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BYPASS SERVICE CARTRIDGE:
The following procedure details how to remove and replace the internal pressure bypass valve in the
header.
1. Turn pump, main gas va
lve, and heater power off.
2.
Drain heat exchanger according to instructions in Section III of this manual.
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 24).
5.
Slide out the bypass cartridge from the end of the header (see Figure 24).
6.
Check the function of the bypass valve to ensure the valve fl aps rotate smoothly on the shaft, and the
spring fully closes the valve.
7. Apply silicone o-ring grease (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.
