[kjmass1]

I was looking in to tankless hot water heaters and my current NG supply lines. I have a 250 CFH regulator with 1.5" pipe feeding a 196K BTU steam boiler and a 3/4" line going to my existing hot water heater and Pro range.

Do I need to size my NG supply for everything running at once? I would need:

196k Boiler
199k Tankless WH
100k Range (4x 18k burners, 25k oven)

That's almost 500k BTU or 488 CPH. Are people really getting the gas company to come out and install new regulators? Seems like a lot of $$ when I could just swap out the hot water heater for $500.

Thanks.

 

[ct18]

Back in 08 when i went back to the field for a year people were paying 700 for the gas upgrade. then add the cost of the tankless install and they were over 2 grand. The tankless was all the craze back then and people were getting rebates on there bills by switching to the tankless. I hate the things and would never install one unless i had a big jacuzzi tub or just didn't have the space for the power vent.

 

[kjmass1]

Back in 08 when i went back to the field for a year people were paying 700 for the gas upgrade. then add the cost of the tankless install and they were over 2 grand. The tankless was all the craze back then and people were getting rebates on there bills by switching to the tankless. I hate the things and would never install one unless i had a big jacuzzi tub or just didn't have the space for the power vent.

Thanks, that's good to know. Seems like the breakeven point is pretty high.

My gas bill is $30/mo in the non-heating months. It's going to take a while to recoup $$ no matter how efficient it is.

 

[Bondo]

Ayuh,.... What are the odds of the boiler runnin', 'n the tankless heater runnin', 'n havin' every single burner, 'n oven in yer range runnin',....
ALL at the same time,.....

If ya wanta go tankless, just hook it up at the line ya got now for the water heater,....

It might make more sense to run a branch circuit off yer existin' boiler to a DHW exchanger,....

 

[2x_Tom]

Do I need to size my NG supply for everything running at once?

Yes. The meter and supply lines must be sized for everything running at one time. You may not get proper combustion if your appliances are being starved of fuel.

Another option is to go with a combi condensing boiler. Getting 85-95% efficient heat will save you a lot more money then 85-95% efficient hot water and loosing the minor standby loss on the tank. That of course would entail ditching your steam system.

 

[kjmass1]

Yeah I don't think I want to lose my one pipe steam system.

Ever heard of a Phoenix hot water heater? It's like 97% efficient tank HWH but expensive- about $2k plus install.

From researching a bit more I have some hesitation going to tankless. Cost, yearly warranty maintenance and long ROI are concerns. Thanks for the input.