Desa DNV25NB, DNV40NB installation manual Troubleshooting, Observed Problem Possible Cause Remedy

Page 15

OWNER’S MANUAL

TROUBLESHOOTING

Note: For additional help, visit DESA International’s technical service web site at www.desatech.com.

Note: All troubleshooting items are listed in order of operation.

WARNING: Turn off and unplug furnace and let cool before servic- ing. Unless you need gas supply for testing, shut off equipment shutoff valve before servicing. Only a qualified service person should service and repair furnace.

OBSERVED PROBLEM

POSSIBLE CAUSE

REMEDY

No heat

1.

Thermostat off

1. Check to be sure thermostat is calling for heat.

 

 

 

 

Wire to thermostat could be off terminal

 

2.

Gas supply

2. Be sure equipment gas valve is in the open posi-

 

 

 

 

tion (level or parallel to gas line)

 

3. Electrical connections and power

3. Be sure all electrical connections are secure

 

4.

Motor

4.

Motor must be operating at top speed before

 

 

 

 

burner will come on. If blower is not operating

 

 

 

 

at top speed, check voltage supply (minimum

 

 

 

 

100 volts A.C.). If voltage supply is okay, check

 

 

 

 

for defective motor

 

5.

Malfunctioning microswitch

5. Be sure the microswitch is sailing in far enough

 

 

 

 

to open the solenoid valve and to energize the

 

 

 

 

ignition control. If the switch is not sailing in,

 

 

 

 

clean any dust or dirt from the actuator pin. Other

 

 

 

 

reasons for the switch not sailing in are

 

 

 

 

A. Insufficient blower speed - Slow motor due to

 

 

 

 

faulty motor or lint and dust accumulation on

 

 

 

 

the blower wheels or restriction of return air to

 

 

 

 

the furnace

 

 

 

 

B. Faulty microswitch - Replace switch if cir-

 

 

 

 

cuit to ignition control is not completed when

 

 

 

 

switch is manually engaged. Switch should

 

 

 

 

also be replaced if blower motor running at

 

 

 

 

top speed fails to engage switch within six or

 

 

 

 

seven seconds. Note: To service switch, com-

 

 

 

 

bustion chamber must be pulled out. Follow

 

 

 

 

steps 1, 2, 3, 9 and 10 on page 8 to remove

 

 

 

 

combustion chamber

 

6.

Gas valve

6.

Within 20 seconds after motor reaches 75% of

 

 

 

 

its r.p.m. and microswitch engages, check the

 

 

 

 

following:

 

 

 

 

A. Voltage at valve - If current is present but

valve is not opening, check wire connections B. If wire connections okay - Replace valve C. No voltage at valve - Check circuit completion

through microswitch and limit switch as well as wiring and wire connections. If no defects are found, see Ignition Failures, page 16

www.desatech.com

Continued

201835

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Contents OWNER’S Operation and Installation Manual DNV25NB DNV40NB For Your SafetyFor Your Safety What to do if YOU Smell GAS Dynavent Safety InformationUnpacking Product FeaturesSpecifications Local CodesLocating Furnace InstallationInstallation Items Check GAS TypeCreating Wall Opening and Mounting Furnace Installing ThermostatInstalling in Normal Frame Wall Installing in Masonry WallRouting Thermostat Cable Locating Thermostat on WallConnecting to GAS Supply Connecting Furnace to Gas Supply at Front of FurnaceMounting the Thermostat to Wall Removing Screws on Lower Flange 40,000 BTU/Hr Model Shown Connecting Furnace to Gas Supply at Rear of FurnaceExample Providing Gas Piping to FurnaceChecking GAS Connections Pressure Testing Gas Supply Piping SystemPerformance Check Pressure Testing Furnace Gas ConnectionsFor Your Safety Read Before Lighting Operating FurnaceOperating Instructions Thermostat Control Operation Inspecting Burner FlameNormal Operating Sequence To Turn OFF GAS To FurnaceCleaning and Maintenance Observed Problem Possible Cause Remedy TroubleshootingIgnition Failures Observed Problem Possible Cause Wire and wire connections at probe Parts Wiring Diagrams ReplacementParts Under Warranty Parts not Under WarrantyWhen Gas Quality Is Bad Service HintsTechnical Service When Gas Pressure Is Too LowCabinet Assembly 25,000 BTU/HR Model Illustrated Parts ListCabinet Assembly 40,000 BTU/HR Model Combustion Chamber Assembly 25,000 BTU/HR Model Combustion Chamber Assembly 40,000 BTU/HR Model Burner Assembly 25,000 BTU/HR Model Burner Assembly 40,000 BTU/HR Model Blower Assembly 25,000 BTU/HR Model Blower Assembly 40,000 BTU/HR Model 201835 International Limited Warranty Dynavent GAS Wall Furnace

DNV25NB, DNV40NB specifications

Desa DNV25NB and DNV40NB are contemporary heating solutions designed to meet the demands of modern residential and commercial spaces. Both models integrate advanced technologies, ensuring efficient performance while promoting sustainability and energy conservation.

The DNV25NB is a compact and versatile unit, making it ideal for small to medium-sized environments. It boasts a nominal heating capacity of 25 kW, providing a reliable source of warmth during colder months. One of its main features is the innovative heat pump technology that extracts energy from the environment, thereby lowering electricity consumption compared to traditional heating systems. The unit is also equipped with advanced inverter technology, which allows it to adjust its output according to the heat demand. This results in reduced energy usage and lower utility bills, making it an economical choice for homeowners or businesses aiming to minimize operational costs.

On the other hand, the DNV40NB is designed for larger spaces, offering a robust heating capacity of 40 kW. This model features a dual-stage compressor that enhances its heating efficiency. This technology ensures quick heating response, allowing it to maintain a consistent indoor temperature even in extreme weather conditions. Furthermore, the DNV40NB incorporates smart control systems that enable users to manage settings through a mobile app, providing convenience and remote monitoring capabilities.

Both models are characterized by their eco-friendly refrigerants, which contribute to reduced greenhouse gas emissions. The units are also designed with user-friendly interfaces featuring digital displays, making operation intuitive. Additional safety features, including over-temperature protection and anti-freeze modes, ensure safe usage while prolonging the lifespan of the units.

In terms of installation, both DNV25NB and DNV40NB are designed for easy integration into existing systems. Their compact design enables flexibility in placement without compromising aesthetics. With their reliable performance, energy efficiency, and user-centric technologies, the Desa DNV25NB and DNV40NB offer compelling solutions for those seeking sustainable heating alternatives. Overall, they represent a forward-thinking approach to climate control, combining performance with environmental responsibility.
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