill the water heater completely before turning it back on, and walk the house looking for drips. A thawed-out split often doesn't show until the pressure comes back.
Landlords and property managers
We winterize vacant units and houses, check them after cold snaps, and bring them back online, with photos for your records. Property management accounts → Or call or text (720) 818-5569.