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Navien CH-240-ASME LP Condensing Gas Combination Boiler

Original price $2,949.00 - Original price $2,968.95
Original price
$2,949.00 - $2,968.95
Current price $2,949.00


Get a high performance condensing tankless water heater and space heater in one.

Navien-CH-ASMECombination Boiler: Where Technology Meets Ecology

→ Heats water only when needed, making it environmentally sound and cost efficient.
→ The ideal solution for people who need both a space heating application and a domestic hot water heater.

Benefits of Hydronic Heating

→ Clean: no air movement means very little chance for dust buildup to lower humidity.
→ Silent: silent heating, with no blowers needed for forced circulation.
→ Comfort: makes people feel warm and comfortable by keeping the floor warm and indoor air fresh.
→ Coverage: radiant heat from the floor to the ceiling.
→ Economical: radiant heat from the floor can send warmth throughout the house even hours after turning off your heater.


PVC Venting

• Low cost PVC venting solution for a fast, simplified installation.
• Venting up to 100 feet with up to six elbows (each elbow reduces venting length by 5 feet).

Durable Stainless Steel Heat Exchanger

• Ensures a longer life expectancy than copper heat exchangers.
• Prevents corrosion with integrated primary and secondary heat exchangers.
• Stainless steel components remain intact, even during long period of use.

Premixed, Eco-friendly Burner

• Modulates air and gas ratios needed for optimal combustion.
• Built-in system monitors CO levels and will shut down the unit in the event of hazardous CO build up.

Leak Detector

• Prevents water damage to the heater as well as to your property.

Low-nox-emissionsLow NOx Emissions

• New metal fiber burner delivers a consistent gas/air mixture
• Less greenhouse gas emissions and acid rain

Automatic Water Filling System

• Automatically fills the space heating pipes with water when the unit senses water shortage.

Powerful Anti-Freeze Feature

• Built-in Control System keeps the unit's plumbing frost free in winter.

Intelligent Remote Control System

• Included with each unit
• Easy to read LCD display
• Easy-to-Use button type control
• Matches any home's interior design
• 24 Hour scheduling for space heating applications
• High-Precision Water Temperature Control with 1°F Increments

asme-logo NSF logo ahri-seal CSA-certified


CH-180 CH-210 CH-240, CH240 ASME
Heat Capacity (Input) Min 17,000 BTU/hr.
Max 150,000 BTU/hr
Min 20,000 BTU/hr.
Max 175,000 BTU/hr
Min 20,000 BTU/hr
Max 199,900 BTU/hr
Flow Rate (DHW) at 77°F Rise 3.4 GPM 4.0 GPM 4.5 GPM
Dimensions 17" × 28" × 12" 17" × 28" × 12" 17" × 28" × 12"
CAAFUE Natural Gas 91% 91% 91%
CAAFUE Propane Gas 92% 91% 91%
Weight 74 lbs 84 lbs 84 lbs
Installation Type Indoor / Outdoor Wall-Hung Indoor / Outdoor Wall-Hung Indoor / Outdoor Wall-Hung
Venting Type Direct Vent Direct Vent Direct Vent
Ignition Electronic Ignition Electronic Ignition Electronic Ignition
DHW Pressure (min-max) 15 - 150 PSI 15 - 150 PSI 15 - 150 PSI
Heating Pressure (min-max) 7 - 30 PSI 7 - 30 PSI 7 - 30 PSI
Gas Supply Pressure (Natural Gas) 5.5" W.C. ~ 10.5" W.C. 5.5” W.C. ~ 10.5” W.C. 5.5” W.C. ~ 10.5" W.C.
Gas Supply Pressure (Propane Gas) 10.5" W.C. ~ 13.5" W.C. 10.5” W.C. ~ 13.5” W.C. 10.5” W.C. ~ 13.5" W.C.
Minimum Flow Rate (DHW) 0.5 GPM 0.5 GPM 0.5 GPM
Heating Supply / Return 1” NPT 1” NPT 1” NPT
DHW Inlet / Outlet 3/4” NPT 3/4” NPT 3/4” NPT
Auto Feeder 1/2” NPT 1/2” NPT 1/2” NPT
Gas Inlet 3/4” NPT 3/4” NPT 3/4” NPT
Main Power Supply 120VAC, 200W (max 2A) 120VAC, 200W (max 2A) 120VAC, 200W (max 2A)
Heat Exchangers Primary Heat Exchanger: Stainless Steel Condensing Heat Exchanger: Stainless Steel Primary Heat Exchanger: Stainless Steel Condensing Heat Exchanger: Stainless Steel Primary Heat Exchanger: Stainless Steel Condensing Heat Exchanger: Stainless Steel


Operation Manual

Installation Manual

FAQ (Frequently Asked Questions)

Q1: I would like to buy this Navien heater to replace another water heater that uses metal vent pipe. I read the manual that describes various PVC products to use for venting. The manual does not state that metal should not be used. Are there any performance issues if I use my metal exhaust vent pipe and not the PVC type pipe?

A1: Yes, the reason for using PVC versus metal is for energy efficiency. Navien recommends using PVC because the NPE and NR heaters are condensing type heaters. Using PVC provides the maximum condensing function. The Navien heaters will run more efficiently with PVC.

Yes, you could use your metal venting instead of PVC; the heater will still work safely. Alternatively, you could install the PVC inside the metal venting, using the metal venting as a chase (like a conduit).

Installation Help and Recommendations

We recommend that you have a professional tankless water heater installer review the above recommendations. Improper installation may cause loss of life and/or property. Need an installer? Get 4 FREE Tankless Water Heater Installation Estimates Now. It's Quick and Easy!
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All items for sale on are genuine and new, not used. The NAVIEN, KD NAVIEN, ComfortFlow, Ready-Link, and NaviLink trademarks are the property of Navien America, Inc. and/or KyungDong Navien. Navien is not affiliated with and does not sponsor, endorse or warranty/support or products on this website.

Alternate model number spelling: CH240ASME