Furnace Installation Older Home — Magna, UT Case Study

A Magna customer in a 1925-built original townsite home contacted us about heating system replacement. Their home had operated on a hot-water boiler system with cast-iron radiators since original construction — over 100 years of heating history with multiple boiler replacements over the decades. The current boiler was 22 years old and reaching end of service life with increasing repair needs. The customer was considering whether to replace the boiler with another hot-water system or convert to forced-air heating with central AC capability. This case study documents the assessment process, the decision to maintain the hydronic system with modern equipment, and the boiler replacement project.

Customer Situation

• Home: 1925-built Magna townsite home, original construction, approximately 1,420 sq ft
• Existing system: 22-year-old atmospheric-vent cast-iron sectional boiler, original cast-iron radiator distribution, original chimney venting
• Existing AC: None — home operated on window units for summer cooling
• Symptom: Increasing boiler repair needs; lower efficiency than modern equipment; customer considering future direction
• Customer priorities: Reliable long-term heating system; consider AC addition; preserve home character; reasonable budget

Boiler vs. Forced-Air Conversion Discussion

We provided honest analysis of both options:

Option A: Modern boiler replacement (preserving hydronic system)

Advantages:
– Preserves existing cast-iron radiator distribution — quiet, comfortable, no air drying
– No ductwork installation required (no demolition or rebuilding interior spaces)
– Modern modulating condensing boilers efficient and reliable
– Customer accustomed to hot-water heating comfort characteristics
– Faster installation, less invasive

Disadvantages:
– No cooling capability through hydronic distribution
– AC addition would require separate system (mini-split, etc.)
– Higher equipment cost than forced-air furnace
– Slightly more complex maintenance than forced-air

Project pricing for modern boiler replacement: $11,500–$15,000 depending on equipment tier

Option B: Boiler-to-forced-air conversion

Advantages:
– Forced-air provides both heating and cooling distribution
– Lower equipment costs (furnace + AC vs. premium boiler)
– More common technology with broader service technician availability

Disadvantages:
– Major ductwork installation required in home with no existing ducts
– Significant disruption to interior spaces (drywall demolition for duct routing, soffit construction, register installation)
– Cast-iron radiator removal and disposal
– Loss of hydronic heating comfort characteristics
– Original home character impact from soffits and registers
– Floor space loss from required mechanical equipment closet/area

Project pricing for full conversion: $25,000–$40,000+ (furnace + AC + complete ductwork installation)

Customer selected Option A (modern boiler replacement). The forced-air conversion didn’t justify the cost, disruption, and character impact for this home. AC capability could be added separately through mini-split installation as future project if needed.

Equipment Selection

For the boiler replacement, three tiers discussed:

Option 1: Cast iron atmospheric-vent replacement (Burnham V8H series) — $9,500 installed
– Familiar technology, similar to existing equipment
– 85% AFUE typical
– Atmospheric chimney venting

Option 2: Mid-efficiency induced-draft boiler (Weil-McLain CGa series) — $11,800 installed
– 84% AFUE
– Induced draft venting allows smaller chimney or PVC venting
– Improved combustion control

Option 3: Modulating condensing boiler (Buderus GB142) — $14,200 installed
– 95% AFUE
– PVC venting (sidewall)
– Modulating burner matches load
– Best efficiency, quietest operation
– Federal 25C tax credit eligible ($600)
– Dominion Energy Therm-Wise rebate eligible (~$200)

Customer selected Option 3 (Buderus GB142 modulating condensing). The efficiency improvement, modulation, and applicable rebates justified the premium for long-term operation.

Project Scope

Work included:

1. Old boiler removal — drain system, disconnect electrical and gas, remove from boiler room
2. Existing radiator distribution assessment — verify radiators in good condition, check for leaks, document supply temperatures
3. System flush — flush existing radiator distribution to remove decades of accumulated sediment
4. Air vents and bleed valves — replace old radiator air vents, install new system air separator
5. Expansion tank — replace 22-year-old expansion tank with new diaphragm-type expansion tank
6. Circulator pump — replace original cast-iron circulator with new ECM (variable-speed) circulator pump for better efficiency
7. Zone valves — install zone valves on supply lines (two-zone setup: upstairs/downstairs)
8. New boiler installation — Buderus GB142 with proper clearances per manufacturer specifications
9. Gas line work — verify gas line capacity, install new shutoff and connection per manufacturer requirements
10. Venting work — PVC sidewall venting through exterior wall (lake-effect snow shield installed for Magna location)
11. Combustion air intake — proper outdoor combustion air intake
12. Condensate drainage — drain line with neutralizer to floor drain
13. Electrical connections — new 120V circuit for boiler
14. Smart thermostat — Ecobee compatible with boiler operation, two zones
15. Domestic hot water — existing separate water heater retained (not domestic hot water from boiler)

Installation

Duration: 2.5 days

Day 1 — Old equipment removal and prep:
– Old boiler drain and disconnect
– Cast-iron radiator system inspection and documentation
– Old boiler removal from boiler room (substantial weight required appropriate equipment)
– Chimney evaluation (no longer used after PVC venting installation)
– Boiler room cleanup and preparation for new equipment

Day 2 — New equipment installation:
– Buderus GB142 placement and mounting
– Gas line connection with shutoff
– Water supply and return connections to existing distribution
– Circulator pump installation
– Expansion tank installation
– Zone valve installation
– PVC venting installation through exterior wall
– Combustion air intake installation
– Condensate drainage with neutralizer
– Electrical connections

Day 3 (half-day) — Commissioning and documentation:
– System fill with proper inhibitor solution
– Pressure verification (12 PSI cold setting)
– Air purge across all radiators
– Combustion analysis at altitude-corrected settings
– Temperature differential verification
– Smart thermostat setup and zone configuration
– Customer walkthrough on system operation

Commissioning Measurements

Combustion analysis (altitude-corrected for 4,300 ft Magna elevation):
– CO ppm air-free: 6 ppm ✓
– O2: 8.4% ✓ (modulating boiler operates with higher excess air)
– Flue gas temperature: 130°F (proper for condensing operation)
– Combustion efficiency: 94.8% ✓
– Gas pressure inlet: 7.1″ wc ✓
– Gas pressure manifold (high-fire): 3.4″ wc ✓ (altitude-corrected)

Hydronic system:
– System pressure (cold): 12.5 PSI ✓
– Boiler supply temperature: 165°F (modulating, target range)
– Boiler return temperature: 145°F (20°F differential, proper for condensing operation)
– Circulator pump amp draw: 0.4 amps (ECM motor) ✓
– All radiators verified hot during heating call
– Zone valve operation verified across both zones
– Pressure relief valve verified operational

Final Cost and Rebate Filing

Customer’s project cost:
– Boiler equipment and installation: $14,200
– Existing system improvements (circulator, expansion tank, zone valves, air separator): $1,800
– Total: $16,000

Rebates filed on customer’s behalf:
– Federal 25C tax credit: $600 (modulating condensing boiler qualifying)
– Dominion Energy Therm-Wise rebate: $200

Total incentives: $800

Effective net cost after incentives: $15,200

Customer Outcome

First-winter feedback:

Comfort:
– Heating consistent across all rooms (improved from older single-zone operation)
– Quieter operation than old boiler
– Two-zone operation allows upstairs/downstairs temperature differences as preferred
– No interior space disruption (vs. forced-air conversion would have produced)

Energy:
– Gas usage compared to prior winter: approximately 28% lower (controlling for weather)
– Annual gas cost savings: approximately $480/year vs. old boiler
– Payback on premium equipment tier vs. atmospheric-vent replacement: approximately 7 years

Reliability:
– No service calls during first winter
– Annual maintenance scheduled through enrolled plan

Customer assessment: “Keeping the radiators was definitely the right decision. The home still has the character it should, and the new boiler is significantly quieter and more efficient.”

Future AC Consideration

We discussed future AC options with the customer:
– Multi-zone mini-split heat pump installation would provide cooling
– Could install in stages — one zone at a time as budget allows
– Heat pump portion qualifies for Federal 25C tax credit ($2,000) and potentially IRA rebates
– Estimated project cost when ready: $8,500–$15,000 depending on zones and equipment

Customer plans to consider mini-split installation in 2026 or 2027.

What This Case Study Demonstrates

• Boiler-to-forced-air conversion isn’t always the right answer — for homes without existing ducts, the conversion cost and character impact often don’t justify benefits
• Modern modulating condensing boilers preserve hydronic comfort while delivering significant efficiency improvements
• Comprehensive replacement scope — boiler replacement involves more than just the boiler (circulator, expansion tank, zone valves, air separator all benefit from replacement)
• Existing radiator distribution preserved — properly maintained cast-iron radiators are excellent heat distribution; no reason to replace working radiators during boiler replacement
• Lake-effect snow shield on PVC venting — Magna-specific consideration for sidewall venting termination
• Realistic efficiency improvement — 28% gas usage reduction is substantial without exaggerated marketing claims
• Future AC option preserved — mini-split installation possible later without compromising current investment

Considering Boiler Replacement?

If you have a boiler system in your Magna home and are considering replacement options, contact us or call (385) 250-0687. We provide honest analysis of boiler replacement vs. forced-air conversion options rather than defaulting to forced-air recommendations.

• Phone: (385) 250-0687
• Address: 4454 Manhattan Ct, West Valley City, UT 84120

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