Well winter freeze checklist: the pitless adapter, the pressure tank, the hydrant and where heat tape does not belong
A well freeze checklist: Minnesota code buries supply pipe 12 inches below the local frost depth, and a pitless adapter attaches 6 or 7 feet down.
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Short answer
A well freeze checklist starts underground and works upward, and the buried half is usually already solved. Minnesota’s plumbing code, Minn. R. 4714.0609, requires building supply and yard piping to be located not less than 12 inches below the maximum local frost depth, with cover not less than 12 inches below finish grade. The code never names a frost depth, because that number is local: the National Weather Service measures it with an NWS/HAHN frost gauge. The Minnesota Department of Health says a pitless adapter attaches to the casing usually 6 or 7 feet down, and the service pipe runs deeper than the frost line, so the water will not freeze. What freezes is everything above grade. Amtrol says not to operate a Well-X-Trol tank in freezing temperatures, Goulds says to select a site where the pump and tank will not freeze, and Woodford warns its Model 14 wall faucet may freeze and burst if the hose stays attached.
The picks
A well house that has power and a dry mounting spot
TPI RPH15A Pump House Convection Heater
TPI lists the RPH15A as a pump house convection specialty heater, 500 W, 4.2 amps
Running that heater only when the space is near freezing
HEATIT ET-21 Freeze Protection Thermostat Outlet
HEATIT states on at 38 F and off at approximately 50 F, maximum 15 amps at 120 VAC, CSA approved, dry locations only
Exposed pump-to-tank pipe and above-ground discharge
K-FLEX USA Elastomeric Pipe Insulation, 3/4 in x 6 ft
3/4 inch elastomeric pipe insulation in 6 foot lengths; EasyHeat separately calls for 1/2 inch fiberglass with a vapor seal over its cable
An above-ground backflow assembly or hydrant head, as a wind break only
Cholila Insulated Backflow Preventer Cover, 30 x 24 in
Insulated cover, 30 inches wide by 24 inches high; a cover holds heat that is already there and makes none
A freeze alarm at a seasonal property with no Wi-Fi
Frigga 4G Cellular Temperature and Humidity Monitor
4G cellular monitor with email and app alerts, so it reports without a local network or router
A well house inside range of the house Wi-Fi
GoveeLife Wi-Fi Thermometer Sensor with Alarm and Gateway
Wi-Fi sensor with alarm, supplied with the gateway; needs a working router and power at the property
If the pipe that split is inside the house, this is the wrong page: interior plumbing and heat cable sizing are the house side of freeze protection.
How deep does the buried pipework need to be?
Deeper than the frost line, and the frost line is local. Minn. R. 4714.0609, section 609.1, puts building supply and yard piping not less than 12 inches below the maximum local frost depth, with cover not less than 12 inches below finish grade, and never names a depth itself.
The National Weather Service reads frost depth as an observation, not a constant: cooperative sites read an NWS/HAHN frost gauge, some daily and some a few days per week, and NWS notes that snow insulates, so uninsulated surfaces can show deeper frost in a hard cold snap.
A correctly installed pitless adapter already puts the horizontal run at that depth. The Minnesota Department of Health says pitless adapters and units attach to the casing below ground, usually 6 or 7 feet down, and that because the service pipe is buried deeper than the frost line the water will not freeze. The Water Systems Council names WSC PAS-97 (2019)(R2023) as the industry standard.
So the pitless adapter is not a winter task. It is the reason there is no winter task down there.
What keeps a well house, or an old well pit, out of trouble?
Minn. R. 4725.2250 requires a casing or casing extension to extend vertically at least 12 inches above the established ground surface, the floor of a well house, or a concrete slab, with the adjacent surface graded to divert water away. Terminating the casing below grade, in a well pit, is prohibited.
MDH is blunt about why pits existed: wells were completed below ground level so the pump and water pipes would not freeze. Current rules prohibit new pits, and MDH recommends extending the casing above ground, fitting a pitless unit or adapter, and filling the pit with clean earth.
For a well house that is staying, the job is heat, not insulation alone. A TPI RPH15A is listed by TPI as a pump house convection heater at 500 W and 4.2 amps, and a thermostat outlet such as the HEATIT ET-21 runs it only near freezing: HEATIT states on at 38 F, off at approximately 50 F, maximum 15 amps at 120 VAC, CSA approved, dry locations only.
Which above-ground parts freeze first?
| Part | What the maker says | What that means in winter |
|---|---|---|
| Pressure tank | Amtrol: do not operate in a setting with freezing temperatures or where temperature can exceed 130 degrees F | Heat the room, do not wrap the tank |
| Pump and pressure switch | Goulds: select a site where the pump and tank will not freeze; pump within 4 feet of the tank to prevent switch chatter | A tank moved to a warmer corner can pull the pump out of spec |
| Underground pressure tank | Amtrol: buried below the frost line and above the water table, factory precharge 38 psig | Depth is the protection; nothing to check at the surface |
| Exposed discharge and drop pipe | EasyHeat calls for 1/2 inch fiberglass pipe insulation with a vapor seal over its cable | Insulate the run; insulation alone only slows the loss |
| Hose bib | Woodford Model 14: install with downward pitch toward the nozzle, remove the hose in freezing weather or it may freeze and burst | The hose is the failure, not the faucet |
| Yard hydrant | Woodford: drain hole below the frost line, pit bottom filled with 1/2 inch gravel to at least 3 inches above the brass drain valve body | If it does not drain, it freezes |
Amtrol sets the tank precharge 2 psig below the pressure switch cut-in, 38 psig for a 40/60 switch, and only at ambient temperature: a cold morning is the wrong time to chase a reading. Woodford warns that saturated ground in the hydrant drain field can prevent the hydrant from draining fully and may result in freezing, so a low or wet spot needs a larger drain field.
Before you buy a heater or a cover
Do not order anything until you know which part is actually cold. An insulated cover such as the Cholila backflow preventer cover holds heat that is already there and makes none, so on an unheated hydrant head it buys hours, not a season. A logging sensor is worth more than a 500 W heater bought on a guess.
Where does heat tape belong, and where is it a fire risk?
On the pipes the maker rates, and nowhere else.
CPSC estimates that about 1,500 fires, 10 deaths and 100 injuries a year result from faulty electric heat tapes, and advises replacing uncertified tapes more than 3 years old with tapes certified to UL, CSA or FMRC standards. It also says not to wrap heat tape over itself, or cover it with insulation, unless the maker permits it, and to use non-flammable fiberglass rather than foam or vinyl.
EasyHeat’s Freeze Free sheet shows how narrow a rating gets.
| EasyHeat Freeze Free says | Detail |
|---|---|
| Use only on | Metal and plastic domestic water pipes: PVC, PEX or polybutylene |
| Never use on | Flexible vinyl tubing such as garden hose, buried pipes, pipes carrying anything but water, roof, gutter or driveway de-icing |
| Maximum circuit length | 75 feet |
| Required protection | A ground fault protection device, because fault currents from damaged cable may not trip a conventional breaker |
| Do not install below | -20 degrees F (-29 C) |
| Over the cable | 1/2 inch fiberglass pipe insulation with a vapor seal |
Nothing in that covers a buried service line, a casing or a tank shell.
Drain down, or keep it heated, at a seasonal property?
The Water Systems Council’s winterizing sheet drains it, and the order matters.
| # | Closing up (WSC) | Why |
|---|---|---|
| 1 | Shut the house supply at the main shut-off valve | Everything downstream can then be emptied |
| 2 | Turn the well pump breaker OFF, leave the main breaker ON | So nobody restarting the main triggers the pump |
| 3 | Open every tap until water no longer flows | Gravity does most of the work |
| 4 | Give each faucet a low pressure blast of compressed air | Clears what gravity left |
| 5 | Pour non-toxic propylene glycol RV antifreeze into the traps | At least a quart per lavatory, sink and tub trap, about a gallon per toilet tank |
The pump itself may need nothing. WSC says a pump in a deep well you cannot access requires no further action, because the depth of the well prevents it from freezing. A shallow well jet pump is the opposite: loosen the hose clamps on the feed and pump lines and drain it per the maker’s instructions. Goulds says vertical pumps have one drain plug on the casing, horizontal pumps may have two, and multi-stage pumps may need compressed air blown into one hole.
Reopening is staged: repair known breaks, close every faucet, open the main, then open zone shut-offs one at a time and test each fixture with about a quart of water. An above-ground pump may need priming and must never run dry. A sample belongs in there too: see the well water test panel guide, and what to do first at a flooded well if snowmelt reached the casing.
What should you do first?
- Get your local frost depth from the county or state code, not a national map.
- Walk the wellhead: casing 12 inches above grade or the well house floor, cap intact, ground graded away (Minn. R. 4725.2250).
- Take every hose off every bib, and open and close the yard hydrant to confirm it drains.
- Log the well house temperature for a week before buying a heater.
- Decide drain-down or keep-heated now, and book the contractor WSC recommends.
Frequently asked questions
How deep does a well water line have to be buried to stay unfrozen?
Minnesota's plumbing code, at Minn. R. 4714.0609 section 609.1, requires building supply and yard piping to sit not less than 12 inches below the maximum local frost depth, with cover not less than 12 inches below finish grade. The code deliberately points at the local frost depth rather than naming one, because that number varies by county and by winter.
Does a pitless adapter need anything done to it before winter?
Not underground. The Water Systems Council says the pitless adapter connects to the casing below the frost line and diverts water horizontally to keep it from freezing, and names WSC PAS-97 (2019)(R2023) as the industry standard. What is worth checking above grade is the casing, the cap and the grading, which Minnesota requires to divert water away.
Can a pressure tank freeze?
Amtrol's Well-X-Trol instructions tell owners not to operate the tank in a setting with freezing temperatures, or where temperature can exceed 130 degrees F. Goulds says to select a site where the pump and tank will not freeze, and to keep the pump within 4 feet of the tank to prevent switch chatter. Heat the space rather than wrapping the tank.
Is heat tape safe to leave on a well line all winter?
CPSC estimates about 1,500 fires, 10 deaths and 100 injuries a year from faulty electric heat tapes, and advises replacing uncertified tapes more than 3 years old with tapes certified to UL, CSA or FMRC. EasyHeat's Freeze Free cable is rated only for metal and plastic domestic water pipes and states never to use it on buried pipes.
Should a seasonal cabin's well be drained or kept heated?
The Water Systems Council's winterizing sheet drains it: shut the main valve, turn the well pump breaker off while leaving the main breaker on, open every tap until flow stops, then blow the lines out with a low-pressure blast of air. It adds that a submersible pump in a deep well needs no further action, because the depth prevents freezing.
Fact sheet and how to cite this page
- Answer
- Minnesota’s plumbing code puts building supply and yard piping not less than 12 inches below the maximum local frost depth, with cover not less than 12 inches below finish grade, and never states a frost depth itself. A pitless adapter attaches to the casing usually 6 or 7 feet down, so the buried half is already handled and the freeze risk is above grade.
- Basis
- Minn. R. 4714.0609 section 609.1 for the burial depth, Minn. R. 4725.2250 for casing height and the well pit prohibition, and the Minnesota Department of Health Well Owner’s Handbook for pitless adapter depth.
- Assumptions
- A private well with a pitless adapter or pitless unit, a pressure tank indoors or in a well house, and above-ground discharge, hose bibs or a yard hydrant.
- Frost depth is a local, observed number. The National Weather Service measures it with an NWS/HAHN frost gauge, and snow cover changes the reading.
- Interior house plumbing, frozen pipe claims and heat cable sizing are the house side of freeze protection and are not covered here.
- Method
- Code and depth figures read from the Minnesota Revisor of Statutes and the Minnesota Department of Health handbook; equipment limits read from the Goulds IM102, Amtrol Well-X-Trol, Woodford and EasyHeat documents; heat tape fire figures from CPSC. All read on 21 September 2026.
- Primary source
- Minnesota Rules 4714.0609, Installation, testing, unions, and location (government or regulatory source)
- Facts verified
- Last updated
- Cite as
- OwnerSpec, "Well winter freeze checklist: the pitless adapter, the pressure tank, the hydrant and where heat tape does not belong", https://ownerspec.com/water/guides/well-winter-freeze-checklist/, facts verified 21 September 2026.
Every figure above also appears, with its source, in the article. All sources ยท How OwnerSpec verifies numbers
Sources
- Minnesota Rules 4714.0609, Installation, testing, unions, and location (government or regulatory source)
- Minnesota Rules 4725.2250, Well casing and casing extension (government or regulatory source)
- Minnesota Department of Health, Well Owner's Handbook (PDF) (government or regulatory source)
- Water Systems Council, wellcare information sheet: Your Pitless Adapter (PDF) (manufacturer or vendor document)
- Water Systems Council, wellcare information sheet: Winterizing and De-winterizing Your Well (PDF) (manufacturer or vendor document)
- Goulds Water Technology, Jet Pumps instruction manual IM102 (PDF) (manufacturer or vendor document)
- Amtrol, Well-X-Trol Residential Pre-Pressurized Well Tanks installation and operation instructions (PDF) (manufacturer or vendor document)
- Woodford Manufacturing, Yard Hydrant Installation Instructions (PDF) (manufacturer or vendor document)
- Woodford Manufacturing, Freezeless Wall Faucet Model 14 catalog sheet (PDF) (manufacturer or vendor document)
- CPSC, CPSC Re-Issues Heat Tape Guidelines In Wake Of Zoo Fire (1996) (government or regulatory source)
- EasyHeat, Freeze Free Self Regulating Pipe Heating System instruction sheet (PDF) (manufacturer or vendor document)
- National Weather Service Buffalo, Frost Depth Observations (government or regulatory source)
- HEATIT, ET-21 Freeze Thermostatically Controlled Outlet product page (manufacturer or vendor document)