Top 5 Mistakes Builders Make When Electrifying Hot Water Systems (And How to Avoid Them)

May 6, 2025

⚠️ Electrification Is Inevitable. Mistakes Don’t Have to Be.

As more cities and states ban natural gas in new construction, builders are pivoting hard toward all-electric mechanical systems.

But there’s one area consistently causing cost overruns, customer complaints, and compliance issues:
Domestic hot water.

While heat pumps and high-efficiency electric heaters promise lower emissions and better performance, they introduce a range of complications when installed without the right planning.

At Solthera, we’ve worked with builders across California and beyond. Here are the top five mistakes we see—plus how to avoid them.

1. Oversizing Heat Pumps to “Fix” Undersized Water Systems

The mistake:
To ensure enough hot water, some builders oversize the HVAC system to “compensate” for a slow or underperforming water heater.

Why it's bad:

  • It drives up cost, energy use, and system complexity
  • Oversized systems short-cycle and wear out faster
  • It still doesn’t solve the peak load issue

The fix: Add a thermal battery like Solthera to store hot water energy during low-use hours. That way, your heat pump can stay right-sized—and still deliver instant hot water.

2. Assuming Tankless Equals Maintenance-Free

The mistake:
Builders often default to electric tankless water heaters, assuming they’re “set it and forget it” solutions.

The reality:

  • They require major electric service (often 200A+)
  • They spike loads during simultaneous use (showers + laundry)
  • They can’t store any energy or preheat during off-peak hours

The fix: Use Solthera to decouple energy generation from energy use. This reduces stress on both panel load and utility costs.

3. Ignoring Code-Specific Grid Impact (Title 24, TDV, etc.)

The mistake:
Builders meet baseline performance, but don’t optimize for time-dependent valuation (TDV) or grid harmonization, especially under Title 24 or LEED guidelines.

The consequence:

  • Missed compliance points
  • Lower performance scores
  • Rejected plans or retrofit redesigns

The fix: Solthera can store heat during low-TDV hours and deliver it during peak demand—automatically. That earns smart control points and unlocks performance-based incentives.

4. Overcomplicating Mechanical Design

The mistake:
Trying to Frankenstein together tankless units, hybrid HPWHs, backup resistive elements, and smart controllers to “solve” hot water needs.

Result:

  • Multiple failure points
  • Confused installers and unhappy inspectors
  • Systems that don’t scale across unit types

The fix: Solthera simplifies the system. It’s a single unit with zero moving parts, compact design, and plug-and-play integration into hydronic loops or domestic hot water plumbing.

5. Forgetting the Customer Experience

The mistake:
Assuming that code compliance equals occupant satisfaction.

But what do homeowners want?

  • Fast hot water
  • Quiet operation
  • Long-term reliability
  • Lower bills

The fix: Solthera delivers hot water on demand with no standby loss, no mechanical noise, and a 20+ year life expectancy.

🔋 Solthera = Smarter Electrification

Solthera is not a tank, a heater, or a gimmick. It’s a thermal battery engineered to store energy and release it when you need it most—without requiring oversized electrical infrastructure or complex mechanical design.

By integrating Solthera early in your project, you’ll:

  • Hit code and performance targets
  • Avoid load calculation nightmares
  • Improve owner satisfaction
  • Reduce long-term O&M risks