Mr. Heater mh25 Manuale Utente

E4

Installation instructions and Owner’s Manual

Model #  MH25NG/LP 

HS25NG/LP

•  Your heater comes fully assembled and is tested 

at the factory with the appropriate type of gas 

and at the input pressures stated on the name-

plate.

•  Upon receipt and prior to attempting installation, 

be sure to inspect the heater and its packaging 

for damage and/or missing components. If dam-

age is found or missing components are sus-

pected, contact your dealer. See Chapter 5 for a 

complete listing of items required for the safe and 

efficient installation and use of this heater.

•  Never attempt to operate the heater using a 

fuel other than that specifically identified on the 

nameplate.

•  The installation of the heater must conform with 

all local building codes or, in absence of gov-

erning local codes, with the National Fuel Gas 

Code, ANSI Z223.1 (NFPA 54). This code can 

be obtained from either the: Canadian Standards  

Association, 8501 East Pleasant Valley Road, 

Cleveland, OH 44131; or, NFPA, Battery March 

Park, Quincy, MA 02269.

•  Canadian installations must comply with CAN/

CGA-B149.1.2 gas code which can be purchased 

from Canadian Gas Association, 55 Scarsdale 

Road, Don Mills, Ontario M3B 2R3.

•  Contact factory when appliance is to be installed 

at high altitudes. Factory can supply high altitude 

conversion kit with instructions and data plate.

•  A plugged 1/8” N.P.T. Test Gage Connection is 

provided on the heater gas control.

• 

 WARNING: Improper installation, adjustment, al-

teration, service or maintenance can cause property 

damage, injury or death. Read the installation, opera-

tion, and maintenance instructions thoroughly before 

installing or servicing this equipment.  For assistance 

or additional information consult a qualified installer, 

service agency, or gas supplier. 

•

For additional information contact Mr. Heater Toll-

Free 800-251-0001—www.mrheater.com

The following extra NFPA Manuals are helpful when 

installing this heater in a location not anticipated in this 

manual:

 

NFPA 88 

Clearances to Combustible Surfaces

NFPA 409  Clearances to Combustible Surfaces

Provide adequate clearance to combustibles per Table 3 

at control end of heater for servicing and minimum on top 

and sides for ventilation and combustion air supply.
A minimum clearance of 8’ above floor for public garages 

in accordance with NFPA No. 88 most recent edition, or 

Figure 1; whichever is larger.
Canadian installations in public garages must comply with 

CGA 149B.1.9 most recent edition.

 WARNING: Maintain clearances as shown in Figure 2 

or on heater nameplate.

MODEL 

 

BTU/HR. RATING  

 

GAS SUPPLY PRESSURE (W.C.)   

ORIFICE

NO. 

 

GAS 

 

MIN. 

 

MAX. 

MANIFOLD 

SIZE 

 

 

 

NATURAL 

PROPANE 

NAT.    L.P. 

NAT. 

L.P. 

NAT. 

L.P. 

NAT. 

L.P. 

MH/HS25NG  25,000 

— 

7.0” 

— 

14” 

— 

6” 

— 

45 

—

MH/HS25LP  — 

22,000 

—  

11” 

— 

14” 

— 

10” 

— 

55

 

 

MODEL 

OPERATING 

 

ORIFICE SIZE 

INPUT 

 

 

SIZE

NO. 

PRESSURE 

BURNER 

PILOT 

BTU/H 

WIDTH 

LENGTH   

HEIGHT  WEIGHT

MH/HS25NG  6.0”w.c. 

 

  45 

.018 

25.000 

12-1/4” 

29-3/4” 

 

  7” 

  20 lb.

MH/HS25LP 

10”w.c. 

 

  55 

.011 

22,000 

12-1/4” 

29-3/4” 

 

  7” 

  20 lb.