Aqua-Hot 400 Series Service Manual

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Service manual (105 pages)

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Service Manual

400

Series

AHE-450-DE5

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Summary of Contents for Aqua-Hot 400 Series

Page 1 Service Manual Series AHE-450-DE5...
Page 2: Table Of Contents
Fuel Solenoid .................61 Cold Weather Operation ............82 Fuel Pump ................62 Aqua-Hot Maintenance ............. 83 Bearings ................65 Winterizing the Aqua-Hot ............95 Diesel Burner Controller ............68 Troubleshooting ............... 70 Filling the Aqua-Hot ..............96 Black Smoke ................. 70 Purging/Draining the Aqua-Hot ..........97...
Page 3: Introduction
Figure 1 If additional assistance is needed in diagnosing and • DO NOT connect the 12-volt DC power to the Aqua-Hot if the repairing the Aqua-Hot, please contact our Technical Service vehicle requires welding. Department at 574-AIR-XCEL (574-247-9235) from 7:00am to •...
Page 4 In order for the diesel-burner to be considered as a water. This motor-aide feature is part of the engine preheating heating source by the Aqua-Hot, it must have an adequate fuel feature and plumbing system, and requires no action on the supply, receive power from the Reporter, and be selected as a user’s behalf to function.
Page 5: Maintenance Schedule
When the Aqua-Hot is at maximum operating temperature, NOTE: Service parts and accessories are available through the coolant is very hot. If the Aqua-Hot heating system is Aqua-Hot Factory Authorized Service Centers or at www. accessed, scalding by hot vapor or coolant may occur. Before aquahot.com.
Page 6: System Features
Recreation Vehicle Industry Association, 1896 Preston White Drive, Hot, and provides a ready reference to speciﬁ cations, test PO Box 2999, Reston, VA 22090-0999. Call them at (703) 620- standards, and important safety notices. 6003 or visit online at www.rvia.org. ©Aqua-Hot® 450D Service Manual p. 5...
Page 7: Component Cut-Aways
NOTE: The top panel has been made transparent in the view above to aid in the explanation of the heater. DO NOT remove the top panel. Doing so risks irreparable damage to the Aqua-Hot. Only remove the service panels. Figure 7 Figure 8 p.
Page 8: Operational Flow Chart
Aqua-Hot to be re-heated heat into the coach interior The now cooled antifreeze and water solution is recirculated back to the boiler tank of the Aqua-Hot to be reheated. ©Aqua-Hot® 450D Service Manual p. 7...
Page 9: Heating Solution
The following information addresses the necessary usage of a water; suppliers of premixed antifreeze are responsible for the propylene glycol based “boiler “ type antifreeze in the Aqua-Hot. use of high quality (distilled, deionized, or soft) water when Propylene glycol is a safer alternative to the more toxic ethylene preparing their antifreeze for sale.
Page 10 Aqua-Hot from allows the antifreeze to transport the heat providing adequate domestic hot water and interior heating.
Page 11 Refractometer Sight Glass Application of Propylene Glycol Upper Blue Field Poor Poor Good Boundary Line Adjust to 32°F Lower White Field p. 10 ©Aqua-Hot® 450D Service Manual...
Page 12: Interior Switch Controls
The interior switch panel is used to control the two potential the boiler tank if the need arises. A cold boiler tank can expect heating sources for the Aqua-Hot’s boiler tank, as well as to to be brought to operating temperature by the electric heating control the engine preheat feature.
Page 13 Wire Harness J9-1 J9-2 J1-1 J1-4 J1-2 J9-3 Chassis Ground Chassis Ground J7-3 Chassis Ground NOTE: The Engine Preheat and Electric Element switches possess jumper wires that advance from terminal 4 to terminal 10. p. 12 ©Aqua-Hot® 450D Service Manual...
Page 14: Exhaust System
The exhaust must NOT vent in the awning area of the motor without deviation to ensure optimal unit operation. home or near the slide-out areas Because the Aqua-Hot’s exhaust is hot and must be kept away • The exhaust must be able to freely exit away from the...
Page 15: Interlock Switch
If the Aqua-Hot fails to operate, and shows no illuminated lights 3. Remove the defective interlock switch from the Aqua-Hot. or displays, it is possible that the interlock switch is faulty.
Page 16: Fluid Level Sensor
Aqua-Hot for functionality BEFORE replacing the ﬂ uid level sensor. Troubleshoot the ﬂ uid-level sensor if the Reporter has issued a low ﬂ uid level fault and the Aqua-Hot is adequately ﬁ lled. Replacement Procedure: The ﬂ uid-level sensor operates by relaying a continuity signal to the Reporter while it is wet.
Page 17: Ets Module/Control Thermostat
The ETS module precisely measures the temperature of the heater, and allow approximately 2 gallons to drain from the coolant inside of the Aqua-Hot boiler tank. This allows for very unit. granular control of the unit to deliver precise heating and hot 3.
Page 18: Ac High Limit Thermostat
Aqua-Hot’s boiler tank. Troubleshooting Guidelines: 6. Install the replacement high-limit thermostat into the port on the Aqua-Hot’s boiler tank and ﬁ nger tighten only (15 The following conditions must be met before the AC High- in-lbs).
Page 19: Dc High Limit Thermostats
4. Install the replacement high-limit thermostat into the port • Ensure that DC electrical power is supplied to the Aqua-Hot. on the Aqua-Hot’s boiler tank and ﬁ nger tighten only (15 in-lbs). If any of the above conditions are not met, correct them before continuing with troubleshooting.
Page 20: Low-Temperature Cutoff Thermostat
2. Turn on a hot water faucet within the coach. Monitor the Reporter screen. 3. Conﬁ rm the LTCO element displays “HOT WATER”. If it displays “INTERIOR HEAT”, locate the LTCO in the Aqua-Hot cabinet. 4. Using a multimeter, test the LTCO for continuity.
Page 21: Check Valves
Figure 27 • Check the “OUTPUTS TO AQUA-HOT” to ensure the 1. Ensure that the Aqua-Hot has been completely shut down corresponding pump is on. and that all power sources have been disconnected. Be sure the boiler tank has adequately cooled.
Page 22: Tempering Valve
Tempering Valve 10. Slide the hose back onto the replacement pump and set the constant tension clamp back into place. 11. Reﬁ ll the Aqua-Hot’s boiler tank with the antifreeze and water heating solution. Tempering Valve Figure 32 Figure 31...
Page 23: Circulation Pumps
12. Reconnect the PEX tube and ﬁ ttings to the tempering valve Reporter as shown below. and the Aqua-Hot. Be sure to inspect the rubber seals and replace if necessary. 13. Reconnect the motor home’s water lines to the tempering valve assembly.
Page 24 Replacement Procedure depend on which pump is faulty - refer to the schematic on page 98). 1. Ensure that the Aqua-Hot has been completely shut down and that all power sources have been disconnected. Be • If the pump testing is ON and there is not 12V DC power sure the boiler tank has adequately cooled down.
Page 25: Stir Pump/Circulation Pump #3
The stir pump circulates the antifreeze and water heating 6. Release the pump from the mounting bracket by inserting solution within the Aqua-Hot’s boiler tank in order to ensure an AWL between the locking teeth and gently prying the even heating of the solution. To accomplish this, the stir pump locking teeth apart.
Page 26: Engine Preheat Pump
Mounting Tab Figure 47 Replacement Procedure 1. Ensure that the Aqua-Hot has been completely shut down and that all power sources have been disconnected. Be sure the boiler tank has adequately cooled down. 2. Drain the antifreeze and water heating solution from the boiler tank using the drain valve.
Page 27 Reporter will need to be replaced. Replacement Procedure Mounting Bracket 1. Ensure that the Aqua-Hot has been completely shut down and all power sources have been disconnected. Make sure Mounting Tab the heater is adequately cooled.
Page 28: Ac Electric Element
• If the boiler tank is above 158°F, the Aqua-Hot is at NOTE: For continuous domestic hot water, the diesel burner operating temperature and requires no heat.
Page 29 - 9.5 ohms. If not, follow the replacement procedure to replace the element. Replacement Procedure: 1. Ensure that the Aqua-Hot has been completely shut down and that all power sources have been disconnected. Make sure the boiler tank is adequately cooled.
Page 30: Ac Relay
Troubleshooting Guidelines: Replacement Procedure: The following conditions must be met before the electric 1. Ensure that the Aqua-Hot has been completely shut down heating element can be diagnosed, and if necessary, replaced. and all power sources have been disconnected. •...
Page 31: Aqua-Hot Reporter
NOTE: For networked control of the Reporter, Aqua-Hot requires system integrators ensure that individual commands are received and processed. Aqua-Hot requires that commands be repeated or conﬁ rmed so that if a single message were dropped, or if there is a brief network disturbance, the Reporter would get into the correct state as soon as the disruption was removed.
Page 32 Replacement Procedure: 10. Tap the Reporter screen to wake the unit. Select “NEXT”. 1. Ensure that the Aqua-Hot has been completely shut down and that all power sources have been disconnected. 2. Remove the four screws that are securing the Reporter.
Page 33: Reporter Testing & Manual Mode
The Reporter contains ﬁ ve distinct categories of fault conditions pumps, and heat sources until the unit has been reﬁ lled and which will assist in diagnosing and repairing the Aqua-Hot the Reporter has been reset. should problems arise. Low-voltage, over-temperature, and...
Page 34 Interlock Switch Manual Mode This mode can accessed under the test page of the Aqua-Hot Heating Reporter (see below). The heating tab will allow the burner, the burner indicator light, and the electric element to be activated and run for ﬁ ve minutes to test for functionality.
Page 35: Diesel Burner
The ﬂ ame is established in a combustion chamber within the Aqua-Hot’s boiler tank, and the heat from the ﬂ ame is transferred to the antifreeze and water heating solution where it can be used for each system of the Aqua-Hot - domestic hot water, interior heat, and engine preheat.
Page 37 Washer, Star, Protection Housing WPX-436-216 Protection Cap WPX-147-834 Screw, Flange, Blower Housing WPX-425-05A Motor Mounting Plate WPX-432-377 Motor Plate Screw WPX-152-269 Washer, Star, Motor Plate WPX-425-060 Motor, Combustion Air/Fuel Pump 12V DC WPX-350-516 Clutch Half, 6mm p. 36 ©Aqua-Hot® 450D Service Manual...
Page 38 Blower Housing Gap) ) - 0.0mm STOCK 42 (nut) WPX-373-001 Blower, Wheel with Shaft WPX-378-313 Bearing Kit WPX-412-244 O-Ring Blower Casing WPX-225-67A Blower Casing WPX-298-964 Grommet, Blower Casing, Left WPX-299-995 Grommet, Blower Casing, Right ©Aqua-Hot® 450D Service Manual p. 37...
Page 39 5 Nm - 6 Nm (44-53 lb-in) WPX-274-313 Ignition Electrode 6 ± 0.6 Nm WPX-638-78A Flame Sensor WPX-887-71A Photo Disc WPX-453-048 Clip, Retaining, Photo Disc WPX-147-699 Flame Sensor Screw WPX-503-03A Fuel Pump Kit WPX-665-49A High Pressure Fuel Tube p. 38 ©Aqua-Hot® 450D Service Manual...
Page 40 WPX-886-41A Fuel Nozzle, 0.35 GPH tube) WPX-412-198 Manifold, Fuel Nozzle, Brass WPX-277-150 Screw, Plate, Nozzle Stand WPX-102-861 Plate, Manifold WPX-371-289 Gear, Fuel Pump, Nylon WPX-152-390 Snap, Ring, Gear FLX-421-010 Fitting, Hex Union 1.4in Tube ©Aqua-Hot® 450D Service Manual p. 39...
Page 41: Diesel Burner Operation
Fuel Pump, will begin to the preset temperature of operate. • The ETS Module/ approximately 160°F. Control Thermostat, NOTE: If the Aqua-Hot’s coolant which senses temperature is approximately coolant temperature, 190°F or higher, the Motor reaches the preset will not operate. Only when the...
Page 42 Diesel Burner Operation Interlock Switch NOTE: The Motor and Combustion Air Blower will begin to operate only if the ETS Module/Control thermostat is calling for heat. ©Aqua-Hot® 450D Service Manual p. 41...
Page 44 Diesel Burner Operation Interlock Switch NOTE: Whenever the Diesel Burner is switched OFF by the Control Thermostat/ETS Module, it will automatically be reactivated once the Aqua-Hot boiler tank’s coolant reaches the present temperature of approximately 160°F (±5°). ©Aqua-Hot® 450D Service Manual...
Page 45: Detaching The Diesel Burner
Be sure to clamp off the Fuel Supply and Return switch panel to the OFF position and disconnect the diesel lines at the ports on top of the Aqua-Hot prior to burner’s power supply before detaching the diesel burner beginning this replacement procedure.
Page 46 Figure 77 Diesel Burner Figure 76 Controller Step 4: Remove the fuel lines from the Aqua-Hot Using a ” wrench, loosen the nuts securing each fuel line to Locate where the fuel lines on the diesel burner connect to the Aqua-Hot bulkhead ﬁ...
Page 47 Step 5: Remove the Diesel Burner from the Aqua-Hot The diesel burner is secured to the Aqua-Hot with two nuts that can be loosened, and swung out of the way by using a 10mm socket wrench with a 10” long extension.
Page 48: Reattaching The Diesel Burner
Step 1: Reattach the Diesel Burner to the Aqua-Hot The diesel burner is secured to the Aqua-Hot with two eye-bolt nuts that can be swung into place, after the diesel burner has been properly aligned and set in place.
Page 49 Interlock Switch Step 2: Reattach the fuel lines to the Aqua-Hot Align the fuel lines on the diesel burner with the ﬁ ttings on the Aqua-Hot, and using a ” wrench, tighten down both the supply and return fuel ﬁ ttings.
Page 50 Interlock Switch Step 4: Reinstall the Access Cover Reinstall the Aqua-Hot’s access cover and securely tighten the three bolts securing the access cover in place. Figure 90 NOTE: The access cover must be installed prior to operation as a safety switch (interlock) exists.
Page 51: Diesel Burner Components
In order to perform the following procedures, it may necessary to detach the diesel burner head. NOTE: The Aqua-Hot 400 Series is equipped with a 20A Fast Blow Fuse, located on the #20 wire, between the Reporter and diesel burner controller’s B-plug, which is the diesel...
Page 52 9. At approximately 12V DC, the RPM reading should be 4500 RPM’s (±300 RPM). If the motor’s RPM reading is not within these speciﬁ cations, the motor must be replaced. Figure 96 Figure 98 ©Aqua-Hot® 450D Service Manual p. 51...
Page 53 Aqua-Hot. Failure to turn off the burner and disconnect power could result in serious bodily injury. 3. Remove the three Hex-Head screws that secure the motor and ﬂ...
Page 54 Burner Components Interlock Switch Electrode Adjustment Gauge Protection Housing Blower Housing Blower Casing Motor Flange Figure 100 ©Aqua-Hot® 450D Service Manual p. 53...
Page 55: Flame Sensor
C-plug harness wires. 2. Should heavy carbon deposits be present, completely remove the ﬂ ame sensor from the photo disc and clean with brake cleaner. Figure 101 Flame Sensor Blue Wire Green Wire Figure 102 p. 54 ©Aqua-Hot® 450D Service Manual...
Page 56 Green Wire NOTE: This screw is used to fasten the (to Diesel Burner) Flame Sensor to the Photo Disc. Remove when replacing the Flame Sensor. Blue Wire Violet Wire (to Diesel Burner) Figure 104 ©Aqua-Hot® 450D Service Manual p. 55...
Page 57: Ignition Electrodes
Electrode Adjustment Gauge Ignition Electrodes Fuel Nozzle Figure 105 Retaining Clamp Retaining Clamp Bolt Fuel Nozzle Manifold Figure 106 p. 56 ©Aqua-Hot® 450D Service Manual...
Page 58 Tap the punch lightly until 6. Slide the electrode into the photo disc. the retaining clamp returns to proper form. Ignition Electrodes Photo Disc Electrical Insulators Electrode Boots Ignition Cables Figure 107 ©Aqua-Hot® 450D Service Manual p. 57...
Page 59: Ignition Coil
Reporter. Ignition Coil Ignition Cable Brown Black Wire (-) Wire (+) Yellow Wire (+) Brown Wire (-) (to Diesel Burner) (to Diesel Burner) Figure 108 p. 58 ©Aqua-Hot® 450D Service Manual...
Page 60: Fuel Nozzle
Figure 109. 3. Remove both the ignition cables from the ignition electrodes, or connect a jumper wire (with alligator clips) across the metal tips of the electrodes. Fuel Line Supply Fuel Line Return Figure 109 ©Aqua-Hot® 450D Service Manual p. 59...
Page 61 ¼ turn, and then ﬁ rmly re-tighten. This will establish a seated ﬁ t and avoid any leaks. Figure 111 Fuel Nozzle Ignition Electrodes Fuel Nozzle Manifold Hex ⅝” Wrench Figure 110 ¾” Wrench Figure 112 p. 60 ©Aqua-Hot® 450D Service Manual...
Page 62: Fuel Solenoid
Electrical Terminals Fuel Solenoid Ignition Cable Shaft Fuel Solenoid Valve Kit Retaining Clamp Positive Terminal Fuel Solenoid Valve Coil Negative Terminal Photo Disc Lock Nut Fuel Solenoid Valve Assembly Retaining Clip Figure 114 Figure 113 ©Aqua-Hot® 450D Service Manual p. 61...
Page 63: Fuel Pump
• Check the motor home fuel tank for diesel fuel. If the the fuel pump for dirt particles. Clean and/or replace if fuel level is below ¼, the Aqua-Hot diesel burner will necessary. not operate. 3. To adjust the fuel pressure, refer to Page 77 - Fuel pressure •...
Page 64 NOTE: Check the ignition electrodes for proper adjustment prior to reattaching the diesel burner. Photo Disc Fuel Solenoid Fuel Pump Fuel Return Banjo Tube Fuel Supply Banjo Tube Figure 116 ©Aqua-Hot® 450D Service Manual p. 63...
Page 65 Banjo Fuel Tube, Supply Banjo Fuel Tube, Return Mounting Screw, Fuel Pump Washer, Lock, Fuel Pump Fuel Nozzle, 0.35 GPH Fuel Nozzle Manifold, Brass Manifold Plate Screw Manifold Plate Fuel Pump Nylon Gear Snap Ring p. 64 ©Aqua-Hot® 450D Service Manual...
Page 66: Bearings
ﬂ ange to the blower housing. Remove the the cast-aluminum blower casing, motor and ﬂ ange assembly along with the clutch halves. Electrode Adjustment Gauge Protection Housing Blower Housing Blower Casing Motor Flange Figure 118 ©Aqua-Hot® 450D Service Manual p. 65...
Page 67 Failure to follow the Flat correct order and direction of the dished surfaces on the Washer washers will result in a restricted rotation of the combustion air blower. Figure 119 p. 66 ©Aqua-Hot® 450D Service Manual...
Page 68 O-Ring Screws Blower w/ Shaft Dished Surface Washer Dished Flat Retaining Snap Surface Washer Ring Washer Drive Flat Bearing Flat Gear Washer Spacer Washer (Steel) (Thick) Tube Snap Ring Bearing Bearing Kit Figure 120b ©Aqua-Hot® 450D Service Manual p. 67...
Page 69: Diesel Burner Controller
Support at 1 (800) 685-4298 for assistance. Controller B-Plug & C-Plug Reporter Back Side Figure 123 Reporter Display Screen Figure 122 Burner Power (+) Figure 124 p. 68 ©Aqua-Hot® 450D Service Manual...
Page 70 C-7 location. Turn the diesel switch ON and insert the probes of a DC voltmeter into the C-2 (+) 1. Disconnect the Aqua-Hot from any and all power sources. and C-5 (-) locations. If no voltage reading registers on the 2.
Page 71: Troubleshooting
Interlock Switch Troubleshooting If the Aqua-Hot is Producing Black Smoke: 1. Things to check before opening up heater: • Low Voltage - Fire up generator/plug coach into shore power • Damaged or Restricted exhaust pipe - Inspect exhaust pipe for damage 2.
Page 72: White Smoke
Interlock Switch Troubleshooting If the Aqua-Hot is Producing Blue/White Smoke: 1. If the Heater smokes on start up or shut down: • Fuel Solenoid ○ Plunger could be worn out ○ Plastic or metal in the way of the plunger ○...
Page 73: Lack Of Heat
Interlock Switch Troubleshooting If one of the Aqua-Hot Heating Zones will not get hot: 1. General Issues: • Diesel/Electric not operating (coolant is cold) • Heater is not up to operating temperature • Interior Zone Thermostat is not calling for heat •...
Page 74: Lack Of Hot Water
• The diesel burner must be on for continuous hot water - the electric element is for limited, light duty use only. 2. Things to test for with a lack of hot water issue: • Aqua-Hot heater bypassed • Outside water faucet is left on • Washing machine valve defective •...
Page 75: Antifreeze Leaking
Either where the brass ﬁ ttings go into the tank, or at the copper pipe where they go through the brass ﬁ ttings. NOTE: If no leaks are found on the Aqua-Hot, it is possible that there is a leak within the motor home. Check all heat exchangers, connections, and tubing for leaks.
Page 76: Wire Gauge Info
Wire Gauge Information: Because all Aqua-Hot heating systems are designed to operate only when there is an adequate supply of DC (Direct Current) voltage, it is imperative that the proper wire gauge be determined and used for the DC power supply and ground wires.
Page 77 Round up to the closest amp draw listed on the left, then round up to the closest length at the top of the chart. • For example, the 450D heater with six Cozy heat exchangers with the Reporter placed 15 feet from the vehicle’s battery would require an 8-gauge wire. Wire Gauge Chart: p. 76 ©Aqua-Hot® 450D Service Manual...
Page 78: Fuel Pressure
” wrench, remove the steel fuel diesel burner. lines from the diesel burner. Figure 129 3. Using a 13mm and a ” wrench, install the fuel bypass ﬁ ttings onto the diesel burner. Figure 128 ©Aqua-Hot® 450D Service Manual p. 77...
Page 79 Step 3: Install the fuel pressure gauge 1. Using a ⅝” and ¾” wrench, remove the fuel nozzle. Figure 130 2. Using a ⅝” and ¾” wrench, install the fuel pressure gauge. Figure 131 p. 78 ©Aqua-Hot® 450D Service Manual...
Page 80 2. Turn the diesel burner ON, either on the switch panel or the coach control panel. A pressure will register on the fuel pressure gauge once the fuel solenoid opens (after approximately 10-20 seconds). Figure 133 ©Aqua-Hot® 450D Service Manual p. 79...
Page 81 2. Turn the diesel burner ON, either on the switch panel or the coach control panel. A pressure will register on the fuel pressure gauge once the fuel solenoid opens (after approximately 10-20 seconds). Figure 135 p. 80 ©Aqua-Hot® 450D Service Manual...
Page 82 Gauge increase Fuel Pump Pressure Regulator decrease Screw (Adjustment) Figure 136 NOTE: If the fuel pressure cannot be adjusted, refer to the fuel pump section on Page 62 for more information and troubleshooting instructions. ©Aqua-Hot® 450D Service Manual p. 81...
Page 83: Cold Weather Operation
When storing the motor home: not winterizing the Aqua-Hot when freezing temperatures are present will result in serious damage to • Determine when the last annual service was the Aqua-Hot’s Domestic Water Heating System. Also, be sure to use performed a FDA-Approved “GRAS” rated antifreeze for winterization. •...
Page 84: Aqua-Hot Maintenance
Aqua-Hot is at maximum operating temperature. If additional antifreeze and water heating solution is required, To keep the Aqua-Hot running smoothly, it is recommended to ﬁ ll the expansion tank to the “HOT” level mark. Reference Figure have the diesel burner tuned up annually or after the coach has 140.
Page 85 Burner Maintenance Interlock Switch Aqua-Hot Maintenance Procedure Step 2: Replace the Fuel Filter 1. Locate the fuel ﬁ lter NOTE: Before performing an annual maintenance, it is 2. Using hose pinch off pliers, clamp off both fuel lines recommended to test run the diesel burner. While testing, going to the fuel ﬁ...
Page 86 Interlock Switch Step 2 Be sure to clamp off the fuel supply and return lines at the ports on top of the Aqua-Hot PRIOR to beginning this replacement procedure. Step 4: Remove the Diesel Burner 1. Locate the diesel burner’s controller and disconnect both plugs.
Page 87 2. Once the combustion chamber has been removed, use a long handled wire brush, and brush the heat transfer tabs to loosen soot deposits. Failure to do so will reduce the Aqua-Hot’s heat transfer capabilities. Combustion Chamber Assembly Combustion Chamber...
Page 88 NOTE: It will be necessary to replace the combustion chamber gasket any time the combustion chamber is removed. Step 6: Reinstall the Combustion Chamber 1. Reinstall the Combustion Chamber assembly and the Air Swirler into the Aqua-Hot. Combustion Chamber Assembly Air Swirler...
Page 89 Burner Maintenance Interlock Switch Step 7: Inspect the Diesel Burner 1. Reinstall the Combustion Chamber assembly and the Air Swirler into the Aqua-Hot. Electrodes Flame Sensor Fuel Nozzle Photo Disc Fuel Pump Grommets Figure 156 Inspect the following: 5. Flame Sensor 1.
Page 90 For light dirt, dust, and/or carbon deposits, simply wipe off the ﬂ ame sensor with a soft cloth. • Should heavy carbon deposits be present, completely remove the ﬂ ame sensor from the photo disc and clean with brake cleaner. Electrodes Flame Sensor Figure 157 ©Aqua-Hot® 450D Service Manual p. 89...
Page 91 Figure 158 Figure 159 Be sure to reattach the diesel burner head prior to switching the heater ON. Failure to do so may result in ignition of the diesel burner and serious bodily injury. p. 90 ©Aqua-Hot® 450D Service Manual...
Page 92 Electrode Adjustment Gauge Ignition Electrodes Fuel Nozzle Fuel Nozzle Manifold Figure 160 Electrical Insulators Retaining Clamp Photo Disc Retaining Clamp Bolt Electrode Boots Ignition Cables Figure 161 ©Aqua-Hot® 450D Service Manual p. 91...
Page 93 NOTE: When reinstalling the diesel burner, be careful not to damage the photo disc or bend the electrodes. Also, be careful not to pinch any wires between the burner and the Aqua-Hot boiler tank. 1. Align the diesel burner with the Aqua-Hot, using the alignment tabs welded on the Aqua-Hot.
Page 94 Burner Maintenance Interlock Switch Step 13: Reconnect the Fuel Lines 1. Align the fuel lines on the diesel burner with the ﬁ ttings on the Aqua-Hot. Using a ” wrench, tighten down both the supply and return fuel ﬁ ttings.
Page 95 Burner Maintenance Interlock Switch Step 15: Reinstall the Aqua-Hot’s Access Cover 1. Reinstall the Aqua-Hot’s access cover. NOTE: The access cover must be installed prior to operation as a safety switch (interlock) exists. It will prevent the Aqua- Hot from operating whenever the access cover is not properly installed.
Page 96: Winterizing The Aqua-Hot
The warranty does not cover freeze damage. NOTE: The Aqua-Hot can continue to be used for interior heat De-Winterization once the domestic hot water system has been winterized. 1. Completely drain the fresh water storage tank.
Page 97: Filling The Aqua-Hot
Aqua-Hot. serious injury or death. 3. Open the Aqua-Hot’s drain valve located at the front of the heater. Reference Figure 173. NOTE: The Aqua-Hot’s boiler tank must be ﬁ lled with the antifreeze and water heating solution through the drain valve, not through the top of the unit, to avoid air traps.
Page 98: Purging/Draining The Aqua-Hot
See Figure 173. Purge Procedure: 1. Locate the ﬂ uid expansion tank of the Aqua-Hot. As any air is purged, it will exit through to this expansion tank. 2. Locate a gallon of glycol antifreeze. This will be used to top-off the ﬂ...
Page 105: Warranty
Thus, problems due to improper speciﬁ cations, improper installations, improper use, the use of accessory parts or parts not authorized by Aqua-Hot Heating Systems Inc., repair by unauthorized persons, and damage or abuse of the heater are specially excluded from warranty coverage.
Page 106 Service Manual SERIES Aqua-Hot Heating Systems, LLC 7501 Miller Drive, Frederick, CO 80504 Visit us online at www.aquahot.com Call us at 574-AIR-XCEL (574-247-9235). ©2021 Aqua-Hot Heating Systems, LLC. Printed in the USA...

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