Help replacing Navien NCB-240 Combi-boiler

tau_

Hello,

I moved into a house that has an NCB-240 that has been giving me problems for the past 2 years. I've had plumbers come, I've done all the maintenance that has been shown in videos, and I've looked at all the videos online of the similar issues.

I just don't want to deal with it anymore.

My unit runs on propane. I don't know much about heating and these types of systems at all and would like to replace it. Can you guys give me a recommendation for a replacement from another brand? I don't minding spend more for better quality. It can be double the price of the NCB-240. I also wouldn't mind if the system was faster. I notice that sometimes it takes longer for me to get hot water. Not sure if that's just how all tankless systems are. Either way, any help would be appreciated.

(Right now, from looking on forums, my top choice for a brand is Rinnai. I'm just not sure which model I should get if I do go with them).

Hot_water_fan

Some combis have a tiny tank within them to have a store of DHW ready to go. Obviously, if you have space you can have a larger tank. That tank can either be connected to the boiler or independent of the boiler, there are pros and cons to both, but it’s more or less a coin flip. That’s if the problem is the lag from the heating of the water. If the problem is that the shower (or whatever) is far from the heater, the boiler can’t fix that. 

Here, tankless and combis mean different things, but everyday people use the terms interchangeably. So if you mean a boiler that doesn’t have a tank, that’s a combi. If you mean a Rinnai from Home depot, that’s probably a tankless, although they also make combis. It’s not as confusing as it sounds. 

Does this house have central AC?

tau_

hello, yes we do have central AC.

Hot_water_fan

hello, yes we do have central AC.

You might consider replacing it with a heat pump with (or without) a propane furnace included. It’s pretty easy to beat propane on energy costs, and it costs about the same as a new AC

kcopp

Tell us more about your system? What type of radiators? baseboard? panel rads?

I like the IBC SFC ...but I know the unit very well.

Whoever installs should know what they install very well.

tau_

i have a furnace, forced air. i have 2 zones. i have an air handler in the attic and in the basement. 2600 sq ft. 4 people in the house. 2.5 baths.

SuperTech

Back to the original topic, tankless water heaters. Rheem is another good brand. But does it have to be tankless? In my area tankless water heaters tend to be high maintenance and have short lifespan due to the water quality. We have found tank style water heaters fare better and are less maintenance.  A propane 40 gallon water heater is a relatively inexpensive option.  Electric heat pump water heaters are another option but will be more expensive and requires some electrical work to be done with the job, a new double pole breaker and wire will need to be run to the heat pump water heater. 

Anything is preferable to your current water heater in my opinion. 

kcopp

original topic was a combi boiler....

Hot_water_fan

Does the Navien supply heat to the house or just heat domestic hot water?

SuperTech

Hot_water_fan said:

Does the Navien supply heat to the house or just heat domestic hot water?

The OP stated the house has a furnace.  That leads me to believe we are discussing a tankless water heater, not a combi. The title of the thread is a bit misleading 

Hot_water_fan

The OP stated the house has a furnace.  That leads me to believe we are discussing a tankless water heater, not a combi. The title of the thread is a bit misleading 

Could be a boiler with air handlers! We’ll see. 

tau_

Hi, I called it a combi-boiler because when I googled my model, that's exactly what it says on their website. But yeah, I don't know much about this stuff.

The Navien does supply heat too. I have 2 air handlers, one in the basement and one in my attic.

I want a direct replacement just to make things easier for the plumbers. I figure it wouldn't take much work to remove the Navien and put in a new unit, compared to getting something totally different. If they could install the Navien then I would assume they can Install a Rinnai or a Rheem. I'm just not sure what model to get to be of equal or better quality to the NCB-240 in terms of stats. I don't really know what any of the stats for the units mean besides GPM.

My current NCB-240 was converted using their kit to accept propane. I have a 500 gallon propane tank.

SuperTech

Hot_water_fan said:

The OP stated the house has a furnace.  That leads me to believe we are discussing a tankless water heater, not a combi. The title of the thread is a bit misleading 

Could be a boiler with air handlers! We’ll see. 

Nice job. I wasn't considering it doing Hydro Air.