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Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit
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27
1. Turn the Steam Generation switch to the off position to drain the tank completely.
2. Tun off gas, electricity and water supply to the unit.
3. Using a vacuum, remove all dust from the control cabinet area, and blower assembly.
4. Disconnect the gas piping going to the gas valve.
5. Disconnect wiring harness to the blower assembly.
6. Unplug wires to blower and pressure switch.
7. Unplug flame detection rod and ifniter wires from module.
8. Remove the 4 bolts holding the blower assembly to the heat exchanger and remove the burner assembly.
9. Disconnect steam distribution piping from lid of unit, and remove lid from unit.
10. Disconnect Vent piping from exhaust nipple, or exhaust collection box.
11. Remove either exhaust nipple or exhaust collection boxby removing all the bolts holding it in place. Care
should be taken not to damage the gasket.
12. Remove the 12 bolts holding the front of the heat exchanger in place, and remove any additional bolts holding
the exhaust end of the heat exchanger in place.
13. Carefully lift the heat exchanger from the steam generation chamber.
14. The new heat exchanger will ship in two gaskets (shipped loose) for the inlet and exhaust connections of the
heat exchanger. Remove adhesive strips, and install gaskets on appropriate surfaces of the heat exchanger.
15. Carefully lower the heat exchanger into position in the steam chamber.
16. Install all required bolts into position in both the inlet and exhaust sides of the heat exchanger. In the case of
the GFH-150, the exhaust nipple must be installed prior to bolting the exhaust end of the heat exchanger
in place.
17. Snug all 12 bolts on the inlet side of the heat exchanger, and all 8 bolts on the exhaust end of the heat
exchanger.
18. Using Figure 27-1 torque all bolts to 50 in-lb in the order shown. Using the same torque pattern, continue to
torque all the bolts to the inal 70 in-lb torque rating.
19. VERIFY ALL BOLTS GET TORQUED PROPERLY ON BOTH THE INTAKE AND EXHAUST ENDS OF THE
HEAT EXCHANGER.
20. Replace the exhaust collection box. The gasket used between the tank and the exhaust collection box does
not have adhesive gasket, so care will have to be taken to make sure the gasket is in proper place.
21. Re-connect the exhaust vent piping to exhaust collection box, or exhaust nipple.
22. Re-install steam chamber lid, and re-connect steam distribution piping.
23. Re-install gasket, and burner assembly into heat
exchanger. Inspection of the gasket will be required if old gasket can be used, or should be replaced.
24. Re-connect gas supply line, turn gas on and check for leaks.
25. Re-connect all control wiring.
26. Apply power and turn Steam Generation switch to ON
position.
27. Verify normal operation outlined in Start-Up Section.
Removing / Replacing Heat Exchanger
8
10
12
1
3
5
7
9
11
2
4
6
2
7
5
3
1
8
6
4
Figure 27-1
