Flo-Direct® Complete Thermal Exchange Gas Fired Water Heater Installation, Operation, and Maintenance Manual Warning: If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death. • Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. • What to do if you smell gas –– Do not try to light any appliance.
Armstrong Contents Transfer Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Storage Tank The Flo-Direct System..............................2 Typical System Specifications . . . . . . . .
Safety Icon Legend If instructions are not followed: — injury or death and property damage are imminent — injury or death and property damage are possible — potential property damage, expensive repairs, and/or voiding the warranty may result Warning: If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death.
The Flo-Direct System Armstrong's Flo-Direct water heaters: � Are designed for industrial applications � Use complete thermal exchange technology � Come in sizes from 1 to 16 million Btu/hr � Heat water up to 185 °F maximum Typical System Heater Transfer Pump Storage Tank Armstrong reserves the right to make design or specification changes without notification.
Flo-Direct water heaters are highly efficient, low maintenance systems. � Complete thermal exchange technology means no fuel is used for warmup or idle time and no energy is lost through conversion or exchange. � Without internal moving parts, there is very little to maintain. � Water conditioning is not required. Flo-Direct systems are highly customizable at both a system and component level. The information in this manual generally uses a 5 million Btu/hr unit and is intended to be typical.
Specifications Heater Materials of Construction Component Material Canister 304 SS (10 ga. ≤ AFD-8000; 3/16 > AFD-8000) Canister gasket WARCO white (food grade buna rubber) Flame tube 304 SS Gas piping Malleable iron with standard yellow finish Water piping Copper with brass or bronze fittings OR welded SS Spray ring 304/316 SS Pall ring 304 SS Operational Specifications Spec English Units SI Units Gas supply pressure 2–6 psig (optimum 4–5.5 psig) 0.14–0.41 bar (optimum 0.28–0.
Dimensions E A C 2 B 1 D Connections* 1 Model Dimensions 2 A B C D Weight E Btu/hr kW mm in. mm in.
Orientation UV scanner Blower Exhaust vent Burner actuator Top Plate Burner Water pressure switch Upper Canister See next page for Fuel Train components Water flow volume adjust valve Disconnect panel Control panel Water inlet valve Gas inlet (behind pipe) Water inlet High temp shut-off switch Lower Canister Level switches Hot water outlet Anchoring tab Drain plug Armstrong International IOM-706 Flo-Direct Water Heater Page 6 of 45 Specifications — Heater
Fuel Train Components Regulated pressure display High gas pressure switch Proof of Closure (POC) switch Low gas pressure switch Dual blocking valves Visual display of valve state (white = closed red = open) Regulator Armstrong International IOM-706 Flo-Direct Water Heater Page 7 of 45 Specifications — Heater
Transfer Pump Assembly Materials of Construction Component Material Piping Type L hard copper/welded 304 OR 316 stainless steel Braided flex hose Stainless steel Pump Stainless steel (TEFC motor) Bypass valve Bronze (110 VAC solenoid/stainless steel motorized butterfly valve) Globe valve Bronze/stainless steel Stand Carbon steel (painted) Dimensions and Operational Specifications Model TP-50 Maximum Flow Rate Inlet Connection Outlet Connection Flow Control Valve Bypass Valve Pump Power
Storage Tank Materials of Construction Component Material Structural layer Fiber-reinforced plastic Structural and liner resin DerakaneTM 441-400 Exterior layer resin Isophthalic polyester Tank finish Gel coat with UV inhibitor Color Gray (AT071) Tank fittings Fiber-reinforced plastic Vent Fiber-reinforced plastic Manhole and cover Fiber-reinforced plastic Manhole cover bolts Stainless steel Manhole gasket EPDM Hold down and lifting lugs Powder-coated carbon steel General Specificati
Orientation Screened vent Water inlet Manway Recirculation return Upper sight glass mount (1" NPT) Float switch mount for heater stop Float switch mount for heater start Thermometer mount Lower sight glass mount (1" NPT) Float switch mount for low water to pump cutoff (if used) Outlet Outlet for immersion heater (2" NPT) Armstrong International IOM-706 Flo-Direct Water Heater Page 10 of 45 Specifications — Storage Tank
Assembly and Installation Unpacking Note: • Obvious damage should be noted on delivery paperwork. Hidden damage must be reported to carrier within ten days. • Cleaning heater using local plant standard is recommended prior to installation. • Storage tanks are typically shipped directly from vendor. Depending on heater size and mode of shipping, one of two scenarios may apply.
4 Remove top plate from lower canister. Attach as shown to keep plate approximately level. Note: Top plates on largest heaters have lifting lugs. 5 Position top plate on top of upper canister with holes aligned. Orient so union in fuel line can be connected. Note: "Gas" and "fuel" are used interchangeably in this document. 6 7 Install all bolts and start nuts. Liberal use of an antisieze compound is strongly recommended. Tighten all bolts using pattern shown or similar.
Installing Small Heaters 1 2 3 4 Place lower canister in final heater position: • On level surface • With adequate clearances • With adequate support for operating weight • With outlet facing transfer pump location • Not near flammable or combustible materials To transfer pump Wipe flange and gasket to remove any dirt or debris and place gasket on flange of canister with holes aligned. 18" (sides and back) Move upper canister into position over lower canister using lift lugs.
7 Snug all bolts using pattern shown or similar. 1 9 5 16 13 3 8 12 11 4 7 14 15 6 8 10 2 Lower onto floor and tighten all bolts using pattern shown or similar. Note: Leakage is normal pending stress relief. Tighten applicable bolts as required when leaks appear. 9 Armstrong recommends anchoring heater in place. 10 Repeat tightening sequence after several hours and after a few days of operation or as leaks occur.
Installing Exhaust Ducting Note: • Roof installation preferred. • Flo-Direct heater is not naturally drafting; exhaust is under slight pressure. • Insulation is not required because exhaust temperature is only a few degrees above incoming water temperature. Cover external termination with rain guard and bird screen. Exterior opening must be at least equal to cross section of exhaust duct. Provide independent support for duct. Do not rest weight on heater.
Installing Intake Air Ducting Note: Do not use manifold connected to other appliances. Do not run heater under negative air pressure. Top must be solid metal. Typical enclosure in sheet metal box with screen. Roof Provide independent support for duct. Do not rest weight on heater. Bird screen required. Using outside air is recommended, especially: • When inside air is not dust free • When inside air is under positive or negative pressure Alternatively, filtration may be used.
Water Connections Warranty is void unless clean, potable water is used. If large pressure swings occur, install pressure regulating valve in inlet water line. Note: Incoming water must not contain any chloride compounds above 100 ppm or salts. These will destroy 304 stainless steel. (Alternative metals are available.) Line from transfer pump must be routed to top of storage tank to prevent backflow. Inlet water pipe must be at least as large as heater's water inlet piping.
Fuel Connection 1 Connect union in line between top plate and upper canister. Note: Local codes may require routing regulator vent outside. 2 Connect gas supply (applicable codes may govern connection type). Provide adequate support. Note: Do not put excess weight on heater connection. Note: If codes require pressure test of fuel line, close ball valve entering fuel train to heater. Failure to do so may damage fuel regulator. 3 With ball valve entering fuel train closed, purge air from fuel line.
Electrical Panels Control Panel Spark generator (120V–6000V) Circuit relay A Hour meter Fuse 2 (3A—PLC) Programmable logic controller (PLC) Veri-Flame control Fuse 1 (5A) Terminal block Control Panel Cover (non-modulating) Armstrong International IOM-706 Flo-Direct Water Heater Page 19 of 45 Control Panel
Disconnect Panel Main fused disconnect Control transformer (3 phase to 120V) Grounding lug Motor fuse blocks Terminal block Grounding lug Motor overloads Motor starters Heater Label Note: This is a sample label. All electrical work must conform to the specifications on this label as found on your heater.
Electrical Connections Note: • Consult wiring schematic provided with your heater for exact details. • Remove all cable ties, bubble wrap, and tape from wiring. Top Plate to Upper Canister Note: Sequence shown is recommended, not required. 5 Reconnect threaded fitting to burner flame sensor port. Modulating burner wiring (may not be present) 4 1 Route blower motor wiring through conduit and into disconnect panel. Reconnect spark rod wire to spark rod in burner.
6 Reconnect water pressure switch wiring on top plate to water pressure switch on upper canister. Upper to Lower Canister Note: Depending on how canister sections were oriented during installation, wires and conduit for these connections may not be the correct length. Rewire if necessary. 1 2 3 RTD wiring for modulating burner (rarely present) Thread high temperature switch wiring into control panel. Reconnect conduit. Connect wires to corresponding number locations in terminal block.
Transfer Pump 1 2 Thread wires into control box and reattach conduit. Connect motor wires to overload terminal below motor starter with wire colors opposite same color on input side. Note: Confirm location by looking for wire #83A connected to coil of starter. 3 4 Connect numbered wires to corresponding terminals on terminal strip. If modulating burner, connect second wire for RTD to control panel. Storage Tank 1 2 3 Install float switches from Armstrong in tank oriented as shown.
Main Power Connection Note: If facility does not have surge and lightning protection, Armstrong recommends both for heater. 1 2 Connect supply voltage to top terminals of main fuse disconnect inside disconnect panel. Manually test each starter ("bump the starter") to check for correct motor rotation, as indicated on motor housing. Note: If rotation is incorrect, change any two phases on input side of applicable starter and recheck.
Operation Description of Operation Very efficient heat exchange keeps exhaust within a few degrees of incoming water temperature. Water is dispersed into upper canister and is broken into ever smaller droplets by passing down through palls. Air and gas combine in burner and enter dry flame tube, which enables complete combustion producing no undesirable gases. System operation is controlled by float switches in remote storage tank (not shown).
Sequence of Operation Note: The description in this section assumes that the heater is in automatic mode — "MANUAL/OFF/AUTO" switch set to "AUTO." If heater is equipped with modulating burner, modulation control must display red “MANUAL” when heater is not running or it may not start. Do not press “MANUAL” on the Powers controller thinking it must match heater's mode! Once heater starts, Powers controller will switch to auto mode automatically.
Pre-Start-Up Checklist Note: This section to be performed by installer. Consult other information, such as schematics, as necessary.
Commissioning Inspecting Installation 1 Confirm all checks in start-up checklist above. 2 Check all field connections in control panels. 3 Identify any additional wiring in panels. 4 Confirm rotation of blower and pump motors. 5 Confirm what fuel is supplied and note label on fuel train. Inspecting Water System Note: Run cold water first to prevent damage in lower canister. 1 Jump valve to bypass automatic control.
2 Press "MANUAL START." Verify input zero on PLC lights. Note: During initial start-up, low gas pressure fault light may come on. Once pressure is established, reset pressure switch. Several attempts to start may be required until fuel enters burner. 3 Verify that output zero on PLC and relay A light. 4 Confirm that Veri-Flame controller has a solid green light. 5 Verify that burner goes to high fire after flame is established and VeriFlame indicates flame.
Periodic Maintenance Maintenance Schedule Note: Periodic maintenance for blower and burner is not shown below. See those IOMs for required maintenance. The Flo-Direct heater is designed to require very little maintenance. The list below is recommended, but only safety items (*) are required. Frequency Task Check output temperature (non-modulated). (To change, adjust water flow valve slowly and in small increments allowing time for change to take effect.
High Temperature Switch Check 1 With heater on but not running, unscrew cover on switch (shown removed below). Caution: Wiring is live! Avoid touching connections! 2 Compress spring to trip switch. 3 Confirm that heater shuts down and high temperature fault light comes on. If not, contact Armstrong. 4 Press reset button and replace cover.
Troubleshooting Troubleshooting Table Note: Turn off power to heater prior to beginning. During troubleshooting, turn it on only when and only for as long as required for specific steps below. Troubleshooting Problem Actuator Fault Flame Safety Fault Low Gas Pressure High Gas Pressure Armstrong International IOM-706 Flo-Direct Water Heater Probable Cause Correction Transitory alarm or to confirm fault Turn "AUTO/OFF/MANUAL" switch to "OFF" then to "AUTO" (or "MANUAL" if using that mode).
Troubleshooting Problem Probable Cause High Temperature Fault Contact Armstrong! Do not operate heater! Tank Full Fault: Pump not keeping up with water production Water Pressure Fault Modulating burner does not enter automatic mode and track set-point ("MANUAL" stays lit after flame is established) Correction Water pressure switch failed and "dry fire" start-up attempted Check water pressure. If correct, replace pressure switch. If not, continue. Nozzles clogged Remove top plate and clean nozzles.
Parts Lists Top Plate Note: Some wiring in this drawing has been removed for clarity. 7 & 8 installed in union 6 7 10 8 5 1 2 3 4 9 12 11 Ref No.
Water Train Ref No.
Control Box Ref No. 1 2 3 4 5 6 Description Part No.
Disconnect Box 1 8 13 2 9 12 11 10 6 5 1 3 7 4 Ref No. Description Part No.
Fuel Train Ref No.
Lower Canister Note: This drawing is a composite. Not all parts are present in every heater configuration. All 4 float switches swing downward Secured to float switches (pumped only) Gravity drain For pumped units only Ref No.
Storage Tank Float switch swings down Float switch swings up Check wiring schematic for float switch orientation Ref No. 1 2 3 4 5 Armstrong International IOM-706 Flo-Direct Water Heater Page 40 of 45 Description Bushing, CPVC 4″ x 1/2″ NPT Float Switch, Polypropylene Thermometer, Back Mount, 4″ Stem Plug, 2″ NPT, 304 SS Plug, 1″ NPT, 304 SS Part No.
Appendix: Modulating Burner Note: information on this page is intended for technical personnel. The standard Flo-Direct uses a powered open, spring-closed actuator. The burner will light on low fire and then go to fully open or the high fire position. The heater’s output is only the full rated BTUs of the Flo-Direct. Sometimes it is necessary to vary this output. To accomplish this task, the burner’s output can be modulated.
Controller: The controller is a Powers 535-1112ABD000 model. This is a fully programmable controller that must be programmed in order to work with the Flo-Direct. These are all pre-programmed and tested before leaving the factory, however, if a replacement controller is installed, the new will have to be programmed as specified in the documentation sent with the FloDirect.
If the button is pushed, then the controller will try to open the burner to track the set point, but since there is no flame, the controller will drive the burner to the fully open position. Then the unit will not light because the burner is not in the starting (low fire) position. To restore the controller to normal, the circuit for the d-out must be opened and reclosed.
Limited Warranty and Remedy Armstrong Hot Water, Inc. ("Armstrong") warrants to the original user of those products supplied by it and used in the service and in the manner for which they are intended, that such products shall be free from defects in material and workmanship for a period of one (1) year from the date of installation, but not longer than 15 months from the date of shipment from the factory [unless a special warranty period applies, as listed below].
Notes Armstrong International IOM-706 Flo-Direct Water Heater Page 45 of 45
