Pool Temperature Guide for Colorado Winters

A Guide from Sunshine Construction

As your trusted pool builder in the Denver area, we understand that protecting your investment during Colorado’s harsh winters is a top priority. This guide will help you understand the optimal temperature settings for your pool throughout the year, especially during winter and when you’re away from home.

Understanding Your Pool’s Winter Needs

Your Coverstar automatic pool cover is an excellent first line of defense for your pool, but maintaining the right water temperature is equally crucial for protecting your pool structure, equipment, and water chemistry.

Recommended Temperature Settings

Winter Swimming: For Active Pool Users

Comfortable Swimming Range: 78-84°F

Many of our Colorado customers love using their pools year-round, and with proper heating and your Coverstar cover, this is absolutely possible:

• Recreational Swimming: Most people find 78-80°F comfortable for casual swimming and exercise
• Therapy/Relaxation: 82-84°F feels more spa-like and is ideal for hydrotherapy or just relaxing
• Children and Seniors: Often prefer the warmer end of this range (82-84°F)

Example Heating Costs: Maintaining a swimming temperature of 78-84°F during Denver winters requires significantly more heating than summer months:

• December-February: Expect heating costs to be 2x-3x higher than your typical summer months
• November and March: Typically 1.5x-2.5x higher than summer as shoulder seasons
• Your Coverstar cover is absolutely essential at these temperatures – without it, costs could easily be 600-800% higher than summer

High-Temperature Preference: 85-92°F

Some customers prefer spa-like temperatures for therapeutic purposes or simply because they enjoy warmer water:

• 85-88°F: Very warm, great for therapy, less ideal for exercise
• 88-92°F: Hot tub territory, excellent for muscle relaxation and therapeutic use

Example Heating Costs: These temperatures come with premium heating bills:

• Expect heating costs to be 3x-6x higher than summer months during peak winter
• These temperatures require excellent insulation and your Coverstar cover must remain closed when not in use

Winter Maintenance Mode: For Non-Swimming Season

Ideal Range: 50-60°F

If you’re not planning to swim during winter, this range offers the best balance of protection and economy:

• Prevents Freezing: Water at 50-60°F stays well above the freezing point, protecting your pool shell, plumbing, and equipment from freeze damage
• Maintains Chemistry: Water chemistry remains more stable in this temperature range
• Equipment Protection: Your pump, filter, and heater components are protected from freeze damage
• Cost Effective: This temperature range balances protection with reasonable heating costs

Example Heating Costs: Maintenance mode is much more economical:

• Typically 50-100% higher than summer heating costs
• Much more affordable than swimming temperatures while still providing complete freeze protection

When You’re Leaving Town (Short Term: 1-2 Weeks)

If You’ve Been Swimming (Pool at 78°F+):

• You can lower to 70-75°F for short trips to save costs
• Or maintain your preferred swimming temperature if you want to jump right back in
• Lowering by 8-10°F can reduce heating costs by approximately 20-30% during your absence

If You’re in Maintenance Mode (Pool at 50-60°F):

• Maintain 50-55°F
• Ensure your Coverstar cover remains closed
• Have a neighbor or pool service check mid-trip if possible
• Costs remain consistent with normal winter maintenance mode

When You’re Leaving Town (Extended: 1+ Months)

Recommended: Lower to Maintenance Mode (45-55°F)

Even if you typically swim year-round, we recommend lowering the temperature during extended absences:

• Minimum Temperature: Never below 45°F, even if you’re gone all winter
• Sweet Spot: 50-55°F provides excellent protection at moderate cost
• Monitoring: Essential to have someone check weekly or use remote monitoring

Cost Savings:

• Lowering from swimming temperature (78°F+) to maintenance mode (50-55°F) can reduce your heating costs by 60-75% during your absence
• This is one of the most significant savings you can achieve while still maintaining complete freeze protection

The Hidden Cost of Temperature Cycling: Why Constant Setbacks Can Cost You More

Many pool owners think they can save money by frequently lowering their pool temperature and then reheating it when they want to swim. However, this strategy often backfires and can actually increase your total heating costs rather than reduce them.

Why Reheating Is So Expensive

The Physics of Heat Loss: When you lower your pool temperature significantly (for example, from 80°F down to 60°F), you’re allowing the entire body of water to cool down. Reheating that massive volume of water back to swimming temperature requires an enormous amount of energy – often more than you saved by the temporary setback.

The Math Doesn’t Work:

• A typical 20×40 pool holds approximately 20,000-30,000 gallons of water
• Every degree of temperature change requires heating or cooling thousands of gallons
• Reheating from 60°F to 80°F (a 20-degree increase) can take 24-48 hours of continuous heating
• During this reheat period, your heater runs at maximum capacity continuously, consuming gas at the highest possible rate

Real-World Example

Let’s say you lower your pool from 80°F to 60°F for a week to “save money”:

What You Might Save: Running at 60°F for a week might save you 30-40% compared to maintaining 80°F

What It Costs to Reheat: Bringing the pool back up 20 degrees requires your heater to run continuously for 1-2 days, often consuming more energy than you saved during the entire week of lower temperature – especially if you’re reheating during cold weather

The Bottom Line: If you cycle your pool temperature down and back up more than once or twice per month, you’re likely spending 10-30% more on heating than if you had just maintained a consistent temperature.

When Temperature Setbacks Make Sense

Temperature setbacks can save money, but only in specific situations:

✓ Good Scenarios for Lowering Temperature:

• Extended absences (3+ weeks): Long enough that savings outweigh reheat costs
• End of season: Transitioning from swimming season to winter maintenance mode (and staying there)
• Rare use: If you only swim 1-2 times per month, keeping it cool between uses may be worth it

✗ Bad Scenarios for Temperature Cycling:

• Weekend swimming only: Lowering Monday-Thursday and reheating Friday wastes money
• Frequent setbacks: Cycling up and down multiple times per month
• Small temperature changes: Lowering by just 5-10°F and reheating provides minimal savings but still costs energy
• During extreme cold: Reheating during sub-zero weather is extremely expensive

Our Recommendation: Pick a Temperature and Stick With It

For Active Winter Swimmers: Maintain your preferred swimming temperature (78-84°F) consistently throughout the season. The cost of maintaining this temperature is less expensive than repeatedly cycling the temperature up and down.

For Occasional Winter Swimmers: Keep your pool at a moderate temperature (68-72°F) that’s easier to boost up for swim days. This “compromise temperature” allows quicker, less expensive warming when needed.

For Non-Swimmers: Set to maintenance mode (50-60°F) and leave it there all winter. Don’t try to save a few extra dollars by going lower – the risk and reheat cost aren’t worth it.

The Exception: Smart Overnight Setbacks

There is one type of setback that does save money: modest overnight temperature reductions when you’re swimming daily:

• Lower your pool by 5-8°F each night (for example, from 82°F to 75°F)
• Reheat in the morning back to swimming temperature
• This typically saves 15-25% on heating costs
• Works because: the setback is small (less water to reheat), predictable (happens every day), and the reheat time is manageable (4-6 hours instead of 24-48 hours)

Remember: Your Heater Works Hardest During Reheating

When your heater is working to raise the temperature, it’s running continuously at maximum output. During maintenance mode (holding a steady temperature), your heater cycles on and off as needed, often running at lower capacity. Counterintuitively, steady state heating is almost always more efficient than recovery heating.

Think of it like your car: Highway driving at constant speed is more fuel-efficient than constant acceleration from stop signs. Your pool heater works the same way – steady maintenance is more efficient than dramatic temperature recovery.

Cost Comparison: Swimming vs. Protection Mode

Understanding the cost differences helps you make informed decisions:

Actual costs depend on pool size, outdoor temperatures, cover quality, insulation, and gas rates

Why Never Turn the Heater Off Completely in Winter

Regardless of your preferred swimming temperature, never shut down heating entirely in Colorado:

The Risks:

• Freeze Damage: Even one night of subfreezing temperatures can crack your pool shell, burst pipes, or damage equipment. Repairs can easily cost $5,000-15,000 or more.
• Surface Damage: Freezing water expands, which can pop tiles, crack plaster or vinyl liners, and damage coping
• Equipment Failure: Frozen pumps, filters, and heaters may need complete replacement ($2,000-8,000)
• Plumbing Disasters: Burst underground plumbing lines require excavation and repair ($3,000-10,000+)

The Bottom Line: Even with winter heating costs 50-100% higher than summer (maintenance mode), this is dramatically less expensive than a single freeze-related repair incident that could cost $10,000 or more. A full winter of maintenance heating might cost you the equivalent of 3-4 extra summer months, but one freeze event could cost more than years of heating bills.

Cost-Saving Tips for All Temperature Ranges

1. Keep Your Cover Closed: This single action can reduce heating costs by 40-60% – it’s your most powerful cost-saving tool
2. Pick a Temperature and Maintain It: Avoid frequent cycling – consistency is almost always cheaper than setbacks and reheating
3. Use Smart Overnight Setbacks Only: If swimming daily, lower by 5-8°F overnight and reheat in the morning – can save 15-25% on heating costs
4. Regular Maintenance: Clean filters, properly calibrated thermostats, and well-maintained heaters run more efficiently – can improve efficiency by 10-15%

When to Call Sunshine Construction

Contact us immediately if:

• Your pool temperature drops below 45°F
• Heating costs seem unusually high (significantly more than the percentages mentioned)
• You’re considering upgrading to year-round swimming and need equipment assessment
• Your Coverstar cover isn’t operating properly
• You notice equipment malfunctions or unusual noises
• You want a custom winter plan based on your specific usage and budget
• Your heater is struggling to maintain temperature

Final Recommendations

For Year-Round Swimmers:

• Active Use: 78-84°F (expect costs 2x-3x higher than summer)
• Maintain this temperature consistently – don’t cycle up and down
• Cover closed when not swimming
• Weekly chemistry checks
• Professional equipment inspection before winter

For Seasonal Swimmers:

• Maintenance Mode: 50-60°F (expect costs 50-100% higher than summer)
• Cover closed at all times
• Monthly chemistry checks
• If you want occasional winter swims, consider keeping at 68-72°F for easier warm-up

For Everyone:

• Never go below 45°F – one freeze event can cost more than multiple winters of heating
• Pick your temperature and stick with it – temperature cycling usually costs more money
• Keep your Coverstar cover closed – this alone saves 40-60% on heating
• Monitor weekly, either in person or via automation
• Plan your heating budget before winter arrives
• Remember: higher winter costs are normal and necessary for protection

Sunshine Construction has been building and maintaining pools in the Denver area for years. We understand Colorado’s unique climate challenges and are here to help protect your investment year-round, whether you’re swimming in January or just keeping your pool safe until spring. For questions about your specific pool or heating system, fill out an inquiry on our website