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 6-10 of 28 reviews

"My unit lasted only 5.5 years"

2.0 rating
Somewhat Unsatisfied

I installed a ch240ng (Space & DWH combi) in 2012 after an oil->gas conversion. The unit worked very smoothly until the last summer when it started to generate noise when there's a heat demand (E.G. hot water faucet is on). A Navien trained tech examined the unit and concluded that the unit was beyond repair. A replacement is needed. I called another experienced tech who drew the same conclusion. Comparing to my old oil boiler which had worked with the problem for 24 years, my Navien unit has had only less than 6 years. If I knew this in 2012, I would consider twice before making this $2.5K investment. I also went through all the "very satisfied" reviews on this forum. I found none of them was from owners who had had their units for more than 5 years.

John Zhu

New Jersey


1.0 rating
Very Unsatisfied

Installed two CH-240 in a two-family house. I had and still have issues with a three-way valve, pump, etc. have paid over 3.000 in labor. I do not recommend them to anyone.

Daskarolis E

Little Neck, NY

"Heat Exchanges Leaking Water"

1.0 rating
Very Unsatisfied

Extremely unsatisfied. Exactly after 5 years, the heat exchangers are leaking water. The leakage has also caused all the components on the bottom of the unit to rust. I'm very concerned that at this point this is a serious safety hazard as the leakage will compromise the performance of the electrical, electronic and mechanical components for sure. The company in Canton, ma that installed the unit took pictures and videos a week ago but have yet to hear from Navien. This unit was installed under with incentives from Mass Save. Mass Save must track the performance of the boilers in the market and advise the customers to stay away from brands like Navien as they are not delivering on the promise of quality, safety and performance. I will wait to hear from my Plumbing company in Canton, Ma and if Navien and the Plumbing company (who purchased the Navien boiler on my behalf and completed the installation) do not handle this in a reasonable way I will contact a law firm. I will continue to post further developments on my case.

Erion Lamme

Canton, MA

"Not hiring a professional installer"

5.0 rating
Very Satisfied

I have install over 150 boilers over the past 5 years and less than 1% I have to go back to repair also Navien has a full package with 100% of parts that only trained contractors get when they are certified. So if you hire a contractor that doesn't know how to install or repair this boilers. You didn't ask enough questions and were trying to save some money now I had been call to fix over 50 Navien boilers last year because they hire someone that just wasn't to make some money and don't know how to trouble shoot them and 95% of them are wrongly installed. I had service all models and brands and they all will give you problems at some point in life. The only equipment out there that never gave any problem went out of business 60 years ago cause they couldn't sell any parts..


East Hartford, CT

"Don't waste your money"

1.0 rating
Very Unsatisfied

Well I usually don't write reviews one way or another but hopefully this will save someone some headaches.. I replaced my full size boiler and water heater with a ch240 navien combi boiler about 5 years 2 months ago.. The five years I have owned it has broken down at least once a winter.. Their trouble shooting consists of ordering parts and hoping for the best.. No one local stocks the parts so you order their best suggestion, wait two days after paying more for shipping then the part itself, install part, call back navien and get the next part they recommend for fixing it.. I usually had fixed it myself but I did have techs out 3 times who knew no more about the unit then I did.. Same thing, call navien, follow their suggestions and hope for the best.. Finally after being out of warranty two months the heat exchangers top plate had corroded and lifted causing air fuel ratio to no longer be correct and leaking carbon monoxide.. Unit is now garbage..Save your money for something better, we still have a month or two of the heating season left and I decided to let my gas fireplace handle the job until I can afford something good..

James Henninger


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