Thermo Products GMC-85, OMC-70 service manual OMC/GMC Troubleshooting Flowchart

Page 33

All installations and services must be performed by qualified service personnel.

OMC/GMC TROUBLESHOOTING FLOWCHART

Set thermostat subbase to "HEAT"

Does thermostat make contact?

 

 

No

 

 

 

 

 

 

 

 

 

 

 

Is room temperature

 

Yes

 

 

Wait for room air to cool.

 

above 90 deg. F?

 

 

 

 

Yes

No

Yes

 

Is room temperature above

Turn thermostat setting

thermostat setting?

 

above room temp.

No

Replace thermostat

Does a "call for heat" initiate an ignition cycle?

Yes

No

 

 

 

 

Yes

 

 

 

 

Is the power switch "off"?

 

 

Turn power

 

 

 

 

 

 

 

 

 

 

switch "on".

 

 

 

 

 

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

 

 

 

Check input power. Reset circiut

 

Is there 120 VAC

 

 

 

 

breaker, or replace blown fuse in

 

across lines L1 & L2?

 

 

 

 

 

disconnected switch.

 

 

 

 

 

 

 

Yes

 

 

 

Wait for furnace to cool.

 

 

 

 

Is the control transformer

No

Have either of the

Yes

Look for cause(s) of high

limit activation,eg. low

(GMC) or oil primary control

 

high limit thermostats

 

 

 

airflow, over-firing,

(OMC) receiving 120 VAC?

 

activated?

 

 

 

blocked flue,etc..

 

 

 

 

 

 

 

 

Correct any

 

 

 

 

abnormal conditions.

Yes

 

No

 

 

 

 

With power on,measure

 

 

 

voltage across the aux.

 

 

 

high limit thermostat N.C.

 

 

 

contact to L2. If not 120 VAC,

 

 

 

replace aux. high limit

 

 

 

 

thermostat. Else,replace

 

 

 

high limit thermostat.

 

 

32

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Contents GAS-FIRED or OIL-FIRED Furnace Do not RUN the OIL Pump DRY for More than Five Minutes Safety SectionPage Page Page Power Switch Table of Contents Section Beginning Page Models OMC/GMC OMC-70 GMC-85 III. Furnace Specifications ModelBlower Data Burner DataIV. Installation Roof Jack Standard ChimneyFurnace Location Page Base Installation Page Page Closet Installation Alcove InstallationCombustion AIR Page Page Fuel Piping Page Page Electrical Wiring AWG Page Wiring Diagram Burner Installation Burner Operation and Adjustment Page Burner Combustion Parameters Flue GAS Combustion AnalysisPage OMC/GMC Troubleshooting Flowchart If not, replace 1 TDR. On Module GMC or ignition transformer OMC Yes Does the burner stay Yes CAD Cell Checkout Procedure OMC only Heat Exchanger Cleaning Instructions Cleaning or Replacing Flue Pipes On Shut Down Extended ShutdownVI. User Information Section Inspection Areas Component LocationsFilter Location and Cleaning Appendix A. Replacement Parts List

GMC-85, OMC-70 specifications

Thermo Products has built a reputation for delivering top-notch heating and cooling solutions, and the GMC-85 and OMC-70 models are no exception. These high-efficiency gas furnaces are designed to meet the diverse needs of homeowners while prioritizing energy savings and comfort.

The GMC-85 model is known for its impressive efficiency ratings, operating at an AFUE (Annual Fuel Utilization Efficiency) of up to 85%. This means that a significant portion of the fuel consumed is converted into usable heat, making it an economically sensible option for heating your home. Additionally, it features a multi-speed blower motor, which allows for better air circulation and consistent heating throughout the living space. This model also includes a durable heat exchanger crafted from high-quality materials, ensuring longevity and reliability in performance.

On the other hand, the OMC-70 furnace offers a slightly lower AFUE rating of 70%, but it shines in certain areas such as cost-effectiveness and straightforward installation. Its reputation for reliability is bolstered by its rugged design and construction that can withstand the rigors of various climates. The OMC-70 also includes a standard efficiency motor, contributing to reduced energy consumption while delivering appropriate heating requirements for smaller spaces.

Both models utilize advanced technology aimed at improving user convenience and efficiency. Features such as electronic ignition systems enhance reliability by eliminating the need for a pilot light, while also providing a quick and efficient startup process. Furthermore, each unit can be easily integrated with smart thermostats, allowing homeowners to manage their heating needs remotely for optimized performance.

Noise reduction is another characteristic that sets these models apart. Both the GMC-85 and OMC-70 employ sound-dampening technologies to ensure quieter operation, providing a peaceful environment for families.

In summary, Thermo Products' GMC-85 and OMC-70 furnaces present excellent options for homeowners looking to achieve comfort and energy efficiency. With their durable construction, advanced technology, and features geared toward enhancing user experience, these models provide reliable heating solutions suitable for various needs and budgets. Investing in either of these products translates to improved energy savings and consistent warmth, making them popular choices in today's competitive market.