Mr. Heater MHU 125, Operating Instructions And Owner'S Manual, Page: 17 / 67

(2.49
11"WC
Compact Unit / Utility Heater Operating Instructions and Owner’s Manual
17
Section 3 RATING TAG CONVERSION
Figure 3
Figure 4
INLET PRESSURES:
Natural Gas
MAX - 14"WC (3.49kPa)
MIN - 5"WC (1.25 kPa)
Propane
MAX - 14" WC (3.49 kPa)
MIN -
(2.74 kPa)
Step 13
Connect main electrical power, and turn main gas supply back on.
Turn up thermostat to call for heat. When the main burners light
using soapy water check all connections thoroughly for gas leaks.
Remembering to also check the pressure test plug replaced in step
12. Allow the heater to operate for at least 5 minutes, then observe
the main burner flame. A hard blue flame extending into the
tube is normal. Slight yellow tipping is acceptable. There is no air
adjustment to the burner.
Step 14
See figure 3. Remove the data tag for their respective gases. Remove
label and place over the existing portion of the tag. This tag is
preprinted with all the correct information for the converted heater.
Step 15
Remove the converted information tag from the kit and fill in the
information. Then place this tag below the updated rating tag on
the unit.
Step 16
Replace any panels and operate heater following all warnings/
cautions and instructions in the operator’s manual and labels.
Table 4
NATURAL GAS MANIFOLD PRESSURES - IN. W.C.. (KPA)
MHU 50/80/125
ALTITUDE FT. (M)
0-2000
(0-610)
2000-4500
(610-1370)
50/80/125 4.0”WC (0.99 KPA)* 3.6”WC (0.89 KPA)
* NO ADJUSTMENT REQUIRED
TABLE 5
LP/PROPANE GAS MANIFOLD PRESSURES - IN.W.C.. (KPA)
MHU 50/80/125
ALTITUDE FT. (M)
0-2000
(0-610)
2000-4500
(610-1370)
50/80/125
10”WC KPA)* 8.5”WC (2.12KPA)
*NO ADJUSTMENT REQUIRED
Figure 5 & Figure 6