Our Process
Every HVAC contractor in west St. Louis County will tell you they “do things right.” The phrase costs nothing to say and means almost nothing in practice. What follows is the specific, measurable sequence of work that happens between your initial call and your municipal final inspection sign-off — the instruments we calibrate, the photos and meter readings we put on the work order, the calculations we run before writing a quote, and the documentation we hand you at the end. If a contractor cannot describe their process in this level of detail when asked, the process probably isn’t what they’re selling you.
Step 1: The Initial Call — Triage and Dispatch
When you call (314) 338-5111, Tess answers in person during business hours, and James personally takes the after-hours line. The initial conversation captures: nature of the issue (no-heat, no-cool, intermittent failure, planned replacement, scheduled maintenance), equipment make and model if known, equipment age, prior service history, and the urgency level (immediate emergency, same-day, scheduled). Address verification confirms you’re inside our six-city service area: Kirkwood, Affton, Sappington, Webster Groves, Crestwood, or Town and Country.
For emergency calls, dispatch follows the geographic-proximity rule: the closest available technician to the address gets the call, with James personally dispatching after 10 p.m. and on Sundays when the office is closed. For non-emergency calls, Tess schedules within a 2-hour arrival window and confirms via SMS and email 30 minutes before the technician departs.
Step 2: On-Site Diagnostic — Measurement Before Opinion
Every diagnostic visit begins with calibrated instruments on the equipment in question. The technician documents the existing condition before touching anything — thermostat setting, current indoor and outdoor temperatures, system mode, any active fault codes, and the customer’s description of the symptom timeline.
Furnace Diagnostic Sequence
- Bacharach Fyrite Insight Plus combustion analysis — CO air-free, CO2, O2, stack temperature, combustion efficiency. Target: under 100 ppm CO air-free for safe operation, stack temperature within manufacturer spec for the AFUE rating.
- Testo 510i digital manometer — gas pressure at meter (target 7" WC nominal on Spire Missouri delivery), gas pressure at manifold post-regulator (3.5" WC for natural gas single-stage burners).
- Static pressure across the air handler — supply plenum, return plenum, total external static. Target: under 0.5" WC for standard residential blowers, under 0.8" WC for ECM variable-speed.
- Hawkeye inspection borescope — visual inspection of secondary heat exchanger for cracks, carbon scoring, or condensate damage. Borescope footage saved to the work order.
- Inducer motor amperage compared to nameplate FLA on the motor label.
- Pressure switch and ignition sequence verification — verifying the safety chain operates within manufacturer specifications.
Air Conditioner Diagnostic Sequence
- Yellow Jacket TitanHV digital gauge set — suction and liquid line pressures, calculated superheat (piston-equipped systems) or subcooling (TXV-equipped systems). Target subcooling on most R-410A and R-454B systems: 7–10°F at AHRI rating conditions.
- Fluke 902 FC clamp meter — compressor inrush amperage, run amperage compared to nameplate RLA, condenser fan motor amperage.
- Capacitor microfarad reading — comparing measured value to rated value on the capacitor label. A 32 microfarad reading on a 35 microfarad rated component is within tolerance (5%); 8 microfarads on the same component is a failed capacitor.
- Contactor inspection — visual check for pitting, arc damage, and contact resistance.
- Refrigerant leak check — bubble solution on accessible joints, electronic leak detector on coils and line set if pressure indicates loss.
- Evaporator coil and condensate pan inspection — biofilm, mineral scale from 10–12 gpg Missouri American Water, secondary drain pan condition.
- FLIR ONE Pro thermal imaging — refrigerant line temperature differential, supply register temperature distribution across the home, identification of duct leakage hotspots.
Every reading goes on the work order with the instrument used and the time of measurement. Photos and thermal imaging are attached.
Step 3: Diagnosis Communication — What the Data Shows
Before any quote, the technician walks you through what the instruments measured. The capacitor reading. The static pressure number. The combustion analysis output. The borescope footage of the heat exchanger interior. The thermal imaging showing the supply register that’s running 18°F warmer than the rest of the home. This is the moment that separates an honest diagnosis from a sales pitch. If we found a $48 hot surface igniter and the previous contractor told you the heat exchanger was cracked, we’ll show you both pieces of evidence and let you draw the conclusion. We do not argue with previous contractors — we show the data.
Step 4: Written Quote — Itemized, Not Packaged
Repair Quotes
Repair quotes itemize the parts cost (with manufacturer part number where applicable), labor hours, any diagnostic fee credit if you authorize same-visit repair, and the expected timeline. Quotes are presented in writing on a printed work order. No verbal estimates, no “package pricing” that hides margin, no “we can probably make it work for around…” language.
Installation Quotes
New system installation quotes start with an ACCA Manual J load calculation. We use Wrightsoft Right-J software with the specific climate data for St. Louis Lambert (ASHRAE 99% winter design 3°F, 1% summer design 94°F dry bulb / 76°F coincident wet bulb, Climate Zone 4A) and the specific characteristics of your home: square footage by floor, ceiling heights, window U-factors and SHGC values, insulation R-values, infiltration rate, and orientation. The Manual J output gives heating and cooling design loads in BTU/hr.
Manual S equipment selection then matches AHRI-rated equipment to the calculated load. We select within 0–15% of the calculated load — never undersized, rarely oversized beyond 15%. Oversizing leads to short cycling, poor dehumidification, and reduced equipment life.
Manual D duct verification runs if existing ductwork is staying. We measure trunk and branch dimensions, calculate equivalent length including elbows and takeoffs, and verify the design friction rate (typically 0.05–0.08 inches WC per 100 feet of equivalent length) against the proposed equipment’s blower capacity.
The written installation quote itemizes: equipment cost (matched outdoor and indoor unit with model numbers), labor hours, permit fees (Kirkwood Public Works, St. Louis County Department of Public Works, or applicable municipal authority), refrigerant by pound, electrical or venting modifications, manufacturer warranty registration, and labor warranty period.
Step 5: Permit Pull and Scheduling
For installation work, Tess pulls the permit through the applicable authority within one business day of contract signing. Permit fees are billed at cost — never marked up. For Kirkwood installations, this is Kirkwood Public Works at 139 S Kirkwood Rd. For unincorporated St. Louis County (including Affton and Sappington), it’s the St. Louis County Department of Public Works at 41 S Central Ave in Clayton. Webster Groves, Crestwood, and Town and Country have their own municipal permit offices.
Installation scheduling targets the soonest practical date that accommodates equipment delivery (typically 3–7 business days for standard Carrier, Trane, Lennox, Bryant, Rheem, and Goodman residential equipment from local distributors), customer availability, and crew capacity. Emergency same-day replacements during Polar Vortex weeks or summer heatwaves can pull equipment from distributor inventory inside 4 hours.
Step 6: Installation Day — Documentation Throughout
Installation day begins with floor protection (canvas drop cloths from the entry to the work area, plastic sheeting where ductwork modification will generate debris), shoe covers on every technician, and a written walkthrough confirming the scope of work matches the signed quote. Photos document the existing condition before removal begins.
Removal of old equipment includes refrigerant recovery to EPA standards (Type II certified equipment, recovery cylinders weighed and documented), gas line shut-off and verification, electrical disconnect verification, and disposal of old equipment per St. Louis County waste regulations. Old refrigerant is sent to a licensed reclaimer with chain-of-custody documentation.
New equipment installation follows the manufacturer’s installation instruction manual to the letter — clearance dimensions, condensate drain slope, refrigerant line set sizing, electrical service requirements, and venting configuration. Photos document each major step.
Final commissioning includes refrigerant charge verification by subcooling (TXV-equipped systems) or superheat (piston-equipped systems), combustion analysis on gas-fired equipment with target under 100 ppm CO air-free, static pressure measurement on the new system, and verification of all safety controls. Commissioning results go on the work order.
Step 7: Inspection and Walkthrough
The municipal inspector visits within 5–10 business days of installation completion (timing depends on the inspector’s schedule at Kirkwood Public Works, St. Louis County, Webster Groves, Crestwood, or Town and Country). We coordinate the inspection time with you and meet the inspector on site if requested.
After the inspector’s sign-off, we conduct a final customer walkthrough: how the new thermostat operates, where the filter is and what MERV rating to maintain, the recommended filter change interval, the location of the emergency gas shutoff and electrical disconnect, the spring and fall maintenance schedule, and the customer’s manufacturer warranty paperwork and Purisync labor warranty card.
Step 8: Warranty Registration and Follow-Up
Tess submits manufacturer warranty registration within the 60-day window required by Carrier, Trane, Lennox, Bryant, Rheem, Goodman, Mitsubishi, Daikin, and Bosch for residential equipment. The registration confirmation email is forwarded to you for your records.
A 30-day follow-up call from Tess confirms the system is performing as expected, addresses any questions about thermostat programming or maintenance scheduling, and adds you to our spring and fall maintenance reminder list. The reminder list is opt-in — we don’t subscribe customers to marketing email without explicit consent.
What the Process Excludes
Several things are explicitly not part of how we work:
- Same-day pressure to make a decision. No quote is presented with a “this price is only good if you sign today” clause.
- Verbal estimates or unwritten “approximately around” quotes. Everything is in writing.
- Sales commissions for technicians. Our technicians are paid hourly — not on revenue, not on equipment sold, not on package upgrades. The motivation to recommend a $9,000 replacement over a $200 repair does not exist on our payroll structure.
- Replacement-sales theater on functional equipment. A 14-year-old Lennox passing combustion analysis under 100 ppm CO air-free, with no heat exchanger cracks visible under borescope, gets a clean inspection report and a maintenance recommendation.
- Subcontracted work. The technician who shows up at your house is a Purisync employee, on payroll, NATE-certified or apprenticing toward it, EPA Section 608 Universal certified, and accountable directly to James.
Frequently Asked Questions
- What instruments do Purisync technicians use during a diagnostic visit?
- Bacharach Fyrite Insight Plus combustion analyzer for furnace diagnostics, Testo 510i digital manometer for gas pressure and static pressure measurement, Yellow Jacket TitanHV digital gauge set for refrigerant pressures and superheat/subcooling, Fluke 902 FC clamp meter for compressor and motor amperage, Hawkeye inspection borescope for heat exchanger and evaporator coil inspection, and FLIR ONE Pro thermal imaging camera for duct leakage and refrigerant line surveys. Every reading and image goes on the work order.
- How does Purisync size a new HVAC system?
- ACCA Manual J load calculation using Wrightsoft Right-J software with St. Louis Lambert climate data (Climate Zone 4A, ASHRAE 99% winter design 3°F, 1% summer design 94°F dry bulb with 76°F coincident wet bulb). The Manual J output gives heating and cooling design loads in BTU/hr. Manual S equipment selection matches AHRI-rated equipment within 0–15% of the calculated load. Manual D duct verification confirms existing ductwork can handle the new equipment’s blower capacity at design friction rate 0.05–0.08 inches WC per 100 feet of equivalent length.
- What happens during installation day?
- Floor protection and walkthrough first, then removal of old equipment (refrigerant recovered to EPA standards, equipment disposed per St. Louis County waste regulations), new equipment installation following the manufacturer’s installation manual, and commissioning. Commissioning includes refrigerant charge by subcooling or superheat, combustion analysis under 100 ppm CO air-free on gas equipment, static pressure measurement under 0.5\” WC, and safety control verification. Photos document each step. Results go on the work order.
- Who handles the permit and inspection?
- Tess pulls the permit through the applicable authority (Kirkwood Public Works, St. Louis County Department of Public Works for Affton and Sappington, Webster Groves Public Works, Crestwood Public Works, or Town and Country Public Works) within one business day of contract signing. The municipal inspector visits within 5–10 business days of installation completion. We coordinate the inspection time with you and meet the inspector on site if requested.
- Do technicians get paid commission on equipment they sell?
- No. Purisync technicians are paid hourly. There are no sales commissions, no per-system bonuses, and no incentive payments tied to equipment recommendations. The motivation to recommend a $9,000 replacement over a $200 repair does not exist on our payroll structure. This is intentional — it’s the single most important structural protection against replacement-sales theater, and it’s why a 14-year-old Lennox passing combustion analysis gets a clean inspection report rather than a system pitch.
Contact Purisync Heating and Air
If you want to see the process in action — the instruments, the work order documentation, the Manual J output — schedule a diagnostic visit. The technician will walk you through every measurement before any quote is written. Tess can answer scheduling questions during business hours, and James personally handles the after-hours emergency line.
- Emergency Line (24/7): (314) 338-5111
- Address: 325 N Kirkwood Rd #245, Kirkwood, MO 63122
- Email: info@purisyncheatingairconditioning.xyz
- St. Louis County Mechanical Contractor License: #MC-2014-08439-STL
- Kirkwood Business Registration: #BL-2014-1187
- EPA Section 608 Universal: #608U-2014-385721
Office Hours
- Emergency Service: 24 hours a day, 7 days a week
- Office Staff: Monday – Saturday, 9:00 AM – 5:00 PM
- Closed: Sundays and State/Federal Holidays (emergency line always active)