Methodology

How the quote-first comparison works

Seven active calculators use versioned decision policies for US users in en-US and USD. Their thresholds explain a comparison; they are not universal facts, professional diagnoses, or guarantees.

Effective date: July 23, 2026
Last updated: July 23, 2026

1. Safety overrides economics

Immediate electrical, gas, combustion, refrigerant, pressure, leak, heat, fire, or other category-specific hazards stop the price comparison. The result directs the user away from hazardous DIY work and toward an appropriate qualified professional or emergency service.

2. Warranty comes before out-of-pocket cost

Possible or confirmed coverage can return a warranty-first result. Exact coverage must be verified for the specific product with the manufacturer, installer, home-warranty provider, or authorized servicer.

3. Actual quotes take precedence

The calculators use the written repair quote and replacement price or installed quote entered by the user. Required delivery, installation, removal, permits, hookups, matching, and trade scope remain explicit. No private cost draft or generic market estimate is substituted.

4. A versioned policy sets the comparison ceiling

Age, recent failures, quote completeness, prior major repair, and category-specific details can adjust the maximum sensible repair quote. A close-decision margin avoids false precision. These thresholds are decision policy, not a claim about every appliance or local market.

5. Uncertainty stays visible

Confidence, missing information, important factors, possible decision changes, model version, and disclaimers remain visible. “I don't know” is accepted for technical questions. Optional brand, model, and error code are context only and never confirm a fault.

Privacy and indexing

Answers and results exist only in current-tab memory. No result URL is created, and no raw input is written to accounts, cookies, local storage, databases, server logs, cache keys, or analytics. Coarse events contain only workflow stage and a broad result class.

Active model versions

Washing Machine 0.2.0 · Dryer 0.1.0 · Refrigerator 0.1.0 · Dishwasher 0.1.0 · Range & Oven 0.1.0 · Water Heater 0.1.0 · Central Air Conditioner 0.1.0. Model changes require the project's separate review and activation controls; this public presentation does not recalibrate them.

Active calculator configurations last reviewed: July 19, 2026. Read the source boundaries.