Commercial Tankless Water Heater
Indoor and Outdoor Models Available
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| Expandable Tankless Platform For Commercial Hot Water Systems |
![]() Direct Vent Model |
The UMC-117 Main Controller is used to set temperatures, display error codes and access maintenance information on a single unit installation.
In multi-unit systems, one Main Controller is used as the temperature controller and error display for the entire system. Others continue to be used to display diagnostic information on specific units.
One Main Controller is included with each unit.
The Main Controller can set temperatures between 100° to 180° F.
| SYSTEM SIZE | PEAK OUTPUT GALLONS PER MINUTE | HOURLY OUTPUT GALLONS PER HOUR | ||||
| (number of units) | 45 degree rise | 70 degree rise | 100 degree rise | 45 degree rise | 70 degree rise | 100 degree rise |
| 1 | 7.4 gpm | 4.8 gpm | 3.4 gpm | 444 gallons | 288 gallons | 204 gallons |
| 2 | 14.8 | 9.6 | 6.8 | 888 | 576 | 408 |
| 3 | 22.2 | 14.4 | 10.2 | 1,332 | 864 | 612 |
| 4 | 29.6 | 19.2 | 13.6 | 1,776 | 1,152 | 816 |
| 5 | 37 | 24 | 17 | 2,220 | 1,440 | 1,020 |
| 6 | 44.4 | 28.8 | 20.4 | 2,664 | 1,728 | 1,224 |
| 7 | 51.8 | 33.6 | 23.8 | 3,108 | 2,016 | 1,428 |
| 8 | 59.2 | 38.4 | 27.2 | 3,552 | 2,304 | 1,632 |
| 9 | 66.6 | 43.2 | 30.6 | 3,996 | 2,592 | 1,836 |
| 10 | 74 | 48 | 34 | 4,440 | 2,880 | 2,040 |
| 11 | 81.4 | 52.8 | 37.4 | 4,884 | 3,168 | 2,244 |
| 12 | 88.8 | 57.6 | 40.8 | 5,328 | 3,456 | 2,448 |
| 13 | 96.2 | 62.4 | 44.2 | 5,772 | 3,744 | 2,652 |
| 14 | 103.6 | 67.2 | 47.6 | 6,216 | 4,032 | 2,856 |
| 15 | 111 | 72 | 51 | 6,660 | 4,320 | 3,060 |
| 16 | 118.4 | 76.8 | 54.4 | 7,104 | 4,608 | 3,264 |
| 17 | 125.8 | 81.6 | 57.8 | 7,548 | 4,896 | 3,468 |
| 18 | 133.2 | 86.4 | 61.2 | 7,992 | 5,184 | 3,672 |
| 19 | 140.6 | 91.2 | 64.6 | 8,436 | 5,472 | 3,876 |
| 20 | 148 | 96 | 68 | 8,880 | 5,760 | 4,080 |
This Guide provides a quick reference to the hot water output of a system built on the 28C platform. It can help you size a system based on peak requirements in Gallons Per Minute or Gallons Per Hour.
Example 1 (see system size 4 units above): You are designing a hot water system for a shower room with six showers with 2.5 GPM flow rates, or a total system peak demand of 15 GPM. Inlet temperature in the winter is 40° F, and showering temperature is 104° F, for a rise of 64 degrees. The table shows that at a 70 degree rise, the first system above 15 GPM provides a full 19.2 GPM. Look left and see that this system consists of four 28-C units.
Example 2 (see system size 10 units above): A similar storage-based system you previously designed could deliver 2,000 gallons of 140° F hot water at maximum output. Now you want to get an initial feel for the sizing of a Paloma 28-C system that could be used instead. In your part of the country, you know that winter temperatures will require almost a 100 degree rise in water temperature to reach 140° F. So you find the Hourly Output of 2,000 Gallons in the column for 100 degree temperature rise. Then you move left to the System Size column, and read that a 10-unit system is a good starting point in the design process.
| INDOOR Models | OUTDOOR Models | |
| Natural Gas Model Name | PH-28 CIFSN | PH-28 COFN |
| LP Gas Model Name | PH-28 CIFSP | PH 28 COFP |
| Vent Size | 4" Category III stainless venting with Paloma stainless steel vent adapter or equivalent | N/A |
| Vent Length Maximum | 37.5 ft. with 3 -elbows | N/A |
| Safety Engineering | Oxygen Depletion Safety Systems | N/A |
| Heat Exchanger Film Wrap Overheat Limiter | ||
| Flame Failure Safety Monitor: Flame Rod Type | ||
| Anti-boil protection | ||
| Rated Gas Input (BTU/hr.) | 19,000 - 199,900 (modulating) | |
| Dimensions (Inches) | 14-7/8 (w) x 25-3/8 (H) x 11-1/8 (D) | |
| Net Weight (lbs.) | 55 | |
| Working Water Pressure | 14 - 150 psi | |
| Minimum Flow for Ignition | 0.66 GPM | |
| Maximum Output | 7.4 GPM | |
| Temperature Range | 100 - 180 F (with controller) | |
| Gas Connection | 3/4" NPT Female (Gas shutoff valve included) | |
| Water Connection | 3/4" NPT Male | |
| Efficiency Rating | 84% | |
| Energy Factor (DOE) | 0.82 | |
| Electrical Requirement | 120 V/60Hz AC, 2 Amps | |
| Freeze Protection | Minus 30° F (including windchil factor) | |
| Controller/Diagnostic Display | UMC- 117 (included) | |
| Multi-Unit System Controller (sold separately) | 2-6 unit system: MIC 180 (includes installation box) | |
| 7-20 unit system: MI C-180 + MI CS-180 | ||
The above file is available as a PDF (Portable Document Format) file. If you need to download Acrobat Reader, please click on the link below.
The optional MIC-180 Manifold Controller is used to electronically control operations in a multi-unit system of 2 to 20 units. The MIC-180 Controller Kit includes the control logic for a base system with 2-6 units, a power cord, and an installation box suitable for outdoors.
For larger systems, add a MILS-180 Extended Communication Board, which will fit in the top half of the Installation Box.
The controller connects to the individual units using Paloma communications cables in 16, 32 and 65 foot lengths.
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