Amtrol HM-41Z, HM-41L, HM-80L, HM-80Z User Manual

INSTALLATION & OPERATION INSTRUCTIONS

HYDROMAX

INDIRECT-FIRED WATER HEATERS

1400 Division Road, West Warwick, RI 02893 T: 401.884.6300 F: 401.885.2567 www.amtrol.com

PLEASE READ THE FOLLOWING INSTRUCTIONS CAREFULLY

INSTALLER: LEAVE THIS MANUAL WITH THE OWNER

™

Models Covered:

HM-41Z & HM-80Z (Mechanical Control)

HM-41L & HM-80L (Ener-G-NET™ Digital Control)

IMPORTANT GENERAL SAFETY INFORMATION - ADDITIONAL SPECIFIC SAFETY ALERTS APPEAR IN THE
FOLLOWING INSTRUCTIONS.

DO NOT LIFT OR CARRY WATER HEATER BY THE TOP COVER. WATER HEATER DAMAGE OR PERSONAL
INJURY MAY OCCUR IF THE COVER BECOMES DETACHED.

READ CAREFULLY THE PRODUCT INSTALLATION, OPERATING AND MAINTENANCE MANUAL. FAILURE

INJURY AND/OR PROPERTY DAMAGE, AND WILL VOID THE PRODUCT WARRANTY. THIS PRODUCT MUST BE INSTALLED
BY A QUALIFIED PROFESSIONAL. FOLLOW ALL APPLICABLE LOCAL AND STATE CODES AND REGULATIONS. IN THE
ABSENCE OF SUCH CODES, FOLLOW THE CURRENT EDITIONS OF THE NATIONAL PLUMBING CODE AND NATIONAL
ELECTRIC CODE, AS APPLICABLE.

THIS IS THE SAFETY ALERT SYMBOL. IT IS USED TO ALERT YOU TO POTENTIAL PERSONAL INJURY AND OTHER
HAZARDS. OBEY ALL SAFETY MESSAGES THAT FOLLOW THIS SYMBOL TO REDUCE THE RISK OF PERSONAL
INJURY AS WELL AS PROPERTY DAMAGE.

medium must be limited to 30 PSIG by an approved safety or relief valve.

9040-694 (10/11)

TO FOLLOW THE INSTRUCTIONS AND WARNINGS IN THE MANUAL MAY RESULT IN SERIOUS OR FATAL

The heat transfer medium must be water or other nontoxic fluid having a toxicity rating or class of 1, as
listed in Clinical Toxicology of Commercial Products, 5th edition. The pressure of the heat transfer

1. Table Of Contents

2. Pre-Installation Checklist ...............................................

3. Required Components and Accessories Checklist .......

4. HYDROMAX™ Plumbing ...............................................

5. Ener-G-NET™ Wiring ..................................................

6. Ener-G-NET™ Setup & Adjustment ...............................

2

3

4

5-6

7

2. Pre-Installation Checklist

IMPORTANT STEPS AND DECISIONS REQUIRED BEFORE INSTALLATION

❑ THIS PRODUCT MUST BE INSTALLED AND MAINTAINED

BY A LICENSED PROFESSIONAL PLUMBER, ELECTRICIAN,
AS APPLICABLE. IN ADDITION TO THE INSTRUCTIONS
IN THIS MANUAL, FOLLOW ALL APPLICABLE LOCAL
AND STATE CODES INCLUDING MA CMR 248 OR IN THE
ABSENCE OF SUCH CODES, THE CURRENT EDITIONS OF
THE NATIONAL PLUMBING CODE AND THE NATIONAL
ELECTRIC CODE.

❑ DRIP PAN AND DRAIN: This appliance should not be

installed in an area where leakage of the tank or connections
can result in damage to the area adjacent to the appliance
or to lower floors of the structure. When such locations
cannot be avoided, a suitable drain pan, adequately drained
and kept clear, must be installed under the appliance.

❑ CAUTION: Determine whether your water is corrosive or

acidic, and that there are no suspended solids, toxic or other
substances or abnormally high chlorine levels in the water
that could damage or affect the water heater or the rest of
your plumbing system.

USE GLYCOL ONLY WITH

MODELS.
seepage or leakage of glycol to surfaces where humans or
animals can ingest it, use glycol only in double-walled units,
so that any leaks will most likely be released to the
atmosphere. However, a leak to a surface area may still
occur, so any use of glycol must be monitored closely and
humans and animals should be protected from contact with
the unit.

heating units or elements. Any contaminants in the
baseboard units will contaminate the potable water in the
water heater and also adversely affect its performance.

❑ Wiring Options. Select either a Non-Priority or Priority

System:

Two options are available when wiring the controls of
the water heater in the space heating system (boiler and
distribution elements).

1. Non-Priority System - The controls of the water heater

Glycol is a poisonous substance. To avoid

must be wired as a separate heating zone with a standard
zone valve or a separate circulator dedicated to the water
heater “zone”.

DOUBLE-

Do not connect the water heater
supply with baseboard or other space

WALLED HEAT EXCHANGER

domestic

7. Mechanical Aquastat Wiring ..........................................

8. Startup Procedure .........................................................

9. Troubleshooting .............................................................

10. General Safety Information .........................................

8

9

9

10

11. Replacement Parts ...................................................... 11

NOTICE: In this non-priority option, the water heater will be

supplied just as another zone. This means that if all space
heating zones call for hot boiler water at the same time, the
water heater may not be supplied with enough hot boiler water
to “recover” adequately. The delivery of domestic hot water will
be diminished. In many, but not all cases, this is not a problem
because the routine oversizing of boiler output is adequate for
both loads.

2. Priority System - Under this wiring option the water heater

will be supplied before space heating.

In limited circumstances, space

priority mode. Any demand for space heating is postponed
until the water heater has reached its set temperature. This
delay in supplying the space heating zones is usually not
noticed by the inhabitants of the living spaces. However, in
the event of certain malfunctions such as circulator or
thermostat failure, space heating could be delayed
indefinitely. If undetected and uncorrected, freezing damage
to piping could result.

❑ Select Circulator versus Zone Valve

The flow of hot boiler water to the water heater

controlled with either a motorized zone valve or a circulator.

1. Separate circulator. The recommended way to provide

adequate flow through the water heater heat exchanger is
to use a separate dedicated circulator. This option may be
used even though the heating system utilizes zone valves.

2. Zone valve If a zone valve is to be used, a flow rate of 3

to 5 gpm with all zones in use is required. A full-port zone
valve should be used.

❑ All installations require a low-water cut-off or automatic fill valve on

your boiler system to reduce the risk of boiler water loss.

❑ Steam boiler installations require a low-water cut-off which is also

required by most codes.

❑ Installation of a vacuum breaker is required to prevent damage to

the water heater when drained. There must be no valves installed
between the vacuum breaker and water heater.

heating can be lost in the home in this

can be

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3. Required Components And
Accessories Checklist

THERMAL

EXPANSION

TANK

MODEL

CIRCULATOR

PERFORMANCE

ZONE VALVE

SHUTOFF

VALVES

RELIEF VALVE

HM-41 5 GPM @ 7 FT 3/4” Full Port 4 Included 2.0 Gallon

HM-80 5 GPM @ 7 FT 3/4” Full Port 4 Included 4.4 Gallon

If a steel hydropneumatic tank is in place, replace it with a properly sized diaphragm

expansion tank. Otherwise, significant heat transfer problems can occur by causing air to
be trapped in the heat exchanger. If the boiler system has an existing expansion tank and the boiler temperatures
are being changed, resize the existing diaphragm expansion tank.

Use care when using a torch near the top cover and heat exchanger plate. It is recommended

that the front half be removed prior to soldering to avoid potential damage.

HYDROMAX™ Components 2 Piece Cover Removal and Installation

Boiler Return

Boiler Supply

Cold Water

Inlet

Retaining Screws (2)

Heat Exchanger Pressure Loss

15

10

5

Head Loss (Feet)

0

0 2 4 6 8

Flow (Gallons Per Minute)

Hot Water

Outlet

Heat Trap

Removing Front Half:
Depress both tab buttons to
detach one side at a time.

Installing Front Half:
Align bottom groove of cover
onto metal retaining ring.
Beginning with one side,
align pin and push until both
tabs lock. Repeat for other
side, ensuring all tabs are
fully engaged.

Removing Entire Cover:
Remove front half, loosen
both retaining screws and
remove rear half.

Tab Buttons (4)

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4. HYDROMAX™ Plumbing

DOMESTIC WATER PIPING

1. Connect the cold water supply to the pipe labeled

COLD WATER.

2. Connect the HOT WATER piping to the domestic hot

water system.

3. When all domestic water piping is complete, open the cold water

supply and allow some water to enter the tank. Look and listen
for signs of leaks and repair as necessary before continuing.

Note: If installing on a city supply, a properly sized thermal expansion
tank is required and should be installed in accordance with the
product installation manual.
Note: If a water heater is installed in a closed water supply system,
such as one having a back-flow preventer in the cold water supply,
means shall be provided to control thermal expansion. Contact
the water supplier or local plumbing inspector on how to control
this situation.
Note: If an external electrical source is utilized, the appliance, when
installed,must be electrically grounded in accordance with local
codes or, in the absence of local codes, with the National Electrical
Code, ANSI/NFPA 70.
Note: The thermostat is adjusted to 120° F, when shipped from
the factory.

4. Install the blowdown tube on the T&P relief valve outlet.

Plumb to within 6 inches above a floor drain or as directed by
plumbing code.

Do not drill, puncture or otherwise
penetrate the steel outer tank shell.

Do not screw pipe hangers or other hardware into the
exterior of the tank.

BOILER PIPING

1. Plumb the circulator or zone valve on the BOILER

SUPPLY line.

2. Pipe the BOILER RETURN connection to the boiler return line.

Be sure the return line is NOT

heating circulators. This may require moving the heating
circulator off the boiler tapping on packaged boilers.
Failure to do so will result in overheating and tank
damage when the heating system is in operation.

3. Install a weighted flow check on the boiler return line. This is

not necessary on systems utilizing a zone valve to control the
water heater temperature.

4. After completing the boiler piping, slowly open the boiler fill

valve and pressurize the water heater loop. Check for leaks
and repair as necessary. Proceed to the appropriate wiring
section in this manual.

than 15 psig). An explosion could occur.

plumbed to the suction side of any

EXPLOSION HAZARD. Do not install to

a high pressure steam boiler (greater

Clearance From Combustible Surfaces

LEFT SIDE ........... 1"

RIGHT SIDE.......... 1"

TOP ................9"

BLOWDOWN

REAR ...............1"

FLOOR .............. 0"

FRONT .............. 1"

WIRING AND AQUASTAT

TUBE

COLD WATER

SUPPLY

ON FRONT CAP HALF

BOILER SUPPLY

HOT WATER

OUTLET

BOILER RETURN

TEMPERATURE
SENSOR WELL

TOP VIEW

FROM FRONT

Recommended Clearance for Servicing

LEFT............... 12"

RIGHT ............. 12"

HEAD ROOM .......36"

REAR ..............1"

FRONT ............. 30"

PIPING USING ZONE VALVE

REAR VIEW

(FOR CLARITY)

DRAIN

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