Table 4. Trouble Shooting Chart

Below in chart form are various symptoms of a malfunctioning system, possible defects that will cause these symptoms and suggested corrective measures. The chart assumes that the proper gas pressure is available to the heater and that the lighting procedure is as stated on the plate attached to the heater.

SYMPTOMS

CAUSES

SOLUTIONS

 

 

 

burner light off very slow

partially block pilot orifice

replace

 

pilot out of adjustment

re-adjust pilot

 

 

 

burner light off very slow infra-red

partially blocked burner orifice

replace

color stays dull

 

 

 

 

 

burner flash back

low gas pressure

correct line pressure

(roaring noise during operation

 

or call your gas supplier

and ceramic grid surface will be

 

 

dark)

damaged burner

replace

 

 

 

ceramic grid or burner sooting up

first check for damaged burner

replace if damaged

(when new or after cleaning)

orifice

 

 

if burner orifice is not damaged

replace

 

then check for damaged manifold

 

 

 

 

pilot cannot be ignited

blocked pilot orifice

replace

 

gas cock not in position

gas cock knob must be

 

 

turned to pilot and held

 

 

depressed

 

pilot gas flow adjustment

open and adjust

 

screw may be closed

(see Figure 12)

 

 

 

pilot lights but goes out

defective thermocouple

replace

 

defective control

replace

 

 

 

pilot stays lit but main burner

loose wire or improperly wired

tighten connections, check

will not light

 

wiring diagram

 

defective control

replace

 

blocked burner orifice

clean orifice or replace

 

 

 

failure to ignite

main gas off

open manual valves

 

air in gas line

bleed gas line

 

loose wire connections

tighten wire connections

 

dirty wire connections

clean terminals and secure

 

 

terminals

 

 

 

3. REPLACING THE GAS VALVE UNIT

A.Remove the two gas valve unit wires at the gas control valve labeled “PP”.

B.Unscrew gas valve from gas piping.

C.Reconnect gas valve and unit wires to terminals “PP”. Be sure to leave thermostat wire on one terminal.

should be checked before shutdown and again before the next use.

Dusty, wet or corrosive environment. Since these environments can cause the gas control to deteriorate more rapidly, the system should be checked more often.

The gas control should be replaced if:

A.It does not perform properly on checkout or trouble shooting.

4. FREQUENCY OF OPERATOR CHECKS

B. The gas control knob Is hard to turn or push down, or

Intermittent use. Appliances that are used seasonally

it fails to pop back up when released.

Model # MH25NG/LP

HS25NG/LP

13 Installation instructions and Owner’s Manual

Page 12 Page 14
Page 13
Image 13
Mr. Heater MH25LP / MH25NG Symptoms Causes Solutions, Replacing the GAS Valve Unit, Frequency of Operator Checks
Page 12 Page 14

MH25LP / MH25NG specifications

The Mr. Heater MH25LP and MH25NG portable heaters are designed for anyone looking to efficiently heat small to medium-sized spaces, whether indoors or outdoors. These heaters are known for their reliability and effectiveness, making them popular choices for residential use, outdoor activities, and emergency heating scenarios.

The MH25LP is the propane model, while the MH25NG utilizes natural gas, providing versatility in fuel options to cater to different preferences and availability. Each unit is fitted with essential safety features, including an oxygen depletion sensor and an accidental tip-over shutdown system, ensuring peace of mind during use.

One of the main features of the Mr. Heater MH25 series is its impressive heating capacity. The units can produce up to 25,000 BTU per hour, sufficient for heating spaces up to 600 square feet, making them ideal for workshops, garages, cabins, and various outdoor activities. The adjustable heat settings allow users to customize the temperature to suit their comfort level, maximizing efficiency and reducing fuel consumption.

The design of the MH25 heaters emphasizes user convenience. Both models are lightweight and portable, which allows for easy transportation from one location to another. They come equipped with comfortable carrying handles, enhancing their usability for outdoor events, camping trips, or simply moving from room to room.

Another significant feature of the Mr. Heater MH25 series is the sophisticated combustion technology employed. The heaters utilize a radiant heating system that effectively warms objects and people in the room rather than just the air, leading to faster heating times and a more comfortable environment. Additionally, the units are designed with a sturdy and durable construction that ensures longevity, withstanding the rigors of outdoor use.

The units are also designed to operate quietly, making them an excellent choice for environments where noise levels need to be kept to a minimum, such as in personal workshops or while camping.

Overall, the Mr. Heater MH25LP and MH25NG are powerful, safe, and portable heating solutions that provide reliable warmth and comfort in various settings. Their combination of efficient heating, portable design, and safety features makes them an essential tool for anyone needing reliable heating solutions. Whether for everyday use or special events, these heaters stand out as dependable options to keep warm.
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