Weil-McLain 4 Series Manual page 127

®
Series 4
Maintenance
Accessing & c leaning exchanger: Ultra-155,
-230, -299/310 and -399 Only
1. Close the external manual gas valve.
2.
3. Disconnect the fl exible gas line at its fl are fi tting.
4. Remove the air silencer by lifting the plastic clamp off of the gas
line and then gently sliding the air silencer down and off the valve.
5. Remove hex head nuts (10mm box end wrench) from heat exchang-
er cover plate and remove burner cover plate from heat exchanger.
6. Pull the entire blower/venturi/gas valve/cover plate assembly out
of the boiler. (See Replacement parts section for component iden-
tifi cation and locations.)
7. Remov e three (3) M4 hex head screws (7mm box end wrench) and
burner clips securing burner to cover plate. Remove cover plate.
8. Use a vacuum cleaner to remove any accumulation on the heating
surfaces. Do not use any solvent.
9. If the vacuum cleaner is unable to clean completely, wash the
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 127, page 126 .
10. Inspect the heat exchanger cover plate insulation and gasket. Re-
place if damaged. Read the ceramic fi ber WARNING on page 109
before handling or disposing of ceramic fi ber materials.
11. Replace the burner, hex head screws and burner clips removed in
step 7. See Figure 120, page 112 .
12. Place cover plate gasket in groove of heat exchanger cover plate.
Replace cover plate.
13. Reinstall hex head nuts on the cover plate mounting studs and
tighten in a staggering pattern until cover plate is uniformly
tightened.
You must gradually tighten the cover plate nuts. For
Ultra-155 through -399, follow the tightening sequence
shown in Figure 128 , making two or three passes with
a torque wrench. The fi nal torque MUST NOT exceed
50 inch-pounds, +/- 10 inch-pounds.
14. Reinstall air silencer by sliding on gas valve venturi and securing
clamp to gas line.
15.
16. Reconnect the fl exible gas line and gas valve electrical plug.
17. Perform a soap suds leak test on all interior gas piping after start-
ing the boiler.
Cleaning the hea t exchanger — water side (ALL
models)
1. Follow the procedure given in "Clean the cast aluminum heat ex-
changer when required — water side," page 125 to clean the water
side of the exchanger.
2. Follow the complete procedure for boiler and system start-up,
beginning on page 35 .
Part number 550-100-400/0119
gas-fired water boiler — Boiler Manual
(continued)
Figure 128
WATER SPRAY HEAT EXCHANGER
PINS AFTER USING CLEANING TOOL
1. After using the cleaning tool as shown in Fig-
ure 127, page 126 , spray water downward from
above the pins to fl ush remaining sediment.
2. Remove sediment from the bottom of the heat
exchanger.
3. Then disconnect the condensate line at the bottom
of the heat exchanger.
a. Loosen the hose clamps at both ends of the
condensate line.
b. Remove the line and place a pan under the trap
connection.
c. Spray water into the bottom of the heat ex-
changer to fl ush remaining sediment to the
condensate outlet.
d. Spray water through the condensate line to
clean it thoroughly.
e. Remove pan and replace the condensate line.
f. Follow instructions on page 126 or page 127
to check components and replace burner and
cover.
127