Electronic Control Unit
Electronic Control Unit
How does a 2 wire 24 volt ac electronic thermostat work to control a gas fired furnace ?
Have moved into a house where previous owner replaced simple mechanical type thermostat (with mercury bulb) with an electronic unit. Mechanical type obviously just closes a contact to complete the gas valve circuit and so get 24V across gas valve coil.
Obviously 2 wire electronic unit cannot do this because the unit needs to draw power for the electronics.
The new thermostat is giving unreliable operation, am thinking of replacing it with the old unit which I found and appears to be functional (checked with multimeter).
Extra information :
Heater only, have used W and R terminals at furnace, also used W and R at thermostat. The thermostat also has Y and G terminals but no wires connected to these.
you are correct, the electronic tstat needs to be powered, some cheaper thermostats will operate on 2 AA batteries(junk in my opinion) or the other will actually be powered from the 24 volts on the unit transformer, verify that its wired correctly, is this just a furnace or is there also a cooling unit with this system?
heat only:
you should have 3 wires, one wire connected between Rh on unit and Rh on stat, one wire between C on unit and C on stat, and one wire between W on unit and W on stat.
the wires to Rh and C will power the stat, W is the open contact on the stat that will close when a call for heat has occured.
Quartet Technology ECU - Environmental Control Unit for MS, ALS, Cerebral Palsy, quadriplegia ...
CHECK OUT THESE GREAT PRODUCTS BELOW:
 |
 FORD 96 CONTOUR MISC CONTROL UNIT RELAY 1996 ELECTRONIC  US $30.00
|
 FORD 96 CONTOUR MYSTIQUE ENGINE ELECTRONIC CONTROL UNIT US $79.99
|
 ACDelco 16236757 Remanufactured Electronic Control Unit US $40.00
|
 ACDelco Remanufactured Electronic Control Unit 8896113 US $19.99
|
 ACDelco 88999152 Remanufactured Electronic Control Unit US $40.00
|
 ACDelco 88999170 Remanufactured Electronic Control Unit US $80.00
|
 Standard Motor Products EM7748 Remanufactured Electronic Control Unit US $132.87
|
 ACDelco 16190397 Electronic Control Unit Chip NOS US $19.99
|
 ACDelco 16088388 Electronic Control Unit Chip US $34.99
|
 Pioneer DEH-2200UB CD Receiver with iPod Direct Control and USB Input List Price: Sale Price: $79.99 You save: $55.01 (41%)  Eligible for free shipping!Availability: Usually ships in 24 hours  |
 Metra Axxess ASWC Universal Steering Wheel Control Interface (Black) List Price: Sale Price: $42.53 You save: $33.16 (44%) Eligible for free shipping!Availability: Usually ships in 24 hours |
 Sony CDXGT550UI MP3/WMA/AAC Player CD Receiver with iPod Direct Control via USB List Price: Sale Price: $107.99 You save: $21.96 (17%) Eligible for free shipping!Availability: Usually ships in 24 hours |
 Pioneer DEH-4200UB CD Receiver with OEL Display and USB iPod Control List Price: Sale Price: $99.99 You save: $100.01 (50%) Eligible for free shipping!Availability: Usually ships in 24 hours |
 Pioneer DEH-3200UB CD Receiver with iPod Direct Control and USB Input List Price: Sale Price: Too low to display Eligible for free shipping!Availability: Usually ships in 1-2 business days |
 Sony CDXGT540UI MP3/WMA/AAC Player CD Receiver (Black) List Price: Sale Price: $91.76 You save: $48.19 (34%) Eligible for free shipping!Availability: Usually ships in 24 hours |
 Kenwood KDC-MP145 In-Dash CD/MP3/WMA Receiver with Aux Input List Price: Sale Price: $67.90 You save: $32.09 (32%) Eligible for free shipping!Availability: Usually ships in 1-2 business days |
 Dual XDM6350 AM/FM/CD Receiver with USB iPod Control and AUX Input List Price: Sale Price: $69.99 You save: $82.97 (54%) Eligible for free shipping!Availability: Usually ships in 24 hours |
 Clarion CZ300 In-Dash CD / MP3 / WMA / AAC Receiver with USB List Price: Sale Price: $95.95 You save: $84.04 (47%) Eligible for free shipping!Availability: Usually ships in 24 hours |
 Holley 534-55 Replacement Electronic Control Unit for 1 and 2-Barrel Digital Pro-Jection Systems Sale Price: $287.91 Eligible for free shipping!Availability: Usually ships in 24 hours |
|
|
Garmin Electronic Control Unit (ECU) for GHP10 Autopilot $529.99 GARMIN ECU FOR GHP10 AUTOPILOT ELECTRONIC CONTROL UNITECU, Electronic Control Unit For GHP10The GHP 10 marine autopilot adds a whole new level of versatility to the Garmin marine line. This breakthrough unit gives power boat users an easy to use autopilot system to rely upon for auto-guided navigati |
|
|
Garmin Ecu Electronic Control Unit F/Ghp10 Autopilot 0101105300 $589.44 Garmin Ecu Electronic Control Unit F/Ghp10 Autopilot 0101105300 |
|
|
Garmin 010-11053-00 Electronic Control Unit for GHP10 Autopilot $523.95 "Garmin Electronic Control Unit (010-11053-00) Brand New Includes One Year Warranty, The Garmin 010-11053-00 is One of five main components of the GHP 10 autopilot system. The ECU connects and powers the course computer unit (CCU) and the hydraulic pump, controlling the pump based on information received from the CCU. 010-11053-00 Features: Electronic Control Unit, Connects & Powers CCU & Hydraulic Pump, for Garmin GPS Models: GHP: 10" |
|
|
Megatech Megapro Electronic Speed Control Unit $46.87 This is the replacement electronic speed control (ESC) unit for the remote control Megatech MegaPro Truck and Buggy. If an unfortunate accident has left you needing replacement RC car and vehicle parts then look no further than RC Hobby Explosion. Made with the Best Quality Material with your child in mind. Top Quality Children s Item. Megapro Electronic Speed Control Unit. |
|
|
ApexI EL II Electronic Meter Control Unit Gauge $84.99 ApexI EL II Electronic Meter Control Unit GaugeThe EL II System Meters are the newest addition to the EL Meters lineup. The 60mm System Meters utilize a main control unit which constantly monitors the movement of all of the gauges. The control unit c |
|
|
Engine Control Unit $78.07 An engine control unit (ECU), also known as powertrain control module (PCM), is a type of electronic control unit that determines the amount of fuel, ignition timing and other parameters an internal combustion engine needs to keep running. It does this by reading values from multidimensional maps which contain values calculated by sensor devices monitoring the engine. Before ECUs, fuel injection, ignition timing, and idle speed were directly controlled by mechanical and pneumatic sensors and actuators. Author: Miller, Frederic P./ Vandome, Agnes F./ McBrewster, John Binding Type: Paperback Number of Pages: 84 Publication Date: 2009/12/29 Language: English Dimensions: 5.98 x 9.01 x 0.20 inches |
|
|
Dual Channel Electronic Massage Unit $15 Dual Channel Electronic Massage Unit |
|
|
Electronic Advance Ignition Control $179.99 Electronic Advance Ignition Control; |
DRS Defense Solutions Wins $37 Million Contract for Jordanian Electronic Warfare Battalion System
BETHESDA, MD--(Marketwire - 12/29/10) - DRS Defense Solutions, LLC, a wholly-owned subsidiary of DRS Technologies, Inc., announced today that its Intelligence, Communications and Avionics Solutions (ICAS) business unit in Merrimack, NH, was awarded a $37.1 million contract for the production of an Electronic Warfare Battalion (EWB) System for the Jordanian Armed Forces. Under terms of this ...
