Old Coleman Evcon Furnace Repair, Identification, and Replacement Guide

The Coleman Evcon furnace series has served many U.S. homes for decades. This guide helps homeowners identify old Coleman Evcon furnaces, troubleshoot common issues, locate parts, evaluate repair versus replacement, and follow safety and code considerations. It focuses on practical steps and resources specific to aging Coleman Evcon systems.

Item	Quick Summary
Common Era	1960s–1990s models most common
Typical Fuel	Natural Gas or Propane, some oil models
Key Issues	Ignition failures, heat exchanger cracks, rust, blower motor wear
Parts Availability	Mixed — some OEM parts discontinued; aftermarket and salvaged available
Repair vs Replace	Replace recommended if >15–20 years, frequent repairs, safety concerns

History And Design Of Coleman Evcon Furnaces

Coleman Evcon traces back to several mid-20th century HVAC manufacturers later consolidated under larger brands. Models labeled Evcon or Coleman Evcon commonly appear in older residential installations across the United States.

Designs vary from basic standing furnaces with atmospheric burners to more advanced mid-efficiency models using induced draft blowers. Older units often lack modern safety and efficiency features such as electronic ignition, high AFUE ratings, or sealed combustion.

How To Identify An Old Coleman Evcon Furnace

Identification begins with the nameplate on the furnace cabinet. The nameplate contains model number, serial number, input BTU, and manufacturing codes.

Serial numbers on older units may encode date information. When serial decoding is unclear, photographing the nameplate and referencing manufacturer archives or HVAC forums helps determine age.

Visual Clues

• Stamped sheet metal cabinet with logo decals.
• Single-stage gas valve and standing pilot on very old units.
• Rust, flue venting into an older chimney or B-vent.

Common Problems With Old Coleman Evcon Furnaces

Wear and design limitations produce predictable failure patterns in older Coleman Evcon furnaces. Recognizing these helps prioritize repairs and safety checks.

• Ignition Issues: Faulty thermocouples, pilots, or obsolete gas valves.
• Heat Exchanger Cracks: Corrosion leading to carbon monoxide risk.
• Blower Motor Failure: Bearings wear, capacitor failure, or single-speed motors losing efficiency.
• Control and Limit Switch Failures: Age-related degradation in mechanical and early electronic controls.
• Rust and Corrosion: Moisture in basements and flue condensation cause metal deterioration.

Troubleshooting Steps Homeowners Can Take

Basic troubleshooting can identify obvious issues and prepare for an HVAC technician visit. Always prioritize safety: if carbon monoxide is suspected or gas smell is present, evacuate and call the gas company or 911.

Preliminary Checks

• Ensure thermostat works and batteries are fresh, and thermostat is set to heat mode with temperature higher than room.
• Check furnace switch and circuit breaker for power; reset tripped breakers with caution.
• Inspect pilot light or electronic ignition for normal operation; relight pilot only if trained or following manual instructions.
• Change or clean air filter; clogged filters cause overheating and limit trips.

When To Stop And Call A Pro

If the unit emits unusual odors, soot, visible cracks in the heat exchanger, persistent carbon monoxide alarm triggers, or complex gas-valve/electrical work is required, a licensed HVAC technician is necessary.

Safety And Code Considerations For Old Furnaces

Older furnaces may not meet current safety codes. Key concerns include sealed combustion requirements, flue sizing, gas piping, and electrical grounding.

Local building codes vary. A professional inspection can confirm whether the venting, clearances, and combustion air supply meet present-day requirements and recommend corrections.

Heat Exchanger Assessment And Carbon Monoxide Risks

The heat exchanger is a critical safety component. Cracks or holes allow combustion gases, including carbon monoxide, into the living space.

While visual inspection may reveal severe corrosion, only a qualified technician can perform a pressure or combustion analysis to definitively assess integrity. Installation of a properly calibrated carbon monoxide detector is essential when operating any older gas furnace.

Parts Availability And Sourcing For Coleman Evcon

Parts availability depends on model age and component type. Common parts such as blower motors, filters, capacitors, and universal gas valves are usually available from aftermarket suppliers.

OEM-specific components like proprietary control boards or obsolete pilot assemblies may be harder to find. Salvage yards, specialty online retailers, and HVAC parts distributors are primary sources.

Where To Look

• HVAC Parts Stores: Many stock universal parts compatible with older models.
• Online Marketplaces: eBay and HVAC-specific marketplaces may list NOS (new old stock) parts.
• Local Salvage/Yard: Useful for rare or discontinued panels and nameplates.

Repair Versus Replacement: How To Decide

Deciding between repair and replacement depends on age, repair history, efficiency, and safety. The industry rule of thumb favors replacement for units older than 15–20 years or with repeated major failures.

Consider replacement if the furnace has: frequent repairs, low AFUE (under 80%), cracked heat exchanger, inefficient blower, or lacks modern safety controls. Replacement often yields energy savings and improved indoor air quality.

Cost Factors

• Repair Costs: Typically lower if limited to parts like ignitors, thermocouples, or capacitors.
• Major Repairs: Heat exchanger replacement, control board swaps, or new burners can approach replacement cost.
• Replacement Costs: Vary widely—basic high-efficiency gas furnace plus installation may range significantly depending on brand, local labor, ductwork changes, and permit needs.

Finding Qualified Technicians And Warranties

Select a licensed HVAC contractor experienced with older systems and gas work. Verify licensing, insurance, and local code knowledge. Request references and ask about experience with Coleman or legacy brands.

When replacing, investigate manufacturer warranties and labor guarantees. A reputable installer provides system sizing (Manual J), proper venting, and permit handling.

Maintenance Tips To Extend Service Life

Regular maintenance can extend an old furnace’s life and improve safety. Even if replacement is planned, maintenance reduces interim risks and improves performance.

• Change Filters Regularly: At least every 1–3 months depending on use and filter type.
• Annual Inspection: Combustion analysis, flue inspection, and safety control testing by a professional.
• Clean Blower Assembly: Remove dust and lubricate motors if applicable.
• Check Venting and Chimney: Ensure clearances and no blockages.

Upgrading: Efficiency, Controls, And Ductwork

Upgrading to a modern furnace adds efficiency and comfort features like variable-speed blowers and electronic ignition. High-efficiency models improve AFUE and can lower utility bills.

Ductwork evaluation is crucial because poorly sealed or undersized ducts reduce the benefits of a new furnace. Proper sizing and sealing improve comfort and reduce energy waste.

Financial Considerations And Incentives

Replacement costs vary, but federal, state, and utility incentives sometimes apply to high-efficiency systems. ENERGY STAR certifications, tax credits, and local rebates can offset installation costs.

Financing plans from contractors, utility programs, or home energy loan options can help spread expenses. Always compare total cost of ownership including expected energy savings.

Case Examples And Common Scenarios

Example 1: A 1970s Coleman Evcon with cracked heat exchanger. Recommendation: Immediate replacement due to CO risk and poor efficiency.

Example 2: A 1995 Coleman Evcon with blower motor failure but solid heat exchanger. Recommendation: Replace blower if short-term solution is chosen, but plan for replacement within a few years due to age.

Example 3: Frequent pilot outages on an older unit. Recommendation: Replace obsolete standing pilot systems with electronic ignition or replace furnace for better efficiency.

How To Prepare For Replacement

Before replacement, gather the current furnace’s nameplate photo, serial number, and basic house details including square footage and insulation levels to help the contractor perform accurate sizing.

Request written estimates that include equipment specifications, AFUE ratings, installation scope, permits, removal of old unit, thermostat recommendations, and warranty details.

Resources And Where To Learn More

Useful resources include local building departments, HVAC trade associations, online forums for vintage HVAC equipment, and EPA/ENERGY STAR pages for efficiency guidance. Manufacturer archives or HVAC history sites may help decode serial numbers.

When in doubt, prioritize safety: hire licensed professionals for gas and combustion-related inspections and repairs.

Key Takeaways For Owners Of Old Coleman Evcon Furnaces

• Safety First: Check for heat exchanger integrity and install CO detectors.
• Age Matters: Consider replacement for units older than 15–20 years or with major failures.
• Parts May Be Limited: Source aftermarket or salvaged parts for rare components.
• Maintenance Helps: Regular service can delay replacement and reduce hazards.
• Get Professional Advice: Licensed HVAC technicians can perform combustion analysis and code compliance checks.

For homeowners seeking a next step, photograph the furnace nameplate, note symptoms and service history, confirm CO detector function, and contact a licensed HVAC professional for a diagnostic inspection and options review.