CleaverBrooks CFC ClearFire User manual

1 Rev. 05-2012
Table of Contents
MODEL CFC FEATURES AND BENEFITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
MODEL CFC PRODUCT OFFERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
DIMENSIONS AND RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
PERFORMANCE DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
ENGINEERING DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
STACK/BREECHING SIZE CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
CB FALCON CONTROLLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
List of Figures
AluFer Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Fireside Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Premix Burner Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Model CFC Heat Flow and Component Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
ClearFire Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Model CFC Dimensional Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Competitive Condensation Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Emissions Data Clearfire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-19
Pressure Drop Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22-25
Condensate Piping Direct To Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Optional Condensate Treatment Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Condensate Piping for Multiple Boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Condensate Treatment Tank for Multiple Boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Gas Piping Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Gas Header Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Model CFC Minimum Room Clearance Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
CFC Seismic Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
No Primary Loop with Domestic Water and 2-Way Divert Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Two Boilers and Three Variable Temperature Zones (No Primary Loop) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Two-Pipe Primary/Secondary Piping with Domestic Hot Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Two-Pipe Primary/Secondary Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
No Primary Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Domestic Water Heating, No Primary Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Domestic Water with On/Off and 3-Way Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Piping ‘Hybrid’ Boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
‘Hybrid’ Boilers with Domestic Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
2 Pipe System, Typical (reverse-return) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Model CFC ClearFire Condensing Boiler

Model CFC ClearFire Commercial Boilers
2 Rev. 05-2012
Zoning with Zone Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Domestic Water with 2 Boilers and 2 Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Two Opening Outside Wall Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Two Opening Ducted Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
One Opening Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Two Opening Engineered Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Optional Direct Vent Combustion Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Horizontal through the wall venting using inside air for combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Horizontal flue through-wall with direct vent combustion intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Inside Air - Vertical Vent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
Vertical Stack with Direct Vent Combustion Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Electrical Connections CFC 500-2500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Electrical Connections CFC 3300 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
CFC Rear Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
CB Falcon pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
List of Tables
U.S. Standard Dimensions Model CFC Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Metric Dimensions Model CFC Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Model CFC Boiler Ratings (Sea Level to 2000 Feet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Altitude Correction for Input Capacity at Various Altitude Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
ClearFire Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 - 15
Noise Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
CFC Flow Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
CFC Flow Rates (Metric) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Model CFC Minimum Over Pressure Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Model CFC Boiler Safety Valve Information @ 125 PSIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Model CFC Boiler Safety Valve Information @ 60 PSIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Model CFC Water Chemistry Requirements in accordance with ABMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Glycol Application Guidelnes - Model CFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Max Firing Rate vs. Glycol Concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
HF Speed Settings vs. Glycol Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Model CFC Maximum Condensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
CFC capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Model CFC Minimum and Maximum Gas Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Model CFC Minimum Required Gas Pressure Altitude Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Stack design (single boiler) using room air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Stack sizing using outside air for combustion (direct vent combustion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Operating Conditions - Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Operating Conditions - Display/Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
CB Falcon burner sequence (Central Heat) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Model CFC ClearFire Commercial Boilers
3 Rev. 05-2012
MODEL CFC FEATURES AND BENEFITS
Compact Firetube
Design The Model CFC boiler is a single pass,
vertical down fired durable firetube
boiler. The internal extended-heating
surface tubes provide very high levels of
performance in a compact space,
offering over 10 square feet of heating
surface per boiler horsepower, providing
many years of trouble free performance.
Advanced
Technology Tubes and tube sheets are constructed from UNS S32101 duplex stainless steel.
Tubes feature AluFer tube inserts for optimal heat transfer.
Advanced
Construction The extended heating surface design provides the ideal solution for the demands of
a condensing boiler and helps to recover virtually all the latent heat of the flue gas.
Each tube consists of an outer stainless steel tube (waterside) and the AluFer
extended surface profile on the flue gas side.
High Efficiency With the extended heating surface tubes the CFC boiler will provide fuel to water
efficiency of up to 99% at low fire and 97% at high fire with 80 degrees F return
water temperature.
Ease of Maintenance The powder coated steel casing is designed for easy removal and re-assembly. As
shown in Figure B5-2, the burner is hinged and is provided with hydraulic pistons
for simple opening for service of the spark electrode, inspection of the burner
cylinder, tubes and tube sheet on Models CFC1000 and larger. (On the CFC500 and
750, the burner is hinged only). A front mounted service platform is provided for
easy access to the burner components and controls.
Figure B5-2. Fireside Access
Quality Construction ISO 9001:2001 certified manufacturing process ensures the highest degree of
manufacturing standards are always followed.
ASME Code construction ensures high quality design, safety, third party inspection,
and reliability, and is stamped accordingly.
Premix Technology The burner utilizes "Premix" technology to mix both gas fuel and combustion air prior
to entering the burner canister, with air "leading" during burner firing transitions.
Figure B5-1. AluFer Inserts

Model CFC ClearFire Commercial Boilers
4 Rev. 05-2012
Combined with a variable speed fan, this technology provides very low emission
levels, exceptionally safe operation, and nearly 100% combustion efficiency.
Full Modulation The variable speed fan provides modulated firing for reduced on/off cycling,
excellent load tracking, and reduced operating costs. The burner does not require
mechanical linkage connections between the fuel input valve and air control.
Instead, the microprocessor control positions the fan speed in accordance with
system demand, and this determines the fuel input without mechanical device
positioning - that is, linkage-less fuel/air ratio control. This eliminates linkage
slippage, minimizes burner maintenance, and provides control repeatability. This is
shown schematically in Figure B5-3.
Figure B5-3. Premix Burner Technology
Designed For
Heating
Applications
The pressure vessel is designed for 125 psig MAWP (Max. Allowable Working
Pressure) and is constructed of durable ASTM Grade Steel and Stainless Steel
materials. Figure B5-4 shows the counter flow heat exchanger design that gives
optimal heat transfer. The design also prevents hot spots, does not require a
minimum flow for thermal shock protection, and does not require a minimum return
water temperature. In fact, the design carries a 20-year thermal shock warranty.
Because of its design characteristics, the Model CFC is well suited for applications
utilizing indoor/outdoor reset controls, radiant floor heating, snow melt systems,
ground source heat pump systems and systems that utilize variable speed
circulating pumps. It may also be employed in standard hot water systems that
require higher heated water at colder outdoor temperatures but then require
minimum temperatures during warmer heating days, realizing fuel efficiency savings
over traditional hot water boilers.
While the design does not lend itself to the direct supply of potable water, a separate
storage tank with an internal heat exchanger can be employed, as the
microprocessor control permits domestic water programming. Therefore, the Model
CFC can service both hydronic heating and domestic water source heating.
Dual Return Two return pipes - high and low temperature - allow condensing performance with
as little as 10% return water at condensing temperature.

Model CFC ClearFire Commercial Boilers
5 Rev. 05-2012
Figure B5-4. Model CFC Heat Flow and Component Orientation
MODEL CFC PRODUCT OFFERING
Information in this section applies to condensing hot water boiler sizes ranging from
500,000 Btu input through 3,300,000 Btu input for operation on Natural Gas or
LP Gas only. Installation is for indoor use only.
Dimensions, ratings, and product information may change to meet current market
requirements and product improvements. Therefore, use this information as a guide.
Combustion Fan and
Premix Gas Valve
Assembly
Control
Panel
“Finned” High
Efficiency AluFer
Tubes
ASME Code
Pressure Vessel
Flue Gas
Outlet
High Temp.
Return
Hot Water
Outlet
Air Vent Connection
Burner
Canister
Low Temp.
Return
Safety Relief Valve

Model CFC ClearFire Commercial Boilers
6 Rev. 05-2012
Standard Equipment Equipment described below is for the standard boiler offering:
1. The Boiler
A. Each boiler size is designed for a Maximum Allowable Working Pressure
(MAWP) of 125 psig (8.6 Bar), constructed in accordance with the ASME
Code Section IV and bear the "H" stamp.
B. The insulated boiler is mounted on a base and powder coated steel casing
provided.
C. A drain valve connection is provided at the front bottom for field piping of a
boiler drain valve, which can be furnished as an option.
2. Boiler Trim and Controls
• The following items are furnished:
• Probe Type Low Water Cutoff control, manual reset.
• Excess Water Temperature Cutoff, manual reset.
• NTC (negative temp. coefficient) sensor for hot water supply temperature.
• NTC sensor for hot water return temperature.
• ASME Safety Relief Valve set @ 125 psig. (8.6 Bar)
• Combination Temperature/Pressure Gauge.
3. Burner Control
A. The CB Falcon is an integrated burner management and modulation control
with a touch-screen display/operator interface. Its functions include the
following:
• Two (2) heating loops with PID load control.
• Burner sequencing with safe start check, pre-purge, direct spark ignition (pilot
ignition CFC-3300), and post purge.
• Electronic ignition.
• Flame Supervision.
• Safety shutdown with time-stamped display of lockout condition.
• Variable speed control of the combustion fan.
• Supervision of low and high gas pressure, air proving, stack back pressure, high
limit, and low water.
• First-out annunciator.
• Real-time data trending.
• (3) pump/auxiliary relay outputs.
• Modbus communication capability.
• Outdoor temperature reset.
• Remote firing rate or setpoint control
• Setback/time-of-day setpoint
• Lead/Lag for up to 8 boilers

Model CFC ClearFire Commercial Boilers
7 Rev. 05-2012
Figure B5-5. ClearFire Control Panel (1500/1800 shown)
4. Forced Draft Burner
A. The burner is a "Pre-mix" design consisting of a unitized venturi, single body
dual safety gas valve, blower, and burner head.
B. Full modulation is accomplished with a variable speed fan for 5:1 turndown
ratio.
C. For near flameless combustion, the burner utilizes a Fecralloy-metal fiber
head.
D. Noise level at maximum firing is less than 70 dBA regardless of boiler size.
E. Operating on Natural Gas, NOx emissions will be less than 20 PPM
regardless of boiler size and the boiler is certified for California and Texas for
Low NOx emissions.
F. As an option, the burner is capable of direct vent combustion.
G. Ignition of the main flame is via direct spark, utilizing high voltage electrodes
and a separate electrode for flame supervision (CFC-3300 uses gas pilot
ignition and UV scanner for flame supervision).
H. To ensure adequate combustion air is present prior to ignition, and to ensure
the fan is operating, a combustion air proving switch is furnished.
I. A High Air Pressure Switch is provided to ensure burner lockout if excessive
back pressure due to a blocked stack occurs.
J. For ease of maintenance and inspection, the burner is furnished with
hydraulic rods and easy opening lockdown nuts, which permit the burner to
swing up (except 500 and 750, which are hinged only). This provides full
access to the burner and electrodes, as well, to the tube sheet and tubes.
5. Burner Gas Train
The standard gas train is equipped in accordance with UL certification and complies
with ASME CSD-1. Each burner gas train includes:
FALCON DISPLAY / OPERATOR INTERFACE DEMAND SWITCH
LWCO RESET

Model CFC ClearFire Commercial Boilers
8 Rev. 05-2012
• Low Gas Pressure Interlock, manual reset.
• High Gas Pressure Interlock, manual reset.
• ASME CSD-1 Test Cocks.
• Downstream manual ball type shutoff cock.
• Single body dual safety shutoff gas valve.
Optional Equipment For option details, contact the local authorized Cleaver-Brooks representative. In
summary, here are some of the options that can be provided with the boiler:
A. Dual gas train for quick and easy fuel switchover.
B. Reusable air filter.
C. Condensate neutralization tank assembly - consists of neutralizing media, filter, and PVC
condensate holding tank with integral drain trap. This assembly can be mounted beneath
the boiler.
D. Outside air intake for direct vent combustion.
E. Outdoor temperature sensor for indoor/outdoor control.
F. Header temperature sensor for multiple boiler Lead/Lag operation.
G. Auxiliary Low Water Control (shipped loose) for field piping by others into the system piping.
H. Alarm Horn for safety shutdown.
I. Relays for output signal for burner on, fuel valve open.
J. Stack Thermometer.
K. Stack temperature limit-sensor.
L. Auto air vent.
M. Boiler drain valve.
DIMENSIONS AND RATINGS
For layout purposes, the overall dimensions for the Model CFC are shown in Table
B5-1 (US Dimensions) and Table B5-2 (Metric Dimensions) including the various
pipe connection sizes for supply and return water, drain, and vent. The performance
ratings for the boiler are shown in Table B5-3.
Altitude Relative to the ratings shown, installation of the boiler above 2000 feet elevation
will result in input capacity reduction. Please refer to Table B5-4 for input ratings of
the boiler at various elevations.
PERFORMANCE DATA
Efficiency The Model CFC is a "full condensing" boiler realizing efficiency gain at variable
operating conditions. It is designed to extract the latent heat of condensation over a
greater range than other designs. This can be seen in Figure B5-7, which depicts
nominal stack temperatures of the boiler versus other designs. The nominal point of
condensation is approximately 132F (55.5 C). The ClearFire, due to its more
efficient heat transfer design and lower stack temperature, is able to capture the
latent heat of condensation over a broader range.
Fuel-to-water efficiency is relative to specific operating conditions. Operating
efficiency will be greater in the "condensing" mode of operation as noted above, yet
with its inherently greater heat transfer surfaces and superior pre-mix burner, the
ClearFire’s efficiency under "traditional" hot water conditions is also outstanding.
Table B5-6 through Table B5-9 show the guaranteed efficiencies at various
operating conditions and firing rates for Natural Gas. It should be noted that the
efficiency is exceptional at high fire and low fire versus other designs where high
efficiency is realized only with low fire or minimal firing rates and low temperature
returns.

Model CFC ClearFire Commercial Boilers
9 Rev. 05-2012
Figure B5-6. Model CFC Dimensional Views
I

Model CFC ClearFire Commercial Boilers
10 Rev. 05-2012
Table B5-1. U.S. Standard Dimensions Model CFC Boiler
ITEM DIMENSIONS (inches) 500 750 1000 1500 1800 2500 3300
A Overall Height 71.8 71.8 75.7 81.6 81.6 82.2 85.0
B Overall Width 32.3 32.3 36.6 43.7 43.7 50.8 61.3
C Overall Depth 48.8 48.8 62.6 65.6 65.6 72.6 86.3
D Width Less Casing 26.8 26.8 31.1 38.2 38.2 45.3 55.5
E Gas Connection to Top of Casing 8.1 8.1 9.5 12.5 10.2 9.4 10.0
F Gas Connection to Floor 63.7 63.7 66.2 69.1 71.4 72.8 75.0
G Side of Casing to Gas Connection 2.3 2.3 4.3 3.4 5.2 4.7 5.1
H Boiler Centerline to Air Inlet Centerline 4.0 4.0 4.0 4.9 7.1 7.1 7.1
I Floor to Bottom of Base 10.3 10.3 10.3 10.3 10.3 10.3 10.3
J Floor to Top of Stack Connection 18.6 18.6 18.1 19.1 19.1 20.9 21.4
K Centerline to Centerline of Stack Stub 15.4 15.4 16.9 21.0 21.0 28.1 35.8
L Rear of Boiler to Centerline of Stack
Stub
5.4 5.4 7.5 8.1 8.1 8.6 10.0
M Front of Boiler to Rear of Casing 38.8 38.8 49.4 49.5 49.5 56.5 67.0
N Control Panel Projection 4.1 4.1 4.1 4.1 4.1 4.1 4.3
O Casing Height 56.2 56.2 60.0 65.4 65.4 65.4 67.0
P Air Vent Line Projection from Rear of
Casing
7.8 7.8 7.3 8.1 8.1 8.7 4.7
Q Floor to Centerline of Lower Return 19.5 19.5 19.6 20.7 21.3 22.4 24.1
R Floor to Centerline of Upper Return 28.2 28.7 30.5 20.3 32.3 33.8 35.5
S Floor to Centerline of Supply Connec-
tion
54.3 54.3 56.2 57.1 56.2 56.2 59.1
T Floor to Centerline of Air Vent 59.9 59.9 62.3 63.1 63.1 63.6 66.4
AA Boiler Adjustment Foot Height 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Height Above Boiler for Burner Service 14.0 14.0 14.0 14.0 14.0 14.0 18.0
CONNECTIONS
U Water Supply/Return, 150# RF Flg 2-1/2" 2-1/2" 2-1/2" 3" 4" 5" 5"
V Boiler Air Vent, NPT 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2"
W Electrical Conduit, left or right 1.6" 1.6" 1.6" 1.6" 1.6" 1.6" 1.6"
X Boiler Drain, NPT 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2"
Y Flue Gas Nominal OD, Left or Right
option
6" 6" 8" 10" 12" 12" 12"
Z Combustion Air Option 4" OR 6" 4" OR 6" 4" OR 6" 6" OR 8" 6" OR 8" 8" 8"
BB Gas Connection, NPT 1" 1" 1" 1-1/2" 1-1/2" 1-1/2" 2"
CC Condensate Drain, FPT 3/4" 3/4" 3/4" 3/4" 3/4" 1" 1"
Relief Valve outlet @ 125 # Setting 1" 1" 1" 1" 1" 1" 1"
Voltage Fan Motor 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 208-240/
3/60
Voltage Control Circuit 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60

Model CFC ClearFire Commercial Boilers
11 Rev. 05-2012
Table B5-2. Metric Dimensions Model CFC Boiler
Boiler Size
ITEM DIMENSIONS (mm) 500 750 1000 1500 1800 2500 3300
A Overall Height 1824 1824 1923 2073 2073 2088 2159
B Overall Width 820 820 930 1110 1110 1290 1557
C Overall Depth 1240 1240 1590 1666 1666 1844 2192
D Width Less Casing 681 681 790 970 970 1151 1410
E Gas Connection to Top of Casing 206 206 241 318 259 239 254
F Gas Connection to Floor 1618 1618 1681 1755 1814 1849 1905
G Side of Casing to Gas Connection 58 58 109 86 132 119 130
H Boiler Centerline to Air Inlet Centerline 102 102 102 124 180 180 180
I Floor to Bottom of Base 262 262 262 262 262 262 262
J Floor to Top of Stack Connection 472 472 460 485 485 531 544
K Centerline to Centerline of Stack Stub 391 391 429 533 533 714 909
L Rear of Boiler to Centerline of Stack Stub 137 137 191 206 206 218 254
M Front of Boiler to Rear of Casing 986 986 1255 1257 1257 1435 1702
N Control Panel Projection 104 104 104 104 104 104 109
O Casing Height 1427 1427 1524 1661 1661 1661 1702
P Air Vent Line Projection from Rear of Casing 198 198 185 206 206 221 119
Q Floor to Centerline of Lower Return 495 495 498 526 541 569 612
R Floor to Centerline of Upper Return 716 729 775 516 820 859 902
S Floor to Centerline of Supply Connection 1379 1379 1427 1450 1427 1427 1501
T Floor to Centerline of Air Vent 1521 1521 1582 1603 1603 1615 1687
AA Boiler Adjustment Foot Height 64 64 64 64 64 64 64
Height Above Boiler for Burner Service 356 356 356 356 356 356 457
CONNECTIONS (inches)
U Water Supply/Return, 150# RF Flg 2-1/2" 2-1/2" 2-1/2" 3" 4" 5" 5"
V Boiler Air Vent, NPT 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2"
W Electrical Conduit, left or right 1.6" 1.6" 1.6" 1.6" 1.6" 1.6" 1.6"
X Boiler Drain, NPT 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2" 1-1/2"
Y Flue Gas Nominal OD, Left or Right option 6" 6" 8" 10" 12" 12" 12"
Z Combustion Air Option 4" 4" OR 6" 4" OR 6" 6" 6" 6" OR 8" 8"
BB Gas Connection, NPT 1 "1 "1 "1-1/2 "1-1/2 "1-1/2 "2"
CC Condensate Drain, FPT 3/4 "3/4 "3/4 "3/4 "3/4 "3/4 "1"
Relief Valve outlet @ 125 # Setting 1 "1 "1 "1 "1 "1 "1"
Voltage Fan Motor 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 208-240/
3/60
Voltage Control Circuit 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60

Model CFC ClearFire Commercial Boilers
12 Rev. 05-2012
Table B5-3. Model CFC Boiler Ratings (Sea Level to 2000 Feet)
Description Units 500 750 1000 1500 1800 2500 3300
Input Max. BTU/Hr. 500,000 750,000 1,000,000 1,500,000 1,800,000 2,500,000 3,300,000
KCAL/Hr. 126,000 189,000 252,000 378,000 453,600 630,000 831,600
Natural Gas (1000 Btu/ft3) FT3/Hr 500 750 1000 1500 1800 2500 3300
Propane (2500 Btu/ft3) FT3/Hr 200 300 400 600 720 1000 1320
Natural Gas M3/Hr 14.2 21.2 28.3 42.5 50.9 70.8 93.4
Propane M3/Hr 5.7 8.5 11.3 17.0 20.4 28.3 37.4
Output at 104/86 F [40/30 C] 100% Firing BTU/Hr. 480,000 720,000 960,000 1,440,000 1,728,000 2,400,000 3,168,000
KCAL/Hr. 120,960 181,440 241,920 362,880 435,456 604,800 798,336
BHP 14.3 21.5 28.7 43.0 51.6 71.7 94.6
KW 141 211 281 422 506 703 928
Output at 176/140 F [80/60 C] 100% Firing BTU/Hr. 435,000 652,500 870,000 1,305,000 1,566,000 2,175,000 2,871,000
KCAL/Hr. 109,620 164,430 219,240 328,860 394,632 548,100 723,492
BHP 13.0 19.5 26.0 39.0 46.8 65.0 85.8
KW 127 191 255 382 459 637 841
MAWP PSI 125 125 125 125 125 125 125
BAR 8.6 8.6 8.6 8.6 8.6 8.6 8.6
Operating Temp., Max. °F 194 194 194 194 194 194 194
°C 90 90 90 90 90 90 90
Water Content Gallons 51 51 90 113 99 126 209
Liters 193 193 341 428 375 477 791
Weight w/o Water Pounds 1,160 1,160 1,795 2,225 2,505 3,640 4,835
Kg 526 526 814 1009 1136 1651 2193
Operating Weight Pounds 1,585 1,585 2,545 3,165 3,325 4,685 6,570
Kg 719 719 1154 1436 1508 2125 2980
Weight, Shipping Pounds 1,210 1,210 1,850 2,300 2,600 3,725 5,000
Kg 549 549 839 1043 1179 1690 2268
Fireside Heating Surface ft2 185 185 307 445 596 937 1,258
m2 17.1 17.2 28.5 41.3 55.4 87.0 117
Standby Heat Loss BTU/Hr 1,206 1,639 1,912 2,459 2,561 3,415 4,620
Watts 353 480 560 720 750 1000 1353
Fan Motor Size Watts 335 335 335 750 1,200 1,200 2,200
Operating Voltage, Fan Volts/Ph/
Hz
115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 208-240/
3/60
Control Circuit Volts/Ph/
Hz
115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60
Current Draw, Fan Amperes 4 4 4 8.5 12 12 6.9
Current Draw Cont. Ckt. Amperes 1.5 1.5 1.5 1.5 2 2 2.3
Condensate Quantity Firing Nat. Gas & operat-
ing @ 104/86 F.
Gal/Hr. 4 5 6.5 10 12 16.5 22
l/Hr. 15 19 25 38 45 62 83
Condensate Value PH 4.5 - 5.5 4.5 - 5.5 4.5 - 5.5 4.5 - 5.5 4.5 - 5.5 4.5 - 5.5 4.5 - 5.5
Flue Gas Mass Flow @ 100% Firing (Natural
Gas)
lb/hr 557 835 1,113 1,670 2,004 2,783 3674
kg/h 253 379 505 758 909 1262 1667
Flue Gas Temp. Oper.
176/140 F [80/60 C]
°F 155 180 160 170 170 160 160
°C 68 82 71 77 77 71 71
Flue Gas Temp. Oper.
104/86 F [40/30 C]
°F 105 125 110 108 108 110 110
°C 41 52 43 42 42 43 43

Model CFC ClearFire Commercial Boilers
13 Rev. 05-2012
Table B5-4. Altitude Correction for Input Capacity at Various Altitude Levels
Natural Gas
700' ASL 2000' 4000' 6000' 8000' 10000'
CFC 3300 3300 kBTU/h 3300 3300 3300 3057 2930
CFC 2500 2500 2418 2245 2083 1930 1850
CFC 1800 1800 1800 1800 1666 1544 1480
CFC 1500 1500 1500 1500 1415 1311 1257
CFC 1000 1000 1000 1000 943 874 838
CFC 750 750 750 750 707 655 628
CFC 500 500 500 490 454 421 404
Ratings assume 35% excess air, 80F combustion air.
Blower speed adjustments should be made to match performance and local conditions accordingly.
For minimum gas supply pressures see Table B5-24. Altitude corrections for supply pressure should be made per Table B5-25.
Natural gas heating value of 1000 BTU/SCF assumed.
LP Gas
700' ASL 2000' 4000' 6000' 8000' 10000'
CFC 3300 3300 kBTU/h 3300 3300 3300 3057 2930
CFC 2500 2500 2500 2339 2169 2010 1927
CFC 1800 1800 1800 1800 1704 1579 1514
CFC 1500 1500 1500 1500 1500 1390 1332
CFC 1000 1000 1000 1000 1000 926 888
CFC 750 750 750 750 750 695 666
CFC 500 500 500 500 481 445 427
Ratings assume 40% excess air, 80F combustion air.
Blower speed adjustments should be made to match performance and local conditions accordingly.
For minimum gas supply pressures see Table B5-24. Altitude corrections for supply pressure should be made per Table B5-25.
LP (propane) gas heating value of 2500 BTU/SCF assumed.

Model CFC ClearFire Commercial Boilers
14 Rev. 05-2012
Figure B5-7. Competitive Condensation Analysis
ClearFire
Efficiencies The Tables below depict the operating efficiencies of each size Model CFC boiler,
including radiation losses. As the Model CFC is a fully condensing boiler, maximum
efficiency is obtained when operating within the condensing mode, utilizing the latent
heat of condensation.
Table B5-5. CFC 500 ClearFire Efficiency
Table B5-6. CFC 750 ClearFire Efficiency
Competitor 1
Competitor 2
Clearfire
Firing Rate
%Return Water Temperature F0(C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 99.0 98.8 97.5 94.8 92.0 88.5 88.0
50 97.4 96.2 95.0 92.2 90.5 88.5 88.0
75 97.0 95.6 93.0 90.5 89.0 88.5 88.0
100 96.0 94.6 92.0 89.0 88.5 88.4 87.9
Firing Rate
%Return Water Temperature F0(C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 98.3 97.1 93.6 91.7 90 88.0 87.5
50 96.5 95.3 91.8 89.9 88.5 88.0 87.5
75 96 94.9 91 89 88 87.5 86.5
100 94 92.7 90.5 88.5 87.8 87.0 86

Model CFC ClearFire Commercial Boilers
15 Rev. 05-2012
Table B5-7. CFC 1000 ClearFire Efficiency
Table B5-8. CFC 1500 ClearFire Efficiency
Table B5-9. CFC 1800 ClearFire Efficiency
Table B5-10. CFC 2500 ClearFire Efficiency
Table B5-11. CFC 3300 ClearFire Efficiency
Firing Rate
%Return Water Temperature F0 (C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 99 97.8 94.3 92.4 90.1 88.5 88
50 98.5 96.5 93.5 90.8 89.5 88.5 87.5
75 97.5 96.2 92.5 89.5 88.3 88 87.3
100 96.5 95.8 91.5 88.9 88 87.5 87
Firing Rate
%Return Water Temperature F0 (C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 99 98 96.2 94 91 88.7 88.2
50 98.2 97.5 94.3 92 90 88.5 88.2
75 98 96.5 92.1 91 89 88.5 88.2
100 97 95.3 91.5 90 88.1 87.8 87.5
Firing Rate
%Return Water Temperature F0 (C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 99 98 96.5 94 91 88.5 88
50 98.3 96 93.8 91 89.8 88.5 87.6
75 98 95 93 89.5 88.9 88.3 87.3
100 97.2 94 91.5 88.9 88 87.5 87
Firing Rate
%Return Water Temperature F0 (C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 99 99 97.5 95 92 88.5 88
50 99 98.5 96 93 91 88.3 88
75 98 97 95 92 89 88 87.5
100 98 97 94 91 88.5 87.6 87
Firing Rate
%Return Water Temperature F0 (C)
68 80 100 120 130 140 160
(20) (27) (38) (49) (55) (60) (72)
20 99 98 95.7 93 90.2 88.5 88
50 98.6 97.5 94.1 92 89.6 88.5 88
75 98 96.5 93.5 91 89.2 88.5 87.9
100 97 95 93.1 89.8 89 88.3 87.8

Model CFC ClearFire Commercial Boilers
16 Rev. 05-2012
Emissions The Model CFC Boiler has been tested by an independent testing lab for Low NOx
certification in California under the requirements of South Coast Air Quality
Management District (SCAQMD) Rule 1146. Meeting the requirements of SCAQMD
also qualifies the boiler for meeting the NOx requirements in the state of Texas.
By means of the Pre-mix burner, the Clearfire boiler provides environmentally
friendly emissions when firing natural gas; emission data are shown in Figure B5-8
through Figure B5-13.
Figure B5-8. Emissions Data Clearfire Model CFC 500

Model CFC ClearFire Commercial Boilers
17 Rev. 05-2012
Figure B5-9. Emissions Data ClearFire Model CFC 750
Figure B5-10. Emissions Data ClearFire Model CFC 1000

Model CFC ClearFire Commercial Boilers
18 Rev. 05-2012
Figure B5-11. Emissions Data ClearFire Model CFC 1500
Figure B5-12. Emissions Data ClearFire Model CFC 1800

Model CFC ClearFire Commercial Boilers
19 Rev. 05-2012
Figure B5-13. Emissions Data ClearFire Model CFC 2500
Figure B5-14. Emissions Data ClearFire Model CFC 3300

Model CFC ClearFire Commercial Boilers
20 Rev. 05-2012
Noise Level The Model CFC is extremely quiet at all operating levels, does not require any sound
level modifications to provide ultra low noise levels, and is virtually vibration free.
Thus, it is very suitable in applications that demand low noise levels.
Table B5-11 shows the noise levels of the Clearfire at various firing rates.
Table B5-11. Noise Level (dBA) measured 3 feet in front of boiler
ENGINEERING DATA
Boiler Information The Model CFC boiler is designed for service in any closed hydronic system and can
be used to augment any hot water system. It can be put into operation as a single
stand-alone unit with 5:1 turndown or in multiple units for larger turndown and
capacity.
Clearfire boilers may be utilized in water heating systems with temperatures from
40F (4.4C) to 195F (90.5C); ideal for ground water source heat pump
applications, etc. Because the Clearfire is a full condensing boiler, low water
temperature (below the dewpoint) restrictions do not apply. In fact, the lower the
return the better the fuel savings.
Variable temperature differentials can be designed to make use of changing outdoor
conditions and thus, the Clearfire is not restricted to a nominal 20F (10 C)
differential. The boiler is designed to withstand thermal stresses with supply and
return temperature differences up to 100F (55C), without the use of a boiler-
circulating pump, blend pump or minimum water flow.
Note: The Clearfire does not require a minimum flow or continuous flow through it during operation.
However, the load imposed on the boiler must be considered when sizing the system flow so that
the flow does not exceed the capacity of the boiler or the demand.
Flow Rates and
Pressure Drops To maintain rated capacity of the boiler, recommended flow rates should not be
exceeded as the flow will remove the heat beyond the capacity of the boiler. Table
B5-12 through Table B5-13 can be used to determine the full boiler output relative
to system temperature drop and the maximum recommended system pump flow.
Knowing the flow rate, the pressure drop through the boiler can be found in Figure
B5-14 through Figure B5-19.
System Operating
Parameters To prevent water flashing to steam within the boiler or system, hot water boilers
must operate with proper over-pressure. System over-pressure requirements are
shown in Table B5-14.
Note: The ASME Code Section IV limits the maximum setting of the excess temperature control to
210F (98.9C) for boilers constructed with stainless steel. This is to ensure that water
temperature will not reach the boiling point (steaming) and therefore, so as not to exceed the
maximum limit of this control and in compliance with the Code, the operating limit of 195F
20% Firing 60% Firing 100% Firing
CFC 500 39 48 60
CFC 750 41 51 62
CFC 1000 43 57 66
CFC 1500 40 50 64
CFC 1800 45 56 66
CFC 2500 45 57 68
CFC 3300 63 73 78