MicroHeat JVIS USA Tankless Electric Water Heaters Instruction Manual

: June 9, 2024
: MicroHeat

MicroHeat JVIS USA Tankless Electric Water Heaters

INTRODUCTION

This installation manual covers the MicroHeat (MH) Series 6 Continuous Flow Electric Water Heater (CFEWH). Units include displays showing output water temperature (settable up to 140°F, temperatures below 120°F are recommended to prevent scalding), and flow rate. Series 6-10 and 6-10HW requires 8 AWG wiring circuits or larger and Series 6-13 and 6-13HW requires 6 AWG wiring circuits or larger. For Hard Water areas it is recommended to use the MH SERIES 6 HW (Hard Water) range. This is where the drinking water source is known to have higher than acceptable mineral/salt content in the water. Also known as poor quality residential water.

SINGLE INSTALLATION (1 unit)

TANDEM INSTALLATION (2 or more units)

BENEFITS OF MH SERIES 6 CFEWH

KEY BENEFITS

DECREASED INFRASTRUCTURE COSTS

Setting the water temperature on the unit below 120°F or less will prevent user scalding, and unless otherwise specified, no tempering valves or thermostatic mixing valves are required.
Point-of-use installation significantly reduces requirement for hot water reticulation infrastructure.

SMALL FOOTPRINT

Facilitates point-of-use installation.
Easy to install.

DECREASED OPERATING COSTS AND MINIMAL WATER WASTAGE

Always operates at “optimum” power.
Switch-on flow rate is as low as 0.39 gal/min.
No requirement to heat water in anticipation of use.
Stable hot water temperatures are delivered.
Reduced water consumption due to reduced draw off.
Hot water reticulation energy losses significantly reduced.
Virtually maintenance-free: no scaling of heating element or element burn out.

COMPARING HOT WATER SERVICE

“OPTIMIZED” ENERGY

Optimized” energy is the capacity to heat water more efficiently – delivering reductions in the consumption of both energy and water.

REDUCED ENERGY CONSUMPTION

Lower flow rate = less water volume to be heated and less energy is consumed.
Minimal temperature adjustment required = less energy is consumed

REDUCED WATER CONSUMPTION

Hot water temperature stability = less water is consumed.
The lower the flow rate = less water is consumed.
Minimal temperature adjustment required = less water is consumed.
Of course, the ideal situation would be for Electric Tankless Water Heating (EIWH) units to have some degree of “optimized” energy – however, most do not incorporate this.
The 100% “optimized” energy delivered by the MH Series 6 results in far less than the full-rated power being consumed.

INSTALLATION OPTIONS

Here are some suggested options for installation. The flexibility of the unit allows custom solutions for your needs, whether point-of-use or multi-point use. Please note that the location and installation of the unit is not limited to the options shown here.
Units can be installed in tandem to double flow rates, if needed. Your needs will depend on your regional climate; refer to our flow tables for specifications.
NOTE: When the unit is connected to a washing machine, dishwasher, etc. with automatic on/off controlled inlet valve and for long pipe runs, a water hammer arrestor must be mounted at the outlet of the unit. This will reduce the water hammer effect during the automatic turning off of the water inlet valve of these appliances.
The unit should be installed in a vertical position on an internal wall, or in an internal cupboard or space.
IMPORTANT: Where the ambient temperatures are likely to approach freezing, i.e., less than 41°F, the unit must be drained of water to prevent frozen water damage from occurring. Failure to comply with the installation and operating instructions, or improper use, voids the warranty.

COMPONENTS AND DIMENSIONS

Chassis
Top Cover
Heat Sink
Flow Rate Sensor
Temperature Sensor, Receptacle, Cable and Plug Assembly
¾ NPT Inlet Water Connection
¾ NPT Outlet Water Connection
Printed Circuit Board Assembly (PCBA) V7.4
Earth Locking Mechanism
Series 6-13 / Series 6-10 Exterior Cover
Exterior Cover Screws x 2: Pan Phillips Head Self-Tapping Screw (included separately in small satchel)
Wall Mounting Screws (NOT INCLUDED)
Inlet Filter
PCBA Terminal Block
Electric Mains Supply Cable Gland
RED/GREEN LED: (GREEN Ready/RED Error)
Flow Rate/Temperature Setting Display
Exterior Cover Plug
Exterior Cover Hole
- THE FOLLOWING ARE NOT SHOWN HERE. SEE PAGE 9.
Display PCBA, Cable and Plug (LED Indicator)
PCBA Reset Button

PCBA = PRINTED CIRCUIT
BOARD ASSEMBLY

SPECIFICATIONS

All specifications, stated operational ﬂow rates, and output water temperatures are valid within the range of water conductivity / resistivity

For standard models (6-10. 6-13):
- › 80μS/cm to 1300μS/cm +15% at 68°F (μS–microSiemens)
- › 1.25kΩ-cm to 7.7kΩ-cm +15% at 68°F
For hard water models (6-10HW. 6-13HW):
- › – 300μS/cm to 3300μS/cm + 15% at 68°F (μS–microSiemens)
- › – 3.3kΩ-cm to 300Ω-cm + 15% at 68°F

SINGLE PHASE — MH SERIES 6

PRE-INSTALLATION CHECKLIST

Please read through this section before commencing installation to ensure you are familiar with all of the component parts and the ﬁtting procedure.

THIS UNIT MUST BE INSTALLED BY

A LICENSED ELECTRICIAN to ensure installation conforms to all current electrical wiring codes and safety standards.
A LICENSED PLUMBER to ensure installation conforms to all current plumbing codes and safety standards.

OTHER SPECIFICATIONS

IP RATING The unit is rated as IP25. The unit must be installed inside a dwelling or construction and should not be exposed to splashing water, rain or any circumstance that will allow water to enter the outside cover.
MAXIMUM RATED OPERATING WATER PRESSURE The maximum operating water pressure is 0.8 MPa / 8 bar / 116 PSI.
AMBIENT TEMPERATURE The unit is intended for internal installation and should not be installed in an environment where there is a possibility of the ambient temperature dropping below 41°F.
WATER RESISTIVITY To ensure optimal operation, the resistivity of the incoming cold water supply should not be less than 1.25kΩ-cm, and should not be greater than 7.7kΩ-cm. If the unit is operated with water resistivities outside of this range, it will not function as specified.

The CFEWH should preferably be installed in a vertical position on an internal wall, or in an internal cupboard or space. If the safety rules or the instructions outlined in this manual are not followed correctly, the unit may not operate properly, and could cause damage to property, serious bodily injury, and/or death. MicroHeat, nor its Distributors, will be liable for any damages due to failure to comply with the installation and operating instructions outlined in this manual or through improper use. Improper use includes the use of this unit to heat any liquid — other than potable water — within the conductivity range speciﬁed in this manual.

INSTALLATION OVERVIEW

STEP 1 ELECTRICAL INSTALLATION BY A LICENSED ELECTRICIAN ONLY The unit is to be connected with fixed wired power (Live 1 and Live 2) and a ground wire (Ground Earth). Once active wires are connected to the unit, the unit must be mounted into position and tested for connectivity.
STEP 2 PLUMBING INSTALLATION BY A LICENSED PLUMBER ONLY The unit hot water outlet is connected to a hot water plumbing fixture, and the cold water inlet is connected to the cold water source. Additional equipment (not included) is required for safety standards, such as pressure limiting valves, shutoff valves, water hammer arrestors, etc., as shown on Page 3.
STEP 3 PREPARATION AND USAGE BY THE CONSUMER The unit is to be flushed, primed, tested, temperature set, and used by the consumer.

Preparation for Use
Optimized Energy Usage
Operating the MH Series 6
Diagnostics and Error Descriptions

ELECTRICAL INSTALLATION

AFTER DIVERSITY MAXIMUM DEMAND

As per National Electrical Code (NEC), the current in a circuit must not exceed the current rating of the circuit protective device and this, in turn, must not exceed the current carrying capacity of the circuit conductors. Necessarily in this context, both Diversity Factor and Demand Factor should be taken into account when calculating the electrical load on the electrical supply.

NATIONAL ELECTRICAL CODE (NEC): ARTICLE 220 BRANCH-CIRCUIT, FEEDER, AND SERVICE LOAD CALCULATIONS 220.1 Scope. This article provides requirements for calculating branchcircuit, feeder, and service loads. Part I provides general requirements for calculation methods. Part II provides calculation methods for branchcircuit loads. Parts III and IV provide calculation methods for feeder and service loads. Part V provides calculation methods for farm loads.

DIVERSITY FACTOR Diversity Factor is the ratio of the sum of the individual maximum demands of the various subdivisions of a system (or part of a system) to the maximum demand of the whole system (or part of the system) under consideration. Diversity is usually more than one. Diversity Factor = sum of total demands ÷ maximum demand on feeder.

DEMAND FACTOR Demand Factor is the ratio of the sum of the maximum demand of a system (or part of a system) to the total connected load on the system (or part of the system) under consideration. Demand Factor is always less than one. Although feeder conductors should have an ampacity sufficient to carry the load, the ampacity needs not always be equal to the total of all loads on connected branch-circuits. A study of the National Electrical Code (NEC) will show that a Demand Factor may be applied to the total load. The Demand Factor permits a feeder ampacity to be less than 100 percent of all the branch- circuit loads connected to it

PRELIMINARY INFORMATION In accordance with the wiring rules, National Electrical Code (NEC), or NFPA 70, the Live / Live / Ground electrical supply connections Live (L1), Live (L2) and Ground (Earth ) (LLG) must be permanently connected to the 14 Terminal Block mounted on the PCBA as shown (see Fig. 1). Electrical connections should be made as instructed, using appropriate UL listed strain relief devices.

IMPORTANT : This unit is classified as a Bare Element Water Heater. The unit must be correctly connected to the mains earth. In order to prevent a hazardous circumstance occurring due to the inadvertent resetting of the thermal cutout, the electrical supply to this unit must not be supplied through an external switching device, such as a timer – nor can it be connected to a circuit that is regularly switched on and off by the electricity supply utility.

TANDEM INSTALLATION

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* With tandem installations, both units must be fitted with their own respective circuit breaker and isolation switch.
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- The unit must be connected to the mains supply with ﬁxed wiring.
- It is recommended that an appropriate mains isolation switch be installed in-line with the fixed wiring electrical supply.
- The unit must be installed on a branch circuit with a protective device rated at 55 Amps. Bring the Live / Live / Ground supply through the 15 Electric Mains Supply Cable Gland (OPTION 1) or through the 19 Exterior Cover Hole (OPTION 2) as shown below.
- Bring the Live / Live / Ground supply through the 15 Electric Mains Supply Cable Gland (OPTION 1) or through the 19 Exterior Cover Hole (OPTION 2) as shown below.

STEPS FOR INSTALLATION

Find a clean, ﬂat surface and place the unit on its back. Using both your thumbs and foreﬁngers, grip the 10 Exterior Cover ﬁrmly along the bottom of the unit, and push the cover slowly up to separate it from the 1 Chassis of the unit.
Carefully remove the 19 Display PCBA/LED Plug and Cable connecting either the Display PCBA or Indicator LED on the outside of the 10 Exterior Cover to the 8 PCBA. Set aside for reconnection during electrical installation.
Ensure the circuit breaker and the isolation switch (if installed) supplying the 220 – 240VAC electrical mains to the unit are turned OFF.
Electricity supply cable installation:
- OPTION 1: cable must be brought through the electric gland, and then the unit can be mounted. The cable enters from the rear of the unit.
- OPTION 2: cable must be brought through the hole in the 10 Exterior Cover, and then the unit can be mounted. The cable enters through the front of the 10 Exterior Cover of the unit. If using this option, an appropriate
- UL listed strain relief device must be used
Mount the unit onto the wall using four 12 Mounting Screws. Reference the SCREW HOLE MOUNTING TEMPLATE (provided separately from this manual, making sure to only mount the unit through the screw hole mounts on the unit to avoid damaging the unit, VOIDING THE WARRANTY.
Carefully replace the plug and cable connecting the 19 Display PCBA/LED Indicator to the 8 PCBA
Switch ON the circuit breaker and isolation switch supplying the electric mains power to the unit and check if the unit is turned ON.
Place the 10 Exterior Cover back onto the unit and use the 11 Exterior Cover Screws to secure it in place.

PLUMBING INSTALLATION

The unit is a closed outlet water heater and is intended to operate at the pressure of the water mains, where the ﬂow of water is controlled by one or more faucets/ valves in the outlet line. The unit can be installed into any type of commercial or residential construction as per the current plumbing standards. However, it is mandatory for a water pressure limiting valve and a shutoff valve to be connected in series with the unit’s 6 Cold Water Inlet Connection

The unit maximum rated operating line pressure is 0.8 MPa / 8 bar / 116 PSI.
The unit minimum operating pressure is atmospheric pressure.
The installation of a pressure limiting valve – a mandatory requirement – ensures that excess water pressure applied, as result of water hammer and/ or other circumstances, does not stress the unit unduly.
The inlet water pressure limiting valve must be rated at 0.5 MPa / 5.0 bar / 72.5 psi.
The shutoff valve installed must not be a non-return type valve.
Inlet and outlet piping must be maximum 3/4, minimum 20 pipe length.
If the unit is supplying a dishwasher/washing machine, a water hammer arrestor must be installed on the outlet side of the unit.

STEPS FOR INSTALLATION

Switch OFF the circuit breaker and isolation switch supplying the electric mains power to the unit for plumbing installation.
Connect the water pressure limiting valve (5.0 bar / 72.5 psi / 500 kpa) and shutoff valve.
Connect the water supply via the shutoff valve and pressure limiting valve to the unit to the 6 Inlet Water Connection. The 6 Inlet and 7 Outlet
Water Connections are both ¾ NPT. NOTE: Flush the cold water line before connecting to the unit.
Connect the hot water from the 7 Outlet Water Connection.
Run water through the unit without power to ensure there are no leaks.
Switch ON the circuit breaker and isolation switch supplying the electric mains power to the unit for plumbing installation

PREPARATION FOR USE

STEP 1: FLUSH

Flushing is required to clear the unit of plumbing debris that may have collected in the piping during installation.
This is done with the electric power supply turned off.
Flush water through the unit.
Flushing should be allowed to continue for one to two minutes.
If there appears to be flow restriction through the unit, check the 13 Inlet Filter for build-up of debris

STEP 2: PRIME

The unit must be primed – this is required only once – priming will happen after initial installation.
(Priming is only required when the electricity supply to the unit has been turned off/removed from the unit – for example, after a power failure or an isolation switch OFF condition.)
Priming is required to set the unit up environmentally to ensure that the heating ramp-up time from start during normal operation will be as short as possible, without incurring power overshoot.
Once primed, the unit will ramp-up to the optimized power required at the time without overshoot.

OPERATING THE MH SERIES 6 CFEWH
The unit will automatically begin operating when you turn on a hot water tap, and water is flowing faster than 0.39 gpm. The heated water temperature can be varied or set manually by using the decrease and increase push buttons. Temperature can be set between a minimum of 68°F and the maximum factory set temperature of 140°F (temperatures below 120°F are recommended to prevent scalding). The display also shows water flow rate in gallons per minute (gpm). The minimum flow rate that can be displayed is 0.01 gpm and the maximum displayed is 9.99 gpm. MicroHeat JVIS USA Tankless Electric Water Heaters
26

MH SERIES 6 CFEWH – 16 LED INDICATOR LIGHT
The 16 LED indicator on the 10 Exterior Cover indicates the operational status of the unit.
LED INDICATOR NOT ILLUMINATED: No electricity is being supplied to the unit.
SLOW FLASHING GREEN: Standby mode, waiting for water to be turned on.
FAST FLASHING GREEN: The unit is operating and water is being heated.
FLASHING RED / THEN GREEN: The unit is self-diagnosing an error that it will attempt to resolve. When the error has been resolved, the LED will return to slow or fast flashing
GREEN. “ERR“ will be shown in the OUTPUT
WATER TEMPERATURE SETTING DISPLAY and the error code (starting with “A“) will be in the FLOW
RATE DISPLAY. See next page for the full list of error codes.
RED CONTINUOUSLY ON:
IRRESOLVABLE / MECHANICAL LOCKOUT ERROR “ERR“ will be shown in the OUTPUT WATER
TEMPERATURE SETTING DISPLAY and the error code (starting with “F“) will be in the FLOW RATE
DISPLAY. See page 16 for full list of error codes.
For any additional service questions, contact our customer service at support@microheat.us.

DIAGNOSTICS AND ERROR DESCRIPTIONS

MicroHeat JVIS USA Tankless Electric
Water Heaters 27

MAINTENANCE

MANUAL INTERVENTION
IMPORTANT: The MANUAL INTERVENTION procedure must only be performed by a licensed professional. An IRRESOLVABLE / MECHANICAL LOCKOUT ERROR may be resolved by resetting the unit by pressing the 20 PCBA RESET Button. This can be done by following these steps:

Remove the 10 Exterior Cover and unplug the connecting cable from the 19 PCBA Plug. The three LED indicators on the PCBA will be illuminated when the unit is in standby, running or in error mode.
Depress the 20 PCBA Reset Button mounted on the 8 PCBA. If the error has been successfully reset, the GREEN LED on the PCBA will start to ﬂash slowly, indicating the unit is now in standby mode.
Reconnect the connecting cable from the 19 PCBA Plug and replace the 10 Exterior Cover

LIMITED WARRANTY FOR MH SERIES 6

LIMITED WARRANTY FOR MICROHEAT TECHNOLOGIES PTY LTD CONTINUOUS FLOW ELECTRIC HOT WATER HEATER (CFEWH) SERIES. For the MicroHeat Technologies Pty Ltd Continuous Flow Electric Water Heater SERIES (“CFEWH”), MicroHeat US will replace the CFEWH, which falls within the Warranty Periods and Territory speciﬁed below, subject to the warranty conditions and the warranty exclusions. Limited Warranty Period within the Territory (United States) is 2 years from the date of purchase by the consumer. You are entitled to a replacement for a major failure. It is the responsibility of the consumer to provide proof of purchase within the Territory.

WARRANTY CONDITIONS

This warranty is applicable only for CFEWH appliances.
The CFEWH must be installed in accordance with the MicroHeat CFEWH Installation Instructions, to be supplied with the CFEWH water heater, and in accordance with all relevant statutory and local requirements of the Country or State in which the CFEWH is installed.
Where a CFEWH is replaced under warranty, the balance of the original warranty period will remain effective. The CFEWH does not carry a new warranty.
Where a CFEWH is replaced under warranty, MicroHeat will provide replacement at its expense. Customer is responsible for return of CFEWH to place of purchase when replacement is permitted under this warranty.
The warranty only applies to the CFEWH and therefore does not cover any plumbing or electrical parts supplied by others and not an integral part of the CFEWH, e.g., pressure limiting valve; tempering valves; isolation valves; shut off valves; electrical switches; electrical cabling; pumps or fuse.
The beneﬁts of this warranty are the sole warranties made by MicroHeat. ALL OTHER WARRANTIES, RIGHTS, AND REMEDIES OF THE CONSUMER ARE EXCLUDED EXCEPT TO THE EXTENT REQUIRED TO BE PROVIDED UNDER APPLICABLE FEDERAL OR STATE LAW. ANY REQUIRED IMPLIED WARRANTIES ARE LIMITED TO A 2 YEAR DURATION.
The CFEWH must be sized to supply the hot water in accordance with the guidelines in the MicroHeat CFEWH literature.

PROCEDURE FOR HONORING WARRANTY
To initiate a claim for a warranty against defects, the consumer shall return product to place of purchase for replacement. For additional product information consumer may contact:

MicroHeat US / JVIS USA LLC
52048 Shelby Pkwy
Shelby Charter Township, MI 48315

WARRANTY EXCLUSIONS

Replacement will be carried out as set out in the MicroHeat warranty. However, the following exclusions may cause the MicroHeat warranty to become void:
Accidental damage to the CFEWH or any component, including: acts of God; failure due to misuse, abuse, ﬁre or ﬂood damage; incorrect installation; damage as the result of transportation, removal or storage; faulty attempts to repair the CFEWH.
Where the complaint is related to circumstances where there is no ﬂow of hot water due to faulty plumbing; where water leaks are related to plumbing and not the CFEWH or CFEWH components; where there is a failure of electricity or water supplies; where the supply of electricity or water does not comply with relevant standards.
Where the CFEWH or CFEWH component has failed directly or indirectly as a result of excessive water pressure in excess of 8 bar; incorrect pressure limiting valves; incorrect tempering valve settings; temperature input in excess of 60ºC /140ºF and/or excessive thermal input; blocked outlet; corrosive atmosphere; foreign matter in the water supply; or ice formation in the pipe work to or from the CFEWH water heater.
Where the CFEWH is located in a position that does not comply with the MicroHeat CFEWH Installation Instructions or relevant statutory requirements.
Replacement of the CFEWH due to the effects of either corrosive water or water with a high chloride or low pH level caused by unnatural circumstances or when the CFEWH has been connected to a water supply with water conductivity levels that are outside the range of water conductivity outlined in the Installation Instruction Manual. This warranty excludes any and all claims for damage to furniture, carpets, walls, foundations, or any other consequential loss either directly or indirectly due to leakage from the water heater, or due to leakage from ﬁttings and/or pipe work of metal, plastic or other materials caused by water temperature, workmanship, or other.

MANUFACTURED BY: