Coleman Evcon DGAT075BDD furnace Parts

For a Coleman Evcon furnace model DGAT075BDD, the furnace age is encoded in the serial number on the rating plate; once you match the serial format to the correct decoder, you can identify the manufacture month and year and calculate the unit’s age. Use the DGAT075BDD installation guide as a starting point for locating service panels and labels.

Where to find the serial number on a DGAT075BDD

On most furnaces, the serial number is printed on the rating plate or a manufacturer label. Common places to check:

• Inside the burner compartment behind the front access door
• On the inside face of the upper or lower door panel
• Near the gas valve area or burner inlet area
• On the blower compartment panel
• Occasionally on the side panel of the cabinet

How to decode the serial number (what to look for)

Coleman Evcon serial formats vary by production era, but most decoders use one of these patterns:

• Month and year embedded early in the serial (often the first 4 digits)
• Week and year format (for example, YYWW or WWYY)
• Letter-coded month plus a digit-coded year

Quick decode checklist

• Write down the entire serial number exactly as shown (include letters).
• Note the model number DGAT075BDD from the same label.
• Look for a 2-digit year or a 4-digit date block within the serial.
• If you see a week number (01-52), pair it with the year to estimate the build date.

Example: turning a build date into “how old”

If the serial decodes to April 2014, then as of February 2026 the furnace is about 11 years and 10 months old.

What you decode	What it means	What you can say
Month + year	Exact build month/year	“Built in April 2014”
Week + year	Approximate build time	“Built around week 18 of 2014”

Why it matters

Knowing the manufacture date helps us choose the right repair approach and parts strategy for your Coleman Evcon furnace, especially for age-related issues like ignition problems, blower wear, or heat exchanger inspection steps referenced in the DGAT075BDD installation guide.

If you need to look up parts by model after you confirm the serial format, search by DGAT075BDD on Sears PartsDirect.

Last updated: February 2026

A 60,000 BTU furnace typically heats about 1,200 to 2,000 sq. ft. In the Coleman Evcon DGAT075BDD, the installation specs list about 61,000 BTU/hr output for the DGAT075 series, so real coverage still depends on your climate, insulation, ductwork, and ceiling height; see the installation guide for model specs.

Quick sizing rule of thumb (what changes the square footage)

We size furnaces by the home’s heat loss, not just square footage. These factors move the number up or down:

• Climate zone (cold regions need more BTU per sq. ft.)
• Insulation and air sealing (attic, walls, rim joists, weatherstripping)
• Windows and doors (age, glazing, drafts)
• Ceiling height (taller ceilings increase volume to heat)
• Duct condition (leaks, poor airflow, high static pressure)
• Furnace output vs. input (output is what actually heats the home)

Typical coverage ranges for ~60,000 BTU output

Use this as a practical planning range for a furnace around 60,000 BTU/hr output.

Home condition / climate	Typical BTU per sq. ft.	Approx. sq. ft. for ~60,000 BTU output
Mild climate, tight/insulated home	25 to 30	2,000 to 2,400
Moderate climate, average insulation	30 to 40	1,500 to 2,000
Cold climate, older/drafty home	45 to 60	1,000 to 1,300

Why it matters

Oversizing can cause short cycling, uneven temperatures, and higher wear on parts like the igniter, gas valve, and blower. Undersizing can mean long run times and rooms that never reach set temperature.

Best next step for accurate sizing

For the most accurate answer, we recommend a Manual J heat-loss calculation (or an equivalent load calculation). If you are comparing furnaces, focus on BTU output and confirm airflow and duct static pressure are within spec for your setup.

If you need help finding the correct parts list for your exact furnace configuration, search by model number on Sears PartsDirect.

Last updated: February 2026

If your Coleman Evcon furnace model DGAT075BDD is running but not heating, the blower is moving air but the burners are not igniting or not staying lit. The most common causes are thermostat or power issues, restricted airflow (filter or ducts), or an ignition or flame-sensing problem.

Quick checks we recommend first

• Confirm the thermostat is set to Heat and the setpoint is above room temperature.
• Make sure the furnace power switch is ON and the breaker is not tripped.
• Replace a dirty air filter and open all supply registers.
• Verify the manual gas shut-off valve is fully open.
• Watch a heat call cycle: inducer starts, igniter glows/sparks, burners light, then blower starts.

What the DGAT075BDD installation guide points to

Your installation guide includes steps that directly relate to “runs but no heat” situations:

• Combustion air and venting: Remove bird screens or other obstructions at the combustion air inlet; a blocked inlet can prevent proper ignition and safe operation.
• Ignition and flame proving circuit: The guide references disconnecting wires to the gas valve, igniter, and flame sensor during service; loose or damaged wiring at these components commonly causes no-heat symptoms.
• Temperature rise check (ATR): After at least 5 minutes of operation, measure return vs. supply temperature to confirm the furnace is firing correctly and operating within the rating-plate range. Use the installation guide for the measurement locations and process.

Symptom-to-cause guide

What you observe	Likely cause	What to do next
Blower runs, burners never light	Thermostat, gas supply, igniter, pressure switch/venting	Check gas valve open, clear intake/exhaust, inspect igniter wiring
Burners light then shut off quickly	Dirty flame sensor, poor grounding, airflow/limit issue	Clean flame sensor, check filter and airflow
Burners stay on but air feels cool	Low firing rate or duct/airflow issue	Check ATR; verify gas pressure and duct static per guide

Why it matters

A furnace that moves air without stable burner operation can indicate a safety shutdown (flame not proven, overheating, or venting/combustion air problems). Fixing airflow and ignition issues restores heat and helps prevent repeated cycling and component wear.

Parts and diagrams

If you need to identify components (igniter, flame sensor, gas valve, pressure switch tubing) for your DGAT075BDD, start with the diagrams and parts list for this model, or search by model number on Sears PartsDirect.

Last updated: February 2026

To hard reset a Coleman Evcon furnace model DGAT075BDD, we cycle power to fully reboot the control board: turn the thermostat to OFF, shut off power at the furnace switch or breaker for a few minutes, then restore power and call for heat. Use the installation guide for model-specific shutdown steps.

Hard reset steps (safe, standard method)

• Set the thermostat to OFF.
• Turn the furnace power switch to OFF (many furnaces have a service switch near the unit).
• Turn the furnace circuit breaker OFF as well.
• Wait 3 to 5 minutes (this clears many lockouts and reboots the control).
• Turn the breaker ON, then the furnace switch ON.
• Set the thermostat to HEAT and raise the setpoint 3 to 5 degrees to start a heat call.

Before you reset: quick checks that prevent repeat lockouts

• Replace or clean the air filter; restricted airflow can overheat the furnace and trip safety limits.
• Confirm the thermostat has power and is set to HEAT.
• Make sure supply registers and return grilles are open and not blocked.
• If you recently had work done, verify the furnace doors/panels are fully seated (many units have a door switch).

If your DGAT075BDD has a reset button, use it correctly

Some furnaces include a manual reset on a rollout switch or limit switch. If you find a small button on a safety switch:

• Press it once after the furnace has cooled.
• If it trips again, stop resetting and correct the cause (airflow restriction, venting issue, burner problem).

What to do if it still will not run

Use this table to decide the next step after a hard reset:

What you see	What it usually means	What we do next
Blower runs, no heat	Ignition or gas issue	Verify gas is on; check for ignition sequence and error light codes
Furnace starts then shuts off	Flame sensing or airflow issue	Check filter, vents, and burner flame stability
Nothing runs at all	Power/control issue	Recheck breaker, service switch, and door switch

Why it matters

A hard reset clears many temporary control-board lockouts, but repeated trips point to a safety condition (overheating, ignition failure, or gas supply problems). Fixing the root cause protects the heat exchanger, gas valve, and ignition system.

To look up diagrams and replacement parts by model number, search DGAT075BDD on Sears PartsDirect.

Last updated: February 2026

On a Coleman Evcon furnace like model DGAT075BDD, the most common failures we see are the flame sensor, igniter (hot surface or spark), and airflow-related safeties that trip because of a dirty air filter. These issues commonly prevent ignition or cause short cycling.

Most common furnace failure points

• Air filter (maintenance item): Restricted airflow leads to overheating and a limit switch trip.
• Flame sensor: Gets coated and stops proving flame; the control shuts the gas valve.
• Igniter: Cracks or weakens; burners never light.
• Pressure switch: Opens when venting or combustion air is restricted.
• Limit switch or rollout switch: Opens on overheating or flame rollout conditions.
• Thermostat or low-voltage wiring: No steady call for heat.

Quick checks you can do first

• Replace the air filter and confirm supply and return registers are open.
• Verify thermostat is set to HEAT and set above room temperature.
• Confirm the furnace power switch is on and the breaker is not tripped.
• Make sure the blower door/panel is fully seated (many furnaces have a door safety switch).
• If burners light then shut off within seconds, clean the flame sensor.

Symptom-to-part cheat sheet

Symptom	Likely part or cause	Next step
Inducer runs, no ignition	Igniter, pressure switch, vent restriction	Inspect igniter; check venting and tubing to switch
Lights then shuts off fast	Flame sensor	Clean sensor; check flame signal wiring
Runs briefly, then stops and repeats	Airflow, filter, limit switch	Replace filter; check for blocked returns/registers
Blower runs, air is cool	Thermostat setup, gas supply, ignition system	Confirm thermostat settings; verify gas shutoff is open

Why it matters

Misdiagnosing a simple airflow or flame-sensing problem can lead to unnecessary parts replacement and repeated safety shutdowns. The installation guide for DGAT075BDD includes shutdown steps and checkout items (such as venting and temperature rise checks) that help confirm safe operation after service.

For parts lookup by model number, use the DGAT075BDD parts list or search by model on Sears PartsDirect.

Last updated: February 2026