Coleman Evcon DGAT070BDC furnace Parts

Replacing a 70,000 BTU gas furnace (like many homes use with a Coleman Evcon furnace) typically costs about $3,500 to $8,500 installed, depending on efficiency rating, venting changes, and labor in your area. For DGAT070BDC, the biggest cost swings come from installation complexity, not the BTU size alone.

What drives the total replacement cost

Here are the most common line items that change the price the most:

• Furnace efficiency (AFUE): higher-efficiency units cost more up front and may require different venting.
• Venting and combustion air: PVC venting, chimney liner work, or intake piping can add cost.
• Gas line and shutoff updates: resizing, relocating, or adding a sediment trap.
• Electrical and controls: new disconnect, wiring repairs, thermostat compatibility.
• Ductwork transitions: adapting the supply plenum, return drop, or filter rack.
• Condensate drain (high-efficiency): pump, drain routing, or neutralizer.

Typical cost ranges (installed)

These ranges are common for a 70,000 BTU class gas furnace replacement.

Scenario	What it usually includes	Typical installed cost
Basic like-for-like swap	Similar efficiency, minimal venting or duct changes	$3,500 to $5,500
Mid-range upgrade	Some venting, electrical, or duct transitions	$5,500 to $7,000
High-efficiency conversion	New venting, condensate drain work, more labor	$7,000 to $8,500

How to keep the quote accurate (and avoid surprises)

We recommend confirming these details before you approve a replacement:

• Match fuel type (natural gas vs propane) and verify the correct conversion setup.
• Confirm the venting path (chimney vs sidewall) and whether it must be rebuilt.
• Verify cabinet size and airflow so the new furnace fits the existing ductwork.
• Ask whether the quote includes a new filter rack or duct transitions.
• Confirm whether a new thermostat is required for staging or variable-speed blowers.

Why it matters

A 70,000 BTU furnace can be priced very differently depending on whether the job is a simple swap or a venting and condensate rework. Getting those installation details right protects comfort, efficiency, and safe operation.

If you are pricing parts for repairs versus full replacement, you can search by model number DGAT070BDC on the parts list for your furnace, or use Sears PartsDirect to look up additional diagrams and replacement parts by model.

Last updated: February 2026

A 70,000 BTU furnace like the Coleman Evcon DGAT070BDC typically heats about 1,800 to 2,800 sq ft, depending on your climate zone, insulation, ceiling height, and ductwork condition. For the most accurate sizing, match BTU output to your home’s heat loss, not just square footage.

Typical coverage ranges (what to expect)

Use these as practical planning numbers for a 70,000 BTU gas furnace:

• Warm climates: ~2,400 to 2,800 sq ft
• Moderate climates: ~2,000 to 2,400 sq ft
• Cold climates: ~1,800 to 2,100 sq ft
• Older or drafty homes: subtract ~10% to 25% from the estimate
• High ceilings (9 ft+): subtract ~10% to 20% unless the home is very tight

Quick sizing table

These rules of thumb help translate square footage into heating load.

Climate and home efficiency	Rule of thumb (BTU per sq ft)	70,000 BTU rough coverage
Warm, efficient home	25 to 30	~2,300 to 2,800 sq ft
Moderate, average home	30 to 35	~2,000 to 2,300 sq ft
Cold, average home	35 to 40	~1,750 to 2,000 sq ft
Very cold or leaky home	40 to 45	~1,550 to 1,750 sq ft

What changes the number the most

Square footage alone can be misleading. These factors usually swing the result the most:

• Insulation and air sealing (attic, rim joists, windows, doors)
• Duct leakage (especially in attics or crawlspaces)
• Ceiling height and open floor plans (more air volume to heat)
• Window area and quality (single-pane vs. modern low-E)
• Local design temperature (how cold it gets where you live)

Why it matters

An oversized furnace short-cycles (more starts and stops), which reduces comfort and can increase wear on the igniter, blower, and control board. An undersized furnace runs constantly and may still not keep up on the coldest days.

Getting the right parts for DGAT070BDC

When you’re ready to repair or maintain your furnace (filters, igniter, flame sensor, pressure switch, blower parts), use the DGAT070BDC model number to match parts correctly. Start with the parts list for this model, or search by model on Sears PartsDirect.

Last updated: February 2026

The Coleman Evcon furnace model DGAT070BDC is a heating furnace, so it does not have a true “tonnage” rating. Tonnage is a cooling (air conditioner/heat pump) capacity measure; your furnace is typically rated by BTU input/output, while the blower can be matched to a cooling system size.

What “tonnage” means for this furnace

In HVAC terms, 1 ton of cooling = 12,000 BTU/hr of cooling capacity. A furnace like the DGAT070BDC can be paired with different A/C sizes depending on the blower performance, ductwork, and static pressure.

Common ways “tonnage” gets associated with a furnace:

• The indoor blower is capable of moving airflow suitable for a certain A/C size.
• The furnace is installed with an evaporator coil that is sized in tons.
• A spec sheet lists a nominal cooling match (not a furnace heating rating).

How to identify the correct capacity for your system

Use these checks to confirm what your home actually has installed:

• Look at the outdoor A/C or heat pump nameplate; it often lists BTU/hr or a model code that indicates tonnage.
• Check the evaporator coil label (usually above the furnace in an upflow setup).
• Confirm the furnace’s BTU input from the furnace rating plate (often inside the burner compartment).
• Compare airflow needs: most systems target about 350 to 450 CFM per ton.

Quick reference table

What you’re trying to size	Correct unit	Where to find it
Air conditioner/heat pump capacity	Tons or BTU/hr cooling	Outdoor unit label
Furnace heating capacity	BTU input/output	Furnace rating plate
Blower capability	CFM at static pressure	Furnace/blower specs

Why it matters

Matching the right cooling tonnage to the blower and duct system helps prevent poor comfort, coil freeze-ups, high humidity, and noisy airflow. It also helps you order the right replacement parts for the correct configuration.

For parts lookup by model number and diagrams, start with the DGAT070BDC parts list, or search by model at Sears PartsDirect.

Last updated: February 2026

If your Coleman Evcon furnace model DGAT070BDC turns on (you hear the blower) but does not heat, the burner ignition sequence is failing or shutting down for safety. The most common causes are restricted airflow (dirty filter), a dirty flame sensor, or a high-limit trip.

Quick checks we recommend first

• Set the thermostat to Heat and raise the set temperature 3 to 5 degrees.
• Replace the air filter if it is dirty or high-restriction.
• Open supply registers and make sure return grilles are not blocked.
• Verify the furnace service switch is on and reset the breaker once if tripped.
• If there is a status light, write down the flash code before cycling power.

What the symptoms usually point to

What you notice	Likely cause	What to do
Blower runs, burners never light	Ignition or safety circuit issue	Check filter, power, and gas shutoff; then inspect ignition components
Burners light briefly, then shut off	Flame sensor not proving flame	Clean the flame sensor; check burner flame quality
Heat starts then stops; blower keeps running	Overheating/high-limit trip	Replace filter, improve airflow, check for blocked vents

Safe DIY steps (power off first)

• Change the filter and clear airflow restrictions.
• Clean the flame sensor with a non-abrasive pad if flames drop out quickly.
• Inspect wiring connectors for looseness or heat discoloration.
• If you use a meter, follow a guided process to avoid misreads.

For electrical testing basics, use how to use a multimeter to test electrical parts video.

Why it matters

No-heat with a running blower often means the furnace is preventing unsafe operation. Restoring airflow and reliable flame sensing helps stop short-cycling and protects the heat exchanger.

To look up diagrams and order DGAT070BDC parts by model number, use the parts list for this furnace or search on Sears PartsDirect.

Last updated: February 2026