How many volts does it take to open the gas valve on a furnace?
24 volts
24 volts is given to the gas valve. The flame sensor starts detecting if there is a flame or not.
How do you check voltage on a gas valve?
Testing with a multimeter lets you know the valve works.
- Turn off the furnace at the wall control.
- Take out the bolts in the service panel on the side of the furnace using a nut driver.
- Pull the wires off the gas valve terminals.
- Turn the test control on the multimeter to “mV,” which stands for millivolt.
What causes furnace gas valve failure?
When They Fail The valve itself may have simply worn out or may be damaged due to basement seepage or submersion. Alternately, one of the electronic gas ignition components or a glitch in the safety circuit may be to blame. If your furnace has a standing pilot light, the thermocouple could be worn out.
Does heater need control valve?
That’s why it is surprising for some people to learn that the heater control valve is a necessary part of how the heater works because it allows coolant to pass from the engine itself through the car heater where it’s able to warm you up.
What should the valve voltage be on a 6.3V heater?
The heater voltage should be kept within +/-10% of its nominal value for optimum valve performance. For 6.3V heaters that means 5.7V to 6.9V, though it is even better to stay within +/-5% if you can (6V to 6.6V).
Why are ohms readings not used on gas valve coils?
Let me first say that using Ohms readings on gas valve coils is not the best way to troubleshoot them. One of the reasons is that some gas valves today use a diode built into the gas valve. This means that when 24 Volts AC is fed to the valve it is convertd to DC before it goes to the coil.
Where does the elevation voltage come from in a heater?
Another convenient source of elevation voltage is the cathode of a cathode-biased power valve. No current flows into the heater supply from here, so the power valve bias is not affected. The heater voltage should be kept within +/-10% of its nominal value for optimum valve performance.
What kind of DC supply do I need for a valve heater?
A simple voltage output DC supply with a long risetime (say 5 seconds or so) allows the heaters to come up to temperature smoothly. You could use an LM317 with a circuit like this (from the datasheet) which will ramp up from 1.25 V to the final voltage set by the R1, R2 divider.
What’s the best way to troubleshoot a gas heater?
1. Open electrical circuit. 2. Rotate heater’s manual gas valve knob to “OFF” position. -Digital Multimeter – Used for troubleshooting & testing electrical circuits. (Part 1A783 from Grainger) -Flame Rectification Meter – Used for testing rectification of flame with the digital multimeter. (Channel Products)
Is it safe to use a gas heater with an open flame?
CAUTION! Heater may be hot. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. Note presence of flammable gas and electrical shock hazard. WARNING! Extinguish open flame while servicing heaters. Test for gas leaks with soap and water solution only.
What are the safety switches on a gas heater?
The heater is equipped with 2 safety pressure switches. The burner switch in the blower compartment is a normally open switch and the exhaust switch in the gas valve compartment is a normally closed switch. Temporarily place jumpers across the terminals of each switch, one at a time. (Be sure to reinstall the cover.) Does the ignitor glow red? YES
What happens if you don’t follow the instructions on a hot water heater?
FAILURE TO COMPLY WITH THESE WARNINGS AND INSTRUCTIONS, AND THOSE ON THE HEATER, COULD RESULT IN PERSONAL INJURY, DEATH, FIRE, ASPHYXIATION AND/OR PROPERTY DAMAGE. RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE. CAUTION! Heater may be hot.