Any experience with Navien boilers.
- Thread starter TubingJon
- Start date
Yes. I have installed countless tankless water heaters and boilers. Navien has been the best for us. Customer service is top notch and we've had the fewest calls for Navien. When you go with the Navien boiler make sure to order their manifolds also. It saves a lot of install time. Plus you can vent with pvc.
To each his own, but I haven't had a lot of luck with Navien. Rather than writing a lengthy dissertation on the issues I've had, I'll just say that in my opinion the heat exchanger design has caused my problems.
The short version is that Navien uses a stainless heat exchanger. That sounds good, but since stainless doesn't transfer heat as well as copper the manufacturer has two basic choices:
1) Make the heat exchanger larger (surface area)
2) Make the pathways the water goes though smaller
They chose to make the pathways smaller. The end result is a significantly higher pressure drop at "useful" flow rates (4-7 gpm).
Do a little homework and take a look at the pressure drop curves on Navien vs. Rinnai, A.O. Smith, Noritz, Takagi.
I think you'll be surprised.
Best of luck,
Reflex
The short version is that Navien uses a stainless heat exchanger. That sounds good, but since stainless doesn't transfer heat as well as copper the manufacturer has two basic choices:
1) Make the heat exchanger larger (surface area)
2) Make the pathways the water goes though smaller
They chose to make the pathways smaller. The end result is a significantly higher pressure drop at "useful" flow rates (4-7 gpm).
Do a little homework and take a look at the pressure drop curves on Navien vs. Rinnai, A.O. Smith, Noritz, Takagi.
I think you'll be surprised.
Best of luck,
Reflex
pstnbly
Well-known member
If you can't afford the heat to go down why not use a real boiler and an indirect water heater? There seems to be meme on this board that the proper device to drive radiant infloor heat is a "water heater" when in actuality it should be a properly sized (though heatloss calculation) heating appliance, I.E boiler. A quality boiler with a proper install will show a payback over time in maintenance, repairs, and downtime over asking a machine designed more for water heating than space heating.
mopar440_6
Well-known member
The Navien NCB240E IS a dedicated heating appliance, I.E. on demand BOILER. Not a HW heater.
shelteredV
Well-known member
I have used Navien twice, one with a domestic circuit and one without. They are both lit with propane and needed to be fine tuned by my HVAC guy to get them to run right and not make that gawdawful howling noise. Other than that, they haven't missed a beat.
To run your radiant, I wouldn't mess around. I am running my shop on little baby Weil McClain 42,000 BTU low mass boilers. The only thing they are doing is running the radiant loops, 4 runs in each bay. Very simple and pretty bullet proof. I will get more details if you want me to.
To run your radiant, I wouldn't mess around. I am running my shop on little baby Weil McClain 42,000 BTU low mass boilers. The only thing they are doing is running the radiant loops, 4 runs in each bay. Very simple and pretty bullet proof. I will get more details if you want me to.
I currently run 5000 square feet of radiant heat in my house including my garage with a Knight boiler, never a hiccup in 9 years. It does my domestic also but the shop only has one full bath and no need to maintain DHW all the time, that is why the combi boilers are so appealing. I just want to do it right the first time, if using a regular boiler and a small water heater or on demand is the answer then so be it.
1 year and countless service calls later I took it off the wall and replaced it with a real boiler and an indirect. Navien doesn't cover labor on any warranty calls, they stick the bill with the owner. The factory service tech quit his job a week after his 3rd visit to my house because in his words he "didn't get paid enough". It's a glorified water heater. I think they're still only rated for like 4.5gpm max. If you call for domestic hot water forget about getting heat at the same time. Spend the extra money and get a real boiler. Like mentioned above Lochinvars Knight boiler is a great choice.
redneckcharlie
Well-known member
- Joined
- Dec 26, 2009
- Messages
- 125
Interesting. I sell and service them. Any warranty issue is handled quickly. Parts are usually over nighted. I've always recieved a check for warranty work in 7-10 days. I've only had 3 service calls on them to this point. The biggest issue with all tankless units is improper supply line size. Rinnai makes a great unit as well. Naviens tech and dealer support is top notch. For reference thats in the last five years.
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mygarageone
Well-known member
I've never installed a Navien but all high eff boiler are subject to trouble if there not installed correctly and that means pumping , piping , venting and sizing.
Follow the installation manual period .
Yes the old style cast iron boiler sare bullet proof but I haven't installed on for yrs now .
Follow the installation manual period .
Yes the old style cast iron boiler sare bullet proof but I haven't installed on for yrs now .
My service tech had a cargo van supplied by Navien with all parts on board. The labor was never reimbursed no matter how many phone calls and emails I sent. I had the CH240 and I believe the largest piping it could accommodate was 1" and that's what was used. I had the factory rep out along with the service tech and they found no issues at all with the piping. Even when it would run ok for a stretch of time the blower noise would drive you crazy. My gas bills were crazy also. When I installed the new boiler my daily therm consumption dropped by 36% on average. My gas bills went from $400+ a month to $275ish.
Reviving this thread, I am also considering a Combi unit. The input BTU ranges of the Navien or Noritz combi "boiler" loops appear to be the best suited for my application.
For the guys with the Navien combi (or Noritz), how has the reliability been?
For the guys with the Navien combi (or Noritz), how has the reliability been?