Aqua-Hot 400 Series Service Manual

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Service manual (106 pages)

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400

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AHE-400-P02

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Page 1 Service Manual Series AHE-400-P02...
Page 2: Table Of Contents
Aqua-Hot Maintenance ..............71 Fan Validation Switch Relay..........55 Air Adjustment Procedure ............72 Buck Boosts ................56 Winterizing the Aqua-Hot ............73 Flame Sensor ............... 58 Fenwal Burner Controller ............. 59 Filling the Aqua-Hot ..............74 Propane Burner Schematic ..........60 Purging/Draining the Aqua-Hot ..........
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 Aqua-Hot’s boiler tank to be reheated before being sent by the Aqua-Hot, it must have an adequate fuel supply, receive back through the loop again. This process continues until the...
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 Specifi Cations
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® 400P 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 8 Figure 7 p.
Page 8: Operational Flow Chart
Heat exchanger fans activate, transferring 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® 400P 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: Measuring Antifreeze With Refractometer
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® 400P Service Manual...
Page 12: Interior Switch Controls
The interior switch panel is used to control the two potential to be brought to operating temperature by the electric heating heating sources for the Aqua-Hot’s boiler tank. When a switch is element in approximately 1 to 2 hours. The electric element, activated, the indicator light on the switch will illuminate.
Page 13 Propane Burner JUMPER WIRE Switch Wire Harness Switch Wire Harness J9-2 J1-1 J1-2 J9-3 Chassis Ground J7-3 Chassis Ground NOTE: The Electric Element switch possesses jumper wires that advance from terminal 4 to terminal 10. p. 12 ©Aqua-Hot® 400P 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 2. Open the unit drain valve located on the bottom left of the coolant inside of the Aqua-Hot boiler tank. This allows for very heater, and allow approximately two gallons to drain from granular control of the unit to deliver precise heating and hot the unit.
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
Aqua-Hot’s boiler tank. mark. 4. Install the replacement high-limit thermostat into the port • Verify that all in-line fuses are functional. on the Aqua-Hot’s boiler tank and ﬁ nger tighten only (15 • Ensure that the unit is completely cool. in-lbs). •...
Page 20 4. Install the replacement high-limit thermostat into the port • Ensure that the unit is completely cool. on the Aqua-Hot’s boiler tank and ﬁ nger tighten only (15 in-lbs). • Ensure that DC electrical power is supplied to the Aqua-Hot.
Page 21: Low-Temperature Cutoff Thermostat
1. Ensure that the Aqua-Hot has been completely shut down and that all the power sources have been disconnected. 2. Locate the low-temperature cutoff thermostat on the cold domestic water inlet pipe at the back of the Aqua-Hot (see Figure 28). Figure 26 3.
Page 22: Check Valves
Figure 30 • 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 23: Tempering Valve
10. Slide the hose back onto the replacement pump and set Tempering Valve 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 35 Figure 34...
Page 24: Circulation Pumps
11. 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. 12. Reconnect the motor home’s water lines to the tempering valve assembly.
Page 25 Replacement Procedure depend on which pump is faulty - refer to the schematic on page 76). 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 26: Stir Pump/Circulation Pump 2
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 27 Interlock Switch Stir Pump 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 28: Ac Electric Element
• If the boiler tank is above 158°F, the Aqua-Hot is at NOTE: For continuous domestic hot water, the propane 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
The following conditions must be met before the electric heating element can be diagnosed, and if necessary, replaced. 1. Ensure that the Aqua-Hot has been completely shut down • The ﬂ uid expansion bottle is ﬁ lled to at least the “COLD”...
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: Propane Burner
The Aqua-Hot’s propane burner is a device that ignites a mixture of propane gas and air within a controlled setting to serve as a heat source. 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 and interior heat.
Page 36 Interlock Switch Propane Burner Buck Boost Figure 74 Hot Surface Igniter Buck Boost Combustion Blower Fan Buck Boost Figure 75 Burner Controller Figure 76 ©Aqua-Hot® 400P Service Manual p. 35...
Page 37: Propane Burner Operation
The Combustion Blower there is still a need for Valve is deactivated. Fan is activated for 15 heat. seconds. NOTE: If the Aqua-Hot’s coolant temperature is approximately A 2-Minute Purge The Propane Burner Controller 190°F or higher, the Motor cycle starts.
Page 38 Interlock Switch Propane Burner Figure 77 Part Number Description ELX-375-030 Hot Surface Igniter ELX-375-035 Exhaust Back Pressure Switch PLX-375-045 Dual Stage Gas Valve SME-375-025 Air Intake Shutter ELX-375-020 Combustion Fan Blower ELX-375-015 Flame Sensor ©Aqua-Hot® 400P Service Manual p. 37...
Page 39 Interlock Switch Propane Burner Figure 78 Part Number Description ELX-375-010 Fan Validation Switch ELX-375-015 Flame Sensor PBX-375-010 Mixing Tube ELX-375-030 Hot Surface Igniter MSE-375-015 Refractory Insulation p. 38 ©Aqua-Hot® 400P Service Manual...
Page 40: Detaching The Propane Burner
Light on the interior switch panel should turn OFF when switch is turned to OFF. Or the burner status should show OFF on the coach interior control panel and the Reporter. Make sure the propane supply is shut off at the valve on the top of the Aqua-Hot.
Page 41 They can be removed by ﬁ rmly pulling on the connections. Figure 83 Step 4: Remove the gas line from the Aqua-Hot Locate the gas valve assembly on the propane burner and the corresponding gas lines.. Gas line...
Page 42 Interlock Switch Step 5: Remove the Propane Burner from the Aqua-Hot The propane burner is secured to the Aqua-Hot with four nuts Carefully lift the propane burner away from the Aqua-Hot. that can be removed by using a ½ inch socket wrench with a wobble extension.
Page 43: Reattaching The Propane Burner
Reattaching the Burner Interlock Switch Reattaching the Propane Burner to the Aqua-Hot Step 1: Replace the Mounting Gasket Clean the old gasket off the combustion chamber and boiler Install the new mounting gaskets and reinstall the combustion tank’s front plate.
Page 44 Using a ” wrench, tighten the nut on the gas line to the gas 11 / 16 assembly. valve assembly to secure the line in place. Gas line connection Gas Valve Assembly Figure 94 ©Aqua-Hot® 400P Service Manual p. 43...
Page 45 Wire #86 connects to the PWR terminal. • Wire #92 connects to the BLO terminal. • Wire #82 connects to the HSI+ terminal. Hot Surface Igniter Buck Boost Combustion Blower Fan Buck Boost Propane Burner Controller Figure 95 Figure 96 p. 44 ©Aqua-Hot® 400P Service Manual...
Page 46 Reattaching the Burner 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 97 NOTE: The access cover must be installed prior to operation as a safety switch (interlock) exists.
Page 47: Propane Burner Components
Propane Burner is detached from the Aqua-Hot. Replacement Procedure: The Aqua-Hot operates on both AC and DC power. Be sure to disconnect the 120 V-AC power supply from the Aqua- Hot prior to servicing. Failure to do so could result in serious personal injury, electrical shock, or even death.
Page 48 ﬂ ame condition. 6. After the Hot Surface Igniter is activated, watch the tip to make sure it gets glowing, red hot. The tip should glow for approximately 10 seconds. Figure 102 ©Aqua-Hot® 400P Service Manual p. 47...
Page 49: Refractory
Refractory if the propane burner “pops” on ignition, or if the propane burner fails to ignite. The Aqua-Hot operates on both AC and DC power. Be sure to disconnect the 120V AC power supply from the Aqua-Hot prior to servicing. Failure to do so could...
Page 50: Dual Stage Propane Gas Valve
3. Once it has been determined that the Propane Burner Controller is sending power to the Dual Stage Propane Gas Valve, verify there is 12V DC at both sides of the Dual Stage Gas Valve. Figure 105 ©Aqua-Hot® 400P Service Manual p. 49...
Page 51 Burner Components Interlock Switch Dual Stage Propane Gas Valve The Aqua-Hot operates on both AC and DC power. Be Be sure to turn OFF the Propane Gas Supply sure to disconnect the 120V AC power supply from Replacement Procedure: at the port on top of the Aqua-Hot prior to the Aqua-Hot prior to servicing.
Page 52: Combustion Blower Fan
Burner Controller. If no voltage is present, replace the Propane Burner Controller. 4. If the Propane Burner Controller is sending power out on wire #92 (green), verify that the left High-Limit thermostat is operating properly. Follow the troubleshooting guide for ©Aqua-Hot® 400P Service Manual p. 51...
Page 53 Burner Components Interlock Switch Combustion Blower Fan Figure 108 Propane Burner Controller Figure 109 Figure 110 Figure 111 p. 52 ©Aqua-Hot® 400P Service Manual...
Page 54: Exhaust High Back Pressure Switch
Exhaust “High Back Pressure” Switch Figure 112 Figure 113 NOTE: Image above shows the High Back Pressure Switch with the Dual Stage Gas Valve and gas lines removed. ©Aqua-Hot® 400P Service Manual p. 53...
Page 55: Fan Validation Switch
○ If there is no continuity with the combustion blower fan running, the fan validation switch is defective and will need to be replaced. Figure 114 p. 54 ©Aqua-Hot® 400P Service Manual...
Page 56: Fan Validation Switch Relay
4. Using a digital voltmeter, check the fan validation switch replacement of the wires on the relay. relay for continuity. 4. Test for proper operation. • If continuity exists when the combustion blower fan is Fan Validation Switch Relay Figure 115 ©Aqua-Hot® 400P Service Manual p. 55...
Page 57: Buck Boosts
Buck Boost Converter at the BLO pin, on the controller. • If the propane burner controller is not sending a power signal to the buck boost converter, replace the propane burner controller. Burner Controller Figure 117 Figure 116 p. 56 ©Aqua-Hot® 400P Service Manual...
Page 58 11V DC - 15V DC, replace the buck boost 3. Verify that the Propane Burner Controller is sending power converter. to the Buck Boost Converter at the HSI pin, on the controller. Figure 118 ©Aqua-Hot® 400P Service Manual p. 57...
Page 59: Flame Sensor
NOTE: A defective ﬂ ame sensor will usually allow the burner to ignite for approximately 2-5 seconds, and then shut down into default mode. Figure 120 Figure 121 p. 58 ©Aqua-Hot® 400P Service Manual...
Page 60: Fenwal Burner Controller
Flame current is the current which passes through the ﬂ ame from the sensor to ground to complete the primary safety circuit. The minimum ﬂ ame current necessary to keep the system from lockout is 0.7 µA micro amps. To Figure 123 ©Aqua-Hot® 400P Service Manual p. 59...
Page 63: Lack Of Heat
Interlock Switch Troubleshooting If there is a Lack of Domestic Hot Water: If one of the Aqua-Hot Heating Zones will not get hot: 1. General Information: 1. General Issues: • The heater is only rated for water ﬂ ow of 1.25 •...
Page 64: Antifreeze Leaking
ﬁ ttings. Figure 126 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 65: 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 66 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 400P 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 ©Aqua-Hot® 400P Service Manual p. 65...
Page 67: Burner Troubleshooting
Verify the connections are not damaged or The Heater is loose. functioning properly. Check the Burner’s VDC Continue • Remove the Aqua-Hot’s Access Control Thermostat/ETS on next • Remove the Aqua- Cover. The Interlock switch will Module for continuity. page Hot’s Access Cover.
Page 68 How much propane is in the Does the Fan vehicle Validation Switch Is there a strong have continuity • Is the Aqua-Hot’s propane shut propane odor at while the blower fan off valve is the OFF position? the exhaust pipe? is running? •...
Page 69 Igniter? power to the Hot Surface Igniter. NOTE: additional troubleshooting • Inspect wiring for information, please contact the Aqua-Hot damage or faulty Replace the Hot Surface Customer Service Department at 574-AIR- connections. Igniter Buck Boost. XCEL (574-247-9235). If the Propane Burner does ignite and ﬂ ames out...
Page 70 If no loose wires are found, replace the Reporter. Is the Flame Sensor functioning properly? Replace the Burner Controller. Replace the Flame Sensor. NOTE: For additional troubleshooting information, please contact the Aqua-Hot Customer Service Department at 574-AIR-XCEL (574-247-9235). ©Aqua-Hot® 400P Service Manual p. 69...
Page 71: Cold Weather Operation
When storing the motor home: not winterizing the Aqua-Hot when not allow the burner to function properly.) freezing temperatures are present will result in serious damage to the Aqua-Hot’s Domestic Water Heating System. Also, be sure to use • Check the Reporter for any faults (see Figure 127).
Page 72: Aqua-Hot Maintenance
The level of the antifreeze and water heating solution within the expansion tank should only be checked when the Aqua-Hot is at maximum operating temperature. If additional antifreeze and water heating solution is required, Annual Maintenance: ﬁ...
Page 73: Air Adjustment Procedure
This will set the gap at approximately 0.275”. 3. While holding the bit in place, tighten the set screw. 4. Remove the drill bit and ensure that the air shutter is secure. Set Screw 0.275” Figure 131 p. 72 ©Aqua-Hot® 400P Service Manual...
Page 74: 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 75: 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 134. 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 76: Purging/Draining The Aqua-Hot
See Figure 137. 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 83: 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 84 Service Manual SERIES Aqua-Hot Heating Systems, LLC 7501 Miller Drive, Frederick, CO 80504 Visit us online at www.aquahot.com Call us at (800) 685-4298 or (303) 651-5500 ©2021 Aqua-Hot Heating Systems, LLC. Printed in the USA...

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