UDS / UDH Series Ultra Low NOx Direct Vent Water Heaters SERVICE MANUAL Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) Models Covered by This Manual: ECO-Defender Safety System ® Models UDS140S*FRN UDS150S*FRN UDH1504T*FRN UDH165T*FRN UDH175S*FRN UDH50T45FR*N UDH65T45FR*N UDH75T50FR*N (*) Denotes Warranty Years Manual 238-49640-00A Save this manual for future reference
The Bradford White Ultra Low NOx Direct Vent Water Heaters Table of Contents Page Service Procedure Introduction 3 --- Trouble shooting Chart 4 --- Inner Door Gasket Removal, Inspection, Replacement and Installation 6 I Thermopile Testing and Replacement 9 II Pilot Assembly Inspection Cleaning and Replacement 10 III Igniter, Electrode Testing and Replacement 11 IV Honeywell Gas Control Testing, Disassembly, and Replacement 20 V Burner Operation Inspection, Adjustment, Cleaning and Re
INTRODUCTION The new Bradford White UDS and UDH water heaters are designed to provide reliable performance with enhanced standard features. Design features include reliable standing pilot ignition system, enhanced diagnostics, simplified servicing, certified FVIR technology and Ultra Low NOx emissions. The UDS and UDH water heaters use a combustion system where combustion air is drawn from the outside of the building. The gas control maintains water temperature and maintains gas flow.
Honeywell Gas Control Troubleshooting Chart Flammable Vapor Ignition Resistant Water Heaters Observe green LED indicator on Gas Control. Error flash codes are displayed with a three second pause before repeating. Check and repair the system as noted in the troubleshooting table below. LED Status Green LED Indicator Control Status None (LED not on or Pilot assembly is not lit flashing Probable Cause . Gas Control is not powered. Light pilot. If the pilot will not stay lit replace pilot assembly.
Honeywell Gas Control Troubleshooting Chart Flammable Vapor Ignition Resistant Water Heaters Observe green LED indicator on Gas Control. Error flash codes are displayed with a three second pause before repeating. Check and repair the system as noted in the troubleshooting table below. LED Status Green LED Indicator Control Status Five flashes and Thermostat/well sensor fault. three second pause Probable Cause Service Procedure 1. Damage to the temperature sensor. 1. See service 2.
The Bradford White SERVICE PROCEDURE I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Inner Door Removal Procedure Step 1. Rotate set point knob of the gas control to the “OFF” position. Step 2. Turn off the gas supply to the water heater Step 3. Remove the outer door. Step 4. Remove the four (4) ¼” hex drive screws holding the right side inner door in place Step 5. Remove the three (3) ¼” hex drive screws holding the left side burner door in place.
The Bradford White SERVICE PROCEDURE I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Inner Door Gasket Replacement Procedure. WARNING If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Step 10. After inspection of inner door as noted in step 9, completely remove gasket and adhesive residue from burner and left side inner doors as needed. Step 11.
The Bradford White SERVICE PROCEDURE I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Position fiberglass sock, pilot tube and armored thermopile cable against flange. Step 15. Firmly place right side inner door flange against the burner door flange and secure with two ¼” drive screws from step 5. DO NOT OVER TIGHTEN SCREWS. Step 16.
The Bradford White SERVICE PROCEDURE II Thermopile Testing and Replacement OPEN CIRCUIT THERMOPILE TESTING The following test should be performed while the pilot flame is on. Step 1. Turn knob to pilot position and depress. Step 2. Continue pressing knob and remove red (+) thermopile wire from the red wire leading from the gas control. Also remove white (-) thermopile wire from the gas control. Step 3.
The Bradford White SERVICE PROCEDURE III Pilot Assembly Inspection, Cleaning and Replacement For Honeywell Control, rotate knob counter-clockwise to the “OFF” position. PILOT/ELECTRODE ASSEMBLY INSPECTION, CLEANING AND REPLACEMENT Step 1. Turn off gas supply to water heater. Rotate knob of gas control/gas valve to “OFF” position. Step 2. Remove outer jacket door. Step 3. Remove burner and right side inner door per SERVICE PROCEDURE I, steps 1 through 8.
The Bradford White SERVICE PROCEDURE IV Igniter, Electrode Testing and Replacement IGNITER, ELECTRODE TESTING AND REPLACEMENT With the pilot not in operation (no pilot flame) you can check the igniter and electrode circuit by viewing pilot thru the sight glass located on the inner door and observing the spark action. Step 1. Remove outer jacket door. Step 2. Repeatedly depress the igniter while viewing the pilot thru the sight glass. If a spark is present, the circuit is OK.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement Honeywell Gas Control Testing, Disassembly, and Replacement The Gas Control is made up of (5) major components; the control cover, the piezo igniter, the valve body, the temperature sensor, and the back plate. The Gas Control is designed so that any of these components may be replaced without replacing the entire Gas Control.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement MANIFOLD PRESSURE TESTING (this procedure presumes a maximum line pressure of 14.0" w.c.) Step 1. Set the Gas Control to the “OFF” position. Step 2. Remove pressure tap plug and install 1/8" NPT pipe, coupling, & pressure tap. Step 3. Connect manometer to pressure tap. Step 4. Follow instructions located on the lighting instructions label and proceed to light the main burner and observe manometer reading.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement TEMPERATURE SENSOR TESTING CAUTION DO NOT use standard multimeter probes for this test. Doing so will damage connector. Use special pin type electronic probes or small diameter wire pins inserted into connector. If Control has gone into lockout due to excessive tank temperature (four flash, three second pause) reset control by rotating gas control knob to “OFF” position and wait a minimum of (5) minutes.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement WARNING Stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. DETERMINE WATER TEMPERATURE INSIDE TANK Note: It is important to understand once the resistance for the temperature sensor is determined from the previous page, water flow through the water heater should not occur.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement GAS CONTROL DISASSEMBLY/REASSEMBLY Step 1. Rotate knob of the Gas Control to the “OFF” position. Step 2. Turn off gas supply to water heater. Step 3. Disconnect gas supply line from Gas Control. Rotate knob counter-clockwise to the “OFF” posistion. Step 4. Disconnect igniter wire. Step 5. Disconnect main burner feedline, pilot tube and thermopile wires from gas control. Step 6. Remove Gas Control cover screw.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement GAS CONTROL DISASSEMBLY/REASSEMBLY Step 8. Disconnect temperature sensor from control board and remove wire from the temperature sensor wire routing clip. Temperature sensor wire routing clip Disconnect temperature sensor Step 9. Remove the piezo igniter from the control cover by releasing the lock tab on the control cover.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement GAS CONTROL DISASSEMBLY/REASSEMBLY Step 10. Remove the valve body by removing screw located at the lower left corner then unclipping the lower right side from the backplate first followed by the lower left side using a flat head screwdriver. CAUTION Use caution not to bend or damage valve body pins. Unclip lower right side first Unclip lower left side second Valve body screw Step 11.
The Bradford White SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement GAS CONTROL DISASSEMBLY/REASSEMBLY Step 12. Remove temperature sensor from insertion stick by pulling apart as illustrated below. Pull in this direction Temperature sensor Insertion stick Pull in this direction Step 13. To reassemble Gas Control, follow the previous steps in reverse order.
SERVICE PROCEDURE V Gas Control Testing, Disassembly & Replacement The Bradford White GAS CONTROL REPLACEMENT Step 1. Rotate knob of the gas control to the “OFF” position. Rotate knob counter-clockwise to the “OFF” position. Step 2. Turn off gas supply to water heater. Step 3. Disconnect gas supply line from gas control. Step 4. Turn off water supply and drain water heater completely. Step 5. Remove the wire clip from the feedline. Step 6.
The Bradford White SERVICE PROCEDURE VI Burner Operation Inspection, Adjustment Cleaning and Replacement MAIN BURNER: Inspection, Cleaning and Replacement At periodic intervals (not more then 6 months) a visual inspection should be made of the main burner for proper operation and to insure no debris is accumulating. Main burner should light smoothly from pilot and burn with a blue flame with a minimum of yellow tips.
The Bradford White Step 4. SERVICE PROCEDURE VI Burner Operation Inspection, Adjustment Cleaning and Replacement Disconnect (unscrew) feedline from the main burner door. Feedline Step 5. Remove main burner orifice from feed line (3/8" wrench). Inspect and clean if necessary Main Burner Orifice Step 6. Remove pilot assembly, refer to SERVICE PROCEDURE III for cleaning and inspection. Step 7. Reassemble burner. Step 8. Reinstall burner and inner door per SERVICE PROCEDURE I, steps 9 through 19.
The Bradford White SERVICE PROCEDURE VII Dip Tube and Anode Inspection and Replacement DIP TUBE INSPECTION AND REPLACEMENT WARNING Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Step 1. Rotate knob of gas control to “OFF” position. For Honeywell Control, rotate knob counter-clockwise to the “OFF” position. Step 2. Turn off cold water supply to heater.
The Bradford White SERVICE PROCEDURE VII Dip Tube and Anode Inspection and Replacement ANODE INSPECTION AND REPLACEMENT WARNING Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Step 1. Turn off water supply to water heater. Rotate knob of gas control to “OFF” position. For Honeywell Control, rotate knob counter-clockwise to the “OFF” position. Step 2. Turn off cold water supply to heater.
The Bradford White 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Generic Parts List Vent Package Air Intake Terminal Outer Wall Mounting Plate Backing Plate Telescopic Air Intake Tube Telescopic Vent Tube Intake Elbow Exhaust Elbow Plenum Flue Reducer Plenum Gasket Air Intake Tube Air Intake Terminal Guard (Optional) Flue Baffle Heat Trap (Inlet) Cold Water Inlet Tube Hot Water Outlet/Anode Heat Trap (Outlet) 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 T&P Relief Valve ¾” NPT Tank Plug (UDH