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Choosing a boiler

Redduc97
Redduc97 Member Posts: 15
Does anyone have any experience with Noritz boilers. I was looking at the CB-180 which is a combi unit.
I was also looking at an HTP UFT-80 and an indirect water heater. I'm not sure of the best way to go.

Comments

  • I had a customer request a Noritz combi, but I have no first-hand experience with them. I'd like to know more about them myself.
    Often wrong, never in doubt.
  • BillyO
    BillyO Member Posts: 274
    stay away from HTP, nothing but a headache
  • hot_rod
    hot_rod Member Posts: 14,871
    Redduc97 said:

    Does anyone have any experience with Noritz boilers. I was looking at the CB-180 which is a combi unit.
    I was also looking at an HTP UFT-80 and an indirect water heater. I'm not sure of the best way to go.

    It really comes down to how much hot water you want or need. Even the smallest Combi will produce 2 gpm or more depending on the temperature lift. Most rate them at a 70- 77° lift.

    Combi's usually have a means to derate them when it is in heating mode. I have a Lochinvar Nobel 120 locked at 30% firing for the heat, full output for Nobel as the DHW load needs the 100K firing rate for the endless hw it provides.

    If you have a large tub for example and want a fast fill a tank may be better.

    If you run multiple dhw loads at the same time a tank may be better.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • NoritzAmerica
    NoritzAmerica Member Posts: 1
    Redduc97 said:

    Does anyone have any experience with Noritz boilers. I was looking at the CB-180 which is a combi unit.
    I was also looking at an HTP UFT-80 and an indirect water heater. I'm not sure of the best way to go.

    Hello! Our Noritz CB Series of combination boilers are a great choice if you're looking for hot water and heating for your home:
    - Capable of producing up to 4.5 GPM @ 77°F temperature rise.
    - Come equipped with an integrated Grundfos pump and stainless steel heat exchangers

    Hopefully this helps! To get more information about our CB180, visit our website at https://www.noritz.com/product/cb180/
  • hot_rod
    hot_rod Member Posts: 14,871

    Redduc97 said:

    Does anyone have any experience with Noritz boilers. I was looking at the CB-180 which is a combi unit.
    I was also looking at an HTP UFT-80 and an indirect water heater. I'm not sure of the best way to go.

    Hello! Our Noritz CB Series of combination boilers are a great choice if you're looking for hot water and heating for your home:
    - Capable of producing up to 4.5 GPM @ 77°F temperature rise.
    - Come equipped with an integrated Grundfos pump and stainless steel heat exchangers

    Hopefully this helps! To get more information about our CB180, visit our website at https://www.noritz.com/product/cb180/
    Thanks

    I browsed through the installation manual, it's not clear if it can be down fired, or firing delayed for a small heating side load?
    I see it does have ODR ability.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2
  • Redduc97
    Redduc97 Member Posts: 15
    Does adjusting the max. fire rate help with short cycling when you have small heat zones? I have three zones in a 2400 S.F. colonial with two full baths. Family of four (two teens) , my existing system never worked that well so we never use both showers at the same time. It would be nice if the new system would handle multiple showers.
  • hot_rod
    hot_rod Member Posts: 14,871
    Redduc97 said:

    Does adjusting the max. fire rate help with short cycling when you have small heat zones? I have three zones in a 2400 S.F. colonial with two full baths. Family of four (two teens) , my existing system never worked that well so we never use both showers at the same time. It would be nice if the new system would handle multiple showers.

    Exactly. Really the best first step is a heat load calculation to see what your home needs. As a guess use 2400 sq ft. at 25 BTU/ ft would require 60,000 BTU / hr.
    Knowing that 80% of the heating season you may be below that design condition. So a boiler that could ramp to maximum requirement of 60K and modulate down to the lowest rate would be the best bet are reducing short cycles. Basically with ODR set up you have a boiler with cruise control.

    Next question is the winter time water temperature. If you are on a private well, probably around 50°. public water from their storage and piping can drop to mid 30's. so the output you can expect varies.

    So a 120,000 that could modulate down to 12,000 and be locked at 60,000 would fit the heat load and provide 2.5 gpm or more depending on incoming water temperature.

    If you have common 1.5 gpm shower heads you could run two loads, maybe dishwasher or washer and shower.

    You can put closer numbers to these examples if that helps the decision, your heat load, and incoming water temperature.

    One downside to endless hot water, it's endless :) So long showers= $$ may become a family tradition.

    With a tank you have a storage of dump water and whatever the boiler recovers while using the DHW. There is a limit to what the tank will provide, until it recovers.
    Tanks cost $$, take more space, have standby loss.

    So pros and cons to both options.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2
  • Redduc97
    Redduc97 Member Posts: 15
    Does anyone have any experience with the HTP Elite Ultra boiler?
    I think it is fairly new, not a lot of feedback on it yet.
  • BillyO
    BillyO Member Posts: 274
    installed 5 HTP EFT combi wall hung in last 2 years,
    2 replaced under warranty
    3 bad diverting valves,
    1 cracked heat exchanger
    2 wrong main controls installed at factory
    1 cracked exhaust boot within cabinet
    just my experience with HTP, not to favorable
  • mattmia2
    mattmia2 Member Posts: 3,683
    Your dhw needs will vary a lot based on what the supply water temp is. In Michigan where we have about a 35 degree supply from the utility i can run out my SSU-40 with a UFT-100 and i have checked the uft is firing at 100% when it runs out. in my case if i had 5 people taking showers consecutively or concurrently I would have gone with the ssu-80 to be safe. A significantly larger boiler is also an option but i didn't have the gas supply for that and you then the lowest firing rate may still be much to high for you load on a mild day. if your supply water temp is higher or you can tolerate low flow shower heads you can scale that back a lot.

    Be sure to look at your water quality and the specs of the combi or indirect, stainless steel doesn't like water with high chlorides, combis don't like high cholorides or hard water, especially hard water with a high ph. High chlorides might mean a different brand indirect that is a different stainless alloy or a polymer is your only option.

    @NoritzAmerica is the CB series fire tube or water tube?

    Fire tube boilers have a mass of a gallon or 2 of water in the boiler and can better deal with brief interruptions to circulation from things like unexpected combinations of calls and are less likely to be damaged if something fails and stops circulation.
  • mattmia2
    mattmia2 Member Posts: 3,683
    A combi won't make hot water until it senses flow and has a chance to change modes and fire unless it has a small storage tank or a recirculation pump.
    BillyO
  • ThomasM84
    ThomasM84 Member Posts: 7
    edited March 2020
    I don't have experience with Noritz, but if a high flow rate is what you need, I'd recommend a model like my Rinnai RL94iN. The max flow rate is 9.8 gpm and it's rated at 199000 BTUs max, I've had it for a year now and I'm pleased with it.
    Solid_Fuel_Man
  • BillyO
    BillyO Member Posts: 274
    HTP EFT combi piped with a 40 gallon HTP coil booster. throw a mixing valve off the top of tank. You will never run out of hot water
  • mattmia2
    mattmia2 Member Posts: 3,683
    That depends on your incoming water temp and usage. If you have 35 degree municipal water in the winter like I do, you need a very large boiler to get more than about 1.5-2 gpm 120 degree water.
  • hot_rod
    hot_rod Member Posts: 14,871
    I think most combis and tankless now use a 77° rise for their output sheets. Some still use 70°, so read the fine print.

    So a 77 rise on 35 incoming gets you to 112° plenty for a shower or tub. A 120K input boiler should supply 1.5- 2 gpm at that temperature rise.

    The hydronic formula shows what it takes in BTU/hr

    Q= 500 X flow X delta
    Q= 500 2 (112-35)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2