Power Supply for single cell F50A and F50E 240v 12½ x 20. Ionizer current is preset to 1.05mA. This power supply is for power boxes without the W8600 terminal strip and without the air flow sensor. Honeywell 2 year warranty.
The circuit board has an approximate size of 4½ x 6½ x 1¾ inches. This kit includes the power supply with the wiring harness and terminal strip. Also included is the metal base.
Replaces 203362K 220429FXB 220429GXB 220429HXB W919A1366 W919A1556. For 120v use the 208425G or 208422A.
The 208425E power supply does not provide a connection for the W8600 remote indicator. The 208425E is for a power box without the terminal strip as in photo below on left. If your power box has a terminal strip for the W8600, then this power supply does not have the connection for that terminal strip.
If your powerbox has an unused terminal strip because you are not using the W8600, then you can use this power supply and internally not connect the unused terminal strip.
The 208427 power supply series provides a connection for the W8600. The 208427 power supply was made for a power box that has the terminal strip.
The 208425E does not require an air flow sensor. This power supply runs as soon as 240v is applied. Used in an F50A-E that is wired to the furnace blower or through a sail switch.
This power supply has been configured for use in a power box without the air flow sensor. The animated photo below shows a power box with and without the air flow sensor.
Honeywell has disabled the air flow sensor feature by cutting the jumper J8. Restoring the jumper will allow the use of an air flow sensor. If your F50A-F50E power box has the air flow sensor and it is needed, then you need to replace the complete power box with the 208422B.
Here is a PDF with high resolution photos of the F50A power box. The photos show the box stripped and then with a new 208425A installed. Also shown is a photo and schematic of the switch with the neon lamp.
Also see the PDF showing the uncommon edge connector and the piggy back connector.
First visually inspect your board. Most problems are visible such as a melted transformer winding or a burnt component such as the surge suppressors RV1 RV2. Check the thin white ceramic resistor R3, the corner wire can break away. This can cause the collector plates to get power but not the ionizer wires.
Continuous cell sparking (for months) can burn out components or wiring. Resonant sparking causes elevated voltage swings that can break down the insulation on the high voltage wires. Check for scorching.
Often the fuse blows when the switching FET Q1 shorts, we believe from line spikes. Check the fuse continuity. A blown fuse typically reads 4.4M ohm because of circuitry in parallel.
The fuse is soldered in and not replaceable. If there is an internal short the fuse blows so to prevent any components from flaring up. Replacing a blown fuse will not fix the problem.
Honeywell does not release the circuit board schematics. Service tech's want to replace the complete board and be confident. Honeywell does not sell the discrete components. We do not do component level repair of the boards.
Replacing the complete board with a new one with a 2 year Honeywell warranty would be the most reliable repair.
Here is our procedure to test the 208425E power supply. Warning high voltage shock can cause death.
The 208425E has the air flow sensor disabled, the jumper J8 has been cut. This power supply does not require the air flow sensor to operate. The photo below shows the power supply just needs 240v to power a cell.
Connect 240 vac to terminals P1 and P2. Check the following outputs with respect to chassis ground.
