Specifications

Part number 550-100-090/0809
g a s -f i r e d w a t e r b o i l e r — Boiler Manual
110
Maintenance (continued)
Nut tightening sequence — 80 & 105 Figure 113
Gradually tighten the nuts, repeating
the sequence shown below until the
torque reaches 50 inch-pounds (+/- 10
inch-pounds)
Cleaning the exchanger pin-sideFigure 114
Accessing & cleaning exchanger:
Ultra-80 and Ultra-105 Only
Close the external manual gas valve. 1.
Disconnect the flexible gas line at its flare fitting.2.
Remove the air silencer by separating it from the air adapter on 3.
the blower inlet.
Disconnectwiring:•gasvalveplug•blowerpowersupplyplug4.
•blowercontrolconnector•ignitioncable•groundwire.
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 heat-8.
ing 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 114.
See water spraying notice on next page.
Inspect the heat exchanger cover plate insulation. Replace if insu-9.
lation is damaged. Read the ceramic fiber WARNING on page 93
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 113, making two or three passes with a torque
wrench. The final torque MUST NOT exceed 50 inch-
pounds, +/- 10 inch-pounds.
Reconnectwiring:•gasvalveplug•blowerpowersupplyplug11.
•blowercontrolconnector•ignitioncable•groundwire.
If the valve adapter block is removed, carefully inspect the
O-ring that should still be in the gas valve inlet adapter
block. The O-ring must be in good condition 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 flexible 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 ex-
changer when required — water side,” page 109 to clean the water
side of the exchanger.
Follow the complete procedure for boiler and system start-up, 2.
beginning on page 31.