Hayward Universal H-Series Low NOx Service/Installation: H150FDN H200FDN H25 - Page 49

49 Transformer: The transformer converts the field supply voltage (either 240 VAC or 120 VAC) to a 120 VAC output for blower and igniter power, and a 24 VAC output for powering the ignition control board, control circuits, and gas valve. See Figure 42 for its location. To replace the transformer: 1. Turn pump, gas supply, and heater power "OFF". 2. Remove the front access panel. It is secured with (4) screws. 3. Remove the control box cover. It is secured with (2) screws. 4. Disconnect all wires from the transformer leads. 5. Remove the (2) screws that secure the transformer to the control box. 6. Replace the transformer. Reassembly is the reversal of steps 1 - 5. blower: The blower provides the air that mixes with the gas at the main burners for the combustion process. The blower operates during the prepurge time (approximately 30 seconds) at the beginning of each ignition cycle, during the entire time the gas valve is open and the burners are firing, and for 30 seconds after the valve gas closes. See Figure 49 and Figure 42 for the location of the blower. To replace the blower: Figure 49: 1. Turn pump, gas supply, and heater power "OFF". Blower: 2. Remove the front access panel (4 screws). 3. Remove the control box cover (2 screws). Blower 4. Disconnect the blower wire harness from the ignition air inlet control board. plate 5. Pull the tubing from the hose barb on the blower housing. 6. Remove the air inlet screen from the blower (4 screws). 7. Remove the blower from the air box cover (3 screws). 8. Slip the blower from beneath the securing flange. Blower outlet 9. Reverse steps 1 - 8 to install the new blower. gasket Be sure the blower outlet gasket is in place before proceeding. BYPASS SERVICE CARTRIDGE: Attach tubing here only The following procedure details how to remove and replace the internal pressure bypass valve in the header. This procedure applies only to plastic (non-ASME) headers. On bronze (ASME) headers, the bypass service cartridge is not field-replacable. Please contact Hayward technical support for more information. 1. Turn pump, main gas valve, and heater power off. 2. Drain heat exchanger according to instructions on page 39. 3. Remove 6 screws and remove the upper plastic heater side panel, to allow access to the header. 4. Remove the cartridge retaining nut from end of header (see Figure 36). 5. Slide out the bypass cartridge from the end of the header (see Figure 36). 6. Check the function of the bypass valve to ensure the valve flaps rotate smoothly on the shaft, and the spring fully closes the valve. 7. Apply silicone o-ring grease (Hayward Jack's 327 Multilube p/n SP032712, or equivalent) on o-ring seals on the bypass cartridge before inserting into the header. 8. Insert bypass cartridge into header with the arrow on the end of the cartridge pointing up. 9. Re-install cartridge retaining nut. Nut should be tightened hand-tight only. DO NOT OVER-TIGHTEN. 10. Re-install the upper plastic heater side panel. USE ONLY HAYWARD GENUINE REPLACEMENT PARTS Pomona, CA Clemmons, NC Nashville, TN Tel: 908-351-5400 www.haywardpool.com