Combi Boilers

rosaliedipietro2

I'm in the process of getting quotes to replace my existing gas boiler (for baseboard heating) and gas water heater with a combi boiler. Specifically, the Navien NCB-H. It's a two family property whereby each tenant controls their own thermostats....each apartment has it's own pump.

Has anyone installed this type of combi boiler and what has been your experience in terms of efficiency in providing heat and hot water and the cost savings.

Has anyone installed such a combi boiler in the NYC area and who have you used? Have you installed smart thermostats that you can control through wifi or the landlord thermostat by CCF?

Finally, I'm having difficulty in determining if a permit is needed from the Department of Buildings to replace an existing gas boiler....it's replacing the existing boiler and water heater in the same area of the current units. The company I'm thinking about using, run by a Master Plumber, says I should get one to avoid any DOB possible surprise inspections...this is at a cost of $2,500. I can't find anything on the DOB site that says I need a permit especially if I use a licensed Master Plumber. So confusing!!!

Thanks!

pecmsg

A 2 family property I’m almost certain a permit is required. 

Complain about the fee, I don’t even want to know what you get for rent!

go to the contractor locator section on the site. 

Hot_water_fan

Energy savings are determined by what boiler you’re replacing, who is replacing it, and the rest of the system, so estimates aren’t worth much unfortunately. It could be 0% to 40+% energy savings - dollar savings will be different as the price of fuel changes very frequently, so comparing 2022 dollars spent to 2021 dollars spent might be misleading. 

EdTheHeaterMan

Seems Pricy, Glad I don't live in NYC

Jamie Hall

I commented on the permit issue on your other thread (please use just one for the same project -- prevents confusion) and this one adds one thing not in the other -- this is a two family rental. Yes, you do need a permit. At least, that is, if you want to avoid the expense and hassle of getting shut down and your tenants on the street in case a building inspector happens by.

Now on the combi. Sometimes they are correct, if the water demand power can be sized to suit and the heating demand power can also be in the same unit. Then they do save some on installation, though not on maintenance. Otherwise, you may end up with too little hot water or too big a heating side (the usual case), and if too little hot water the tenants may not be too pleased -- and too big a heating side you won't save any money on your heating bill.

As @EdTheHeaterMan said, your savings on fuel could range between 0%, if the old units are in decent shape and well maintained -- and the installer does a quality job -- and 40% if the old units are very old or poorly maintained. Or, if the installer does a poor job, you could even wind up worse off...

Oh and you should be looking at heating contractors. Some plumbers are, and are very good at it. Some plumbers are wonderful plumbers, and clueless as to heating installations.

Alan (California Radiant) Forbes

I’ve had a few customers that don’t like to combine heating and DHW in one unit. If one goes down, they both go down and they choose to have a stand-alone boiler and a separate DHW heater. 

rosaliedipietro2

@pecmsg I hear what you're referring to regarding the rents. Do you want to know what the property taxes, insurance, utilities are in NYC? Lol

EBEBRATT-Ed

@rosaliedipietro2

I would strongly say away from Navian. If you want it done right pm @JohnNY

JohnNY

You need a permit to replace a gas boiler of any kind in NYC. There are basically two levels of permit: OP-128 and LAA. The "LAA" is the higher level of filing which is for moving or reconfiguring gas piping or in buildings with 6 or more units. That is a simplified explanation but it probably covers your purposes. If your installation does not require significant gas pipe reconfiguration then your OP-128 (Ordinary Plumbing-128) should cost a few hundred bucks. But then again, there are some variables.


Thank you @EBEBRATT-Ed for the recommendation.

pecmsg

rosaliedipietro2 said:

@pecmsg I hear what you're referring to regarding the rents. Do you want to know what the property taxes, insurance, utilities are in NYC? Lol

Moved out of there 25 years ago. Dont miss it at all!

Alan (California Radiant) Forbes

Moved out of there 25 years ago. Dont miss it at all!

Yeah, but what a town! I usually stay away from big cities, but NYC, Paris and SF are unique.

hot_rod

Most every combi boiler can be derate on the heating side. A 120,000 typically down to 13,000 BTU/ hr, close to a 10-1 tier down, there are a few claiming 12-1
so sizing one for 3 gpm or so in the DHW side, you still have the ability to have a 12,000 heating boiler

Show me an oil or cast gas conventional boiler that can do that?

So where is the argument for a lopsided losd profile? DHW to heat?

Installers with combi or even standard mod cons know the modulation is worth as much or more than the condensing

Dont fear the combis, they fit many needs, as do tankless water heaters

the key to either is in the DHW you expect.