Installation Guide
Part number 550-100-066/0608
g a s -f i r e d w at e r b o i l e r — Boiler Manual
90
Maintenance (continued)
Accessing & cleaning exchanger:
Ultra-80 and Ultra-105 Only
Close the external manual gas valve. 1.
Disconnect the exible gas line at its are fitting.2.
Remove the air silencer by separating it from the air adapter on 3.
the blower inlet.
Disconnectwiring:•gasvalveplug•blowerpowersupplyplug4.
•blowercontrolconnector•ignitioncable•groundwire.
Release the heat exchanger cover plate by removing the nuts secur-5.
ing it to the exchanger.
Pull the entire blower/venturi/gas valve/cover plate assembly out 6.
of the boiler. (See Replacement parts section for component iden-
tification and locations.)
Use a vacuum cleaner to remove any accumulation on the heating 7.
surfaces. Do not use any solvent.
If the vacuum cleaner is unable to clean completely, wash the 8.
heating surfaces with clean, warm water. If further cleaning is
necessary, use the Heat Exchanger Cleaning Tool (see Replacement
parts at the end of this manual) or a piece of 20-gauge or lighter
sheet metal ¾” wide by about 18 inches long to loosen deposits.
See Figure 98.
Inspect the heat exchanger cover plate insulation. Replace if insu-9.
lation is damaged. Read the ceramic fiber WARNING on page 79
before handling or disposing of ceramic fiber materials.
Reinstall the blower/venturi/gas valve/cover plate assembly and 10.
secure the cover plate with nuts.
You must gradually tighten the cover plate nuts. For Ul-
tra-80 and -105, follow the tightening sequence shown
in Figure 97, making two or three passes with a torque
wrench. The final torque MUST NOT exceed 50 inch-
pounds, +/- 10 inch-pounds.
Reconnectwiring:•gasvalveplug•blowerpowersupplyplug11.
•blowercontrolconnector•ignitioncable•groundwire.
Inspect the O-ring that should still be in the gas valve
inlet adapter block. The O-ring must be in good condi-
tion and must be installed when gas valve is reconnected.
Failure to comply will cause a gas leak, resulting in severe
personal injury or death.
Reconnect the exible gas line.12.
Reinstall the air silencer by pressing onto the air inlet adapter.13.
Perform a soap suds leak test on all interior gas piping after start-14.
ing the boiler.
Cleaning the heat exchanger — water side (ALL
models)
Follow the procedure given in 1. “Clean the cast aluminum heat
exchanger,” page 72 to clean the water side of the exchanger.
Follow the complete procedure for boiler and system start-up, 2.
beginning on page 70.