Lochinvar Noble vs Indirect

blaw

Hi. I'm new and an amateur. I live on Long Island, NY, in a ~2,500sq ft high ranch, with baseboard heating, 3 full baths, including 1 with jacuzzi, rain shower head and body sprays. Household includes 2 adults, and 2 teens. My current 50 y/o cast iron boiler (145,000 btus) and 50 gallon HWH is ready to give out. We never had any issues with getting enough heat and hot water under current setup for daily use (jacuzzi didn't fill up with hot water but not a big deal since we barely used it). The current equipment is in a tight space in a utility room. I would really like to put in a water filtration system in this space with a descaler since my water is fairly hard (looking at the Aquasana Rhino Pro which needs a lot of space). I have 3 proposals from 3 reputable plumbers:

1) Burnham x206 175,000 btu boiler with Burnham Alliance (AL50SL) 50 gallon indirect tank (most economic option)
2) Burnham 230,000 btu atmospheric boiler with Techtanium indirect tank (most expensive option)
3) Lochinvar Noble 199,000 btu (priced in-between both options, but still expensive)

I like the idea of atmospheric boiler and indirect for the reliability and the simplicity (and it should adequately serve my needs), but I would not gain any space and won't be able to put in the water filtration system (which I really want).

I think the 1st option should be sufficient, while the 2nd option might be oversized (thoughts on this?).

I also like the 3rd option because I gain space and could put in the water filtration system. While I like the idea of going with newer technology, I am concerned about "more things going wrong" (under my old system, I barely thought about it other than scheduling annual tune-ups with local service companies), and finding people that I could trust to service it (so more expensive maintenance). Everything I've heard and read about the Lochinvar Noble so far seems to be positive, but I understand that this system has only been around for about a year, so it doesn't have much of a track record yet. Also, I'm not sure if the system is appropriate for my needs (any advice here?). Even though we don't use the jacuzzi or body sprays often, I would like to know that we could (and I'm not sure if I should be concerned about "cold water sandwiches"?)

Any good advice on which option to pick? I would like to pick Option 3 if I could get more reassurances on my above concerns. And if the advice is to go with Options 1 or 2, then any suggestions on a good whole-house water filtration system which includes water softener and can fit in only ~2ft wide space (and won't break the bank)?

Thanks!

DZoro

I have been impressed with the Lochinvar Noble, simple design, stainless fire tube, easy to work on if needed. Noble has the cold water sandwich figured out nicely.
Like with any, when installed and set up properly, it will give you good service.
IMO water filtration is a must with any of these systems.

hot_rod

Was a heat loss calculation performed to size those options? Seems odd that you would need a bigger boiler than what currently is adequate? I'd guess you would need more around 100,000 BTU/hr on that size home, maybe?

At issue with a combi is the fact to provide DHW at the rate you want it will be way oversized for the heating load. It may short cycle.

I own the small Nobel 110,000 in my 2200 sq ft home and have been pleased with it's performance. Plenty of DHW for two of us if you plan your DHW use, one fixture or hw load at a time, as you provides around 2 gpm hw.

blaw

@hot rod "Was a heat loss calculation performed to size those options? Seems odd that you would need a bigger boiler than what currently is adequate? I'd guess you would need more around 100,000 BTU/hr on that size home, maybe?"

I guess it was bc under current setup, I couldn't fill up Jacuzzi, so they wanted to make sure I had big enough indirect tank.

With Noble, I don't have any problem with planning DHW use for Jacuzzi, but I would need to be able to run at least 2 showers simultaneously, as well as kitchen faucet (and maybe washing machine)... would Noble 199btu be able to handle that?

I was also told that the Noble's 10:1 turndown ratio prevents short-cycling?

hot_rod

With a clean scale free HX the 199 should give you 4.8 gpm at a 77° rise. So to get exact output you would need to know incoming water temperature and the SWT you desire. It's possible the tub has a fill valve that could outrun that, I've seen 15- 20 gpm tub fillers.

The turn down will help as will a few other adjustments for the ramp on that boiler. On mild and low load conditions it will cycle, as most boilers do. Keep an eye on how often and how long it cycles. Ideally at least a 10 minute run overtime it fires.

Although on short quick DHW calls combi boilers will cycle often also. I run mine in the pre-heat mode, the boiler stays warm all the time so DHW is very quick, within seconds. It does cost more fuel$$ and you hear it cycle all day to maintain the fire tube temperature. Try it both ways.

What type of radiation, and how much. If you can run supply temperature around 140 or less some or all of the year, you will leverage the condensing efficiency. That and the benefits of a Combi with a small footprint, no combustion air openings make it a desirable option.

A load calc and survey of the heat emitters could answer these questions.

I like the Nobel out of all the choices i

bob eck

Lochinvar now has an Noble heat only condensing gas boiler. You could use that with an Lochinvar indirect water heater (or another brand indirect water heater)
Store the water at 150 or 160 degrees F and use an mixing valve to get it down to 120 degree F.
If you install the Noble combi boiler 199,000 BTU input you can derate the heating side of the combi boiler to match the house BTU load for heating and when you need domestic hot water the Lochinvar Noble combi boiler will still fire at 199,000 BTU input for your hot water needs.