Navien Combi CH-240 Boiler Overview

The Navien Combi CH-240 is an on-demand combined ("combi") unit which heats water for central heating as well as for hot showers. This tankless boiler can be set up either inside or outside the house.

Features and specifications of the Navien Combi CH-240

  • It has two non-corrosive stainless steel heat exchangers. The heat exchangers have an energy efficiency of 91% when using natural gases and 92% when using propane.
  • It comes with a remote control that includes water temperature control, 24 hour scheduling and a user-friendly LCD display.
  • This boiler comes with an external sensor. Any changes in external temperature will lead to an automatic response from the boiler to either initiate central heating or halt it.
  • It has a built-in water leak detector and carbon monoxide monitoring system.

Safety precautions when using the Navien Combi CH-240

  • Ensure the boiler is adequately vented.
  • Ensure the water temperature is regulated, especially when children and the elderly are in the house. Do not set the water temperature above 125° F.

Questions about this model?

Consumer Reviews of Navien Combi CH-240


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #3 of 4 Navien Boiler
  • 10.34% of customers recommended

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Navien Combi CH-240 Boiler Reviews

Showing 26-28 of 28 reviews


1.0 rating
Very Unsatisfied

You do not want to buy Navien. They made my heating guy wait 45 minutes for tech support, I waited 38 and my buddy waited 24. The tech then told me the part number I needed after I gave him my serial number of the unit. That cost me another 6 hours in 18 degree weather and a full day lost waiting for part. We then learn the correct part number but the distributor doesn't have it in stock. I drive 75 miles to another location. That afternoon after another 45 minute phone wait we need to drive to another location 76 miles away. 4 homes I built have them installed and I will now switch brands. 3 days with no heat or hot water, 300 miles,10 dollars in tolls and I will tell anyone listening, "don't buy this company's service" it sucks.

Bill M

New York


1.0 rating
Very Unsatisfied

I had plumbers install my first Navien in 2010. This boiler started giving me problems three short years later, to the point where I had to unplug and plug it back in to get it to work..I spent lots of money on repairs. I also had to wait for parts because plumbing supply stores don't carry many parts for combi boilers. Spent countless hours on the phone with rude Navien personnel, finally received a new unit less than two years ago and had plumbing redone by a certified plumber…and now am having problems again. Wish I had stuck with my 25 year old boiler!

J waltonen

Rhode Island

"Very Happy with Navien On Demand Boiler"

5.0 rating
Very Satisfied

I had this boiler installed 3 years ago after reading many positive and negative reviews. I was a little nervous but found a plumber with specific experience installing this type of boiler. I use the boiler for both on-demand hot water and heating for my house. This replaced a separate boiler and water tank system. My experience with it has been nothing but positive. It is very economical, low maintenance and the space saving over conventional boilers and tank is huge. My house is quite small so I got a lot of bonus storage space out of the conversion. My gas bills dropped significantly as I was not having to keep a water tank hot. The only negative is that it can be a little loud so it depending on placement that might be annoying. So far I have had to clean the filters but it has not required any other maintenance. I would definitely buy this boiler again and strongly recommend it to a friend. The only caveat being that you really need a good plumber that is specifically experienced with this boiler manufacturer. It is a very complex system and I read a lot about poor installations, which caused the homeowners a lot of problems. Thankfully my personal experience has been great.

Belmont, MA

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