The Ten Red Flags That Expose a Bad Snow-Melt Install
Each flag below is a question to ask your provider directly. One flag is a caution; two or more means walk away and call a matched provider instead.
| # | Red Flag | Why It Dooms the System | What to Ask Instead |
|---|---|---|---|
| 1 | Vague testing protocol — "we checked it with a multimeter" | Only a 500 VDC Megohmmeter (Megger) detects insulation breaches; a multimeter cannot see them | "May I see your Megger log with the three-stage results?" |
| 2 | No cold-water flush plan (asphalt projects) | Asphalt is poured at 300°F+; without the flush, the tubing softens and deforms | "Walk me through your cold-flush procedure and the 150°F return limit." |
| 3 | Missing insulation — "skip the foam to save costs" | Over 50% of the heat bleeds into the frozen earth; operating costs roughly double | "What R-value are you specifying under the slab — and why?" |
| 4 | Shared conduit — power and sensor leads in one raceway | Electrical interference corrupts the sensor signal; the system fires or fails at the wrong moments | "Are the cold leads and sensor cables in completely separate conduits?" |
| 5 | No documentation — no as-built maps or layout photos | Future repairs become blind drilling and cutting into a buried system | "Will you provide as-built layout maps and photos before the pour?" |
| 6 | No Snow-Free Area Ratio conversation | The Ar drives the heat-flux and the sizing; quoting per square foot without it is guesswork | "What Ar are you designing for, and what does that guarantee?" |
| 7 | Standard 100-amp service assumption | Most systems need 200–400 amp service — a $2,000–$4,000 hidden cost | "Have you confirmed the service capacity with the utility?" |
| 8 | No megohm test during the pour | Testing is mandatory at three stages; skipping the mid-pour test buries damage | "Can I watch the three-stage test sequence?" |
| 9 | Oversized loops or unbalanced manifolds | Loops over 300 ft (1/2" PEX) or manifolds off by more than 10–15% create cold spots | "What are the loop lengths and the manifold balance?" |
| 10 | No edge insulation | Lateral heat migration into adjacent soil defeats the thermal envelope | "Is edge insulation part of the spec?" |
The bottom line: these ten questions take ten minutes. A provider who answers them cleanly is engineering a system; one who waves them off is selling components. The 50-question master guide in our blog covers the full procurement protocol.