CETP 4.5 Basic Propane Appliance Service and Troubleshooting

This whole module provides a "big picture" overview of the course, which includes info on service/troubleshooting for ____________________ .

Basic propane appliances (standing pilots)

When necessary, use proper __________________ to make sure no one else turns on the power to the circuit until you have completed the repair.

Lockout/tagout procedure

If the appliance cannot be immediately fixed or the customer chooses to have someone else repair the appliance, then determine whether you are obligated to remove appliance from service and use a _____________ .

Warning tag

The four types of appliance service calls are:

- troubleshoot/repair appliance

- start up/shut down propane appliances

- preventive maintenance

- emergency response calls

____________ are designed for general purpose measurement of air, surface, and gases. Extremely fast response time because of a small exposed tip.

Bead Probes

good examples of using a bead probe is measuring ambient air, and measuring the insides of _______ .

Ovens

What would indicate a defective limit switch?

Measured temperature is below the temperature specified on the limit switch, which would indicate it is defective.

When calibrating a thermometer, how do you perform an ice water test?

Fill a glass with crushed ice and then add water almost to the top. Insert the thermometer tip/probe and hold for 30 seconds.

the typical gas line delivery pressure is ____________ and the typical appliance manifold pressure is ___________ .

11 " W.C., 10 " W.C.

Negative pressure is also called ________ .

Vacuum

Use a ____________ to calibrate other pressure measuring devices such as an electronic manometer, magnohelic gauge, or dial gauge.

Water manometer

Combustible gas detectors (CGD) are instruments typically calibrated for __ specific gas, such as _______.

1, propane

A Combustible Gas Indicator (CGI) can also signal an alarm when the level of gas concentration in the air reaches/exceeds preset points marking the flammability range. These presets points are called ____ or ____ for ____________ or ____________.

LEL, LFL, Lower Explosive Limit, Lower Flammability Limit

Flammability range for propane:

2.15% to 9.6% of air

_________ are two pieces of metal known to expand at different rates when heated. ________ sense temperature change and either open or close a switch.

Bimetals

________ can be formed into a number of shapes; straight, U-shaped, disc shaped, and coiled.

Bimetals

A ________ used as a safety switch generally is normally closed (NC) and opens on a temperature rise.

bimetal

A bimetal sensor rated L140-40F is operating correctly if the switch opens at 120 degrees, T/F?

False

_______________ sensors are used on storage water heaters to sense the temperature of water inside a water heater activate a switch that allows gas to flow to the burner to heat water.

Rod and tube

Rod and tube sensor assembly includes an ________________ which cannot be replaced separately.

Energy Cutoff Sensor (ECO)

if a fusible link used as a flame rollout sensor opens w/ no flame rollout, then measure the actual ____________ next to the fusible link and compare measurement to the ____________ on the switch and the manufacturers specifications.

Temperature

If a non-resettable flame rollout switch opens, it must be _________ .

replaced

when an ECO is used with a water heater gas control valve, verify loss of __________ through the ECO.

millivolts

___________ switches sense the flow of air. The __________ is a type of ________ switch that can be used on propane appliances.

Air flow, sail switch, air flow

If a fuse is blown, there is a short somewhere in the ________ .

circuit

for Low Water Cutoff devices (LWCO), follow the __________________ for maintenance of these devices.

manufacturers instructions

Centrifugal switches are found on _____________ .

RPM sensors

Watts Law:

W = V x A

The key when replacing a transformer is to be certain that you match the ____________________ and the ____ rating.

voltage (primary & secondary), VA

The part of the transformer that usually fails is the ________. the ________ is made from a very thin metal thread that can get too hot and burn if too much electricity is applied

winding

If the output voltage of a transformer is within 5% of its rating, the transformer is considered _______ .

good

if the output voltage of a transformer is not within 5%, then check the ___________ .

input voltage

When checking input voltage of a transformer, the voltage reading should be between ______ and _______ .

115V - 126V (+/- 5%)

For a transformer, if you suspect that there is a short in the 24V circuit, trace the circuit and try to find the short. If no problem is found, consider installing an __________ rated for the circuit amperage.

in-line fuse

The three places a relay coil can fail:

- break or short in the coil

- blockage of mechanical movement of switches

- incomplete connections at contact points

When testing relay contacts, either a ________ or _________ test can check if the switch is working properly.

voltage, resistance

Most _______ cannot be repaired by the technician, therefore, a faulty _______ should always be replaced. Be sure to match coil rating.

relays, relay

Motors have two main components; a ______ and a ______. A ______ is the rotating part of the motor, and the ______ is the stationary part of the motor.

rotor, stator, rotor, stator

A ____________ is used only for a short time to give little extra power to start a motor. Any _________ over 70 microfarads is a ____________ .

start capacitor, capacitor, start capacitor

A ____________ operates for the entire cycle of the motor operation.

run capacitor

the ________________ is adjustable and should be set to the same value as the total current draw of the components in the heating circuit in order to keep the appliance cycling properly.

heat anticipator

_______________ are safety devices.

High limit controls

Most high limit controls are a ____________________ heat sensitive electrical switches that open on a temperature rise.

normally closed (NC) single pole single throw (SPST)

A common cause of no heat service calls is that a ________________ has opened.

limit switch

When the pilot flame does not light, remember to verify if there is gas in the _______________ and that the system pressure _________ are working properly.

propane container, regulators

When the pilot burner starts to get dirty, the pilot flame turns ________.

yellow

When the pilot flame is noisy, the cause of a loud and blowing pilot flame may be that the wrong pilot ________ was installed, or the gas pressure to the ____________ could be too high

orifice, pilot assembly

two tests for measuring the DC voltage generated by the thermocouple when the pilot is lit:

An open circuit test, a closed circuit test

Complete the ____________ first because it will tell you if you have a good thermocouple.

open circuit test

The thermocouple is working properly if the voltage is reading is at least within the range specified by the manufacturer, typically ______________.

20-30 Millivolts

Oven pilot systems have two pilot flames: a smaller _____________ and a larger ____________. The ___________ stays lit all the time, even when the oven control knob is off. When the oven thermostat is turned on, more gas is supplied to the pilot burner, which then enlarges the flame, making it a ____________ .

constant pilot, heater pilot, constant pilot, heater pilot

All electrodes will spark at a rate of approximately ___________ per second.

2 1/2 pulses (sparks)

For an oven burner, the electrodes spark approximately ____________ . The oven burner should ignite within ____________.

1 1/2 pulses (sparks), 60 seconds

Some ovens have an electronic ignition system that does not involve a pilot flame. Instead, they use a hot surface igniter often called a ___________ .

glow bar

The three components of hot surface ignition systems are wired in _______ .

series

When the surface igniter reaches a very high temperature (1800 to 2500 degrees), the current is high enough to open the ____________ .

gas valve

As the gas flows from the valve to the burner, some of the gas flows across the ______________ and ignites.

hot surface igniter

Ignition should occur within ______________ from the call for heat.

30 to 90 seconds

When the igniter glows w/ no ignition, measure the _______ in the ignition circuit.

current

the __________ increases as the igniter heats up.

amperage

For millivolt operators, the power source for the control circuit is a thermocouple or pilot generator, that produces ____________ of power.

540-750 millivolts

A thermopile is energized when the _________ surrounds the tip of the thermopile. The thermopile provides the power to operate the ______________ through the thermostat circuit.

pilot flame, gas control valve

Millivolt gas control valves are commonly used in gas fireplaces, hearth stoves, and ______________.

pool heaters

A 24-volt operator is commonly used for appliances such as ________ and _________ that have standing pilot or electronic ignition systems.

furnaces, boilers

For appliances that have an external source of electricity, the _____________ often wired into the low voltage circuit on the _____________ side of the transformer.

gas control valve, secondary

For line voltage operators, the main valve is operated by the _______________ .

line voltage circuit

Almost 120 volts are used to power the igniter. Generally only ___________________ are required to operate the gas valve, depending on the type of valve and igniter.

3 volts (and 3.2 to 3.5 amps)

Gas control valves with hydraulic operators have a remote temperature sensing bulb that is connected to the gas control valve by a _________________.

capillary tube

Most gas valves in basic propane appliances are _________________.

standard opening

__________________ gas valves are used with some older mobile home furnaces.

slow opening

A _______________ gas control valve is similar to a standard opening gas control valve for other operators.

snap-action

The second main valve is for additional security, cuts off the _______________ when there is no call for heat.

flow of gas

The manual _____________ knob on the top of the standing pilot gas control typically has 3 settings: OFF, PILOT, & ON.

gas control

For dual/redundant valves, the main valve is operated by a ____________.

solenoid

The gas pressure at the gas control valve outlet should match the manifold pressure listed on the _________________________.

appliance nameplate

Most gas control valves have at least ___ safety shutoff device to shutdown the appliance when there's a potentially unsafe condition.

one

The three most common pilot safety shutoff devices are:

- Thermocouple

- Thermopile

- Oxygen Depletion Sensor (ODS)

Once the safety valve has closed, the pilot must be manually ________. The reset button must be held down long enough to warm up thermocouple.

relit

________________ were developed for unvented room heaters.

Oxygen Depletion Sensor (ODS)

The ________________ generally includes tips for troubleshooting gas controls.

manufacturers documentation

When the pilot does not light, conduct a sniff test and wait ___ minutes between attempts to relight pilot.

5

Remember to turn the gas control knob to ________ and to hold the rest button/gas control knob all the way down for a minute after lighting pilot flame.

PILOT

Verify there is gas present at the pilot ______________ of the gas valve when depressing the gas control knob/rest button when in PILOT.

outlet tube

When the pilot goes out when the knob is released, check the thermopile or ___________________ to hold the safety valve open.

thermocouple voltage

A gas control valve should be replaced if it is difficult to turn by hand, T/F?

True

Pressure regulated propane vapor is delivered from the gas control to the burners by supply lines or by a _____________.

manifold

Burner ___________ are mounted on the manifold and aligned with the opening to each burner.

orifices

For single burners, the __________ is installed at the end of supply line.

orifice

As propane vapor passes through orifice to the burner, it mixes with _________________ .

primary air

Pending on design of appliance, the burner may be inserted into or placed adjacent to a _____________________, which transfers the heat from burners to air, water, and cooking oil.

heat exchanger

Some propane appliance have a single burner, while others have multiple burners mounted to a rack. The pilot flame ignites the gas in one of the burners and a __________________ carries the to the other burners.

crossover bar

There is an orifice at the end of the pilot gas tubing that connects to the __________________ with a compression fitting.

pilot burner

For primary air adjustment, first step is to verify the _______________________ is correct at outlet valve.

manifold gas pressure

Plug type orifices are used in ___________ systems.

heating

Cap type orifices are used in _____________ systems.

cooking

Fixed orifices are often referred to as ________.

spuds

The propane flow rate through an orifice and into the burner depends on the orifice size and gas pressure at manifold. The flow rate is measured in ___________________ .

British Thermal Units (BTU)

Use the ___________ orifice that does not exceed the BTU/rating of the appliance.

largest

if you need to increase orifice size, replace orifice with correct one or you can _______ to correct size.

drill

For flame rollout, an air adjustment will fix the problem, T/F?

False