Part number 550-100-026/0404
GAS-FIRED WATER BOILER SERIES 2 — Boiler Manual
34
Cleaning boiler heat exchanger
(continued from previous page)
Access exchanger: Ultra-155, -230, -310 Only
1. Remove gas valve electrical plug from gas valve. Also
remove two electrical molex plugs from blower
assembly.
2. Disconnect gas line union with pipe wrench or
Channel Lock Pliers.
3. Remove air silencer by lifting plastic clamp off gas
line and then gently sliding air silencer down and off
valve.
4. Remove two 5/32” Allen head screws securing blower
assembly to heat exchanger front cover.
5. Remove blower and gas valve assembly.
6. Remove hex head nuts (10mm box end wrench) from
burner cover plate and remove burner cover plate
from heat exchanger.
7. Remove three 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
necessary, use a piece of 20-gauge or lighter sheet
metal ¾" wide by about 18 inches long to loosen
deposits.
10. Inspect the heat exchanger cover plate insulation and
gasket. Replace if damaged. Read the ceramic fiber
WARNING on page 29 before handling or disposing
of ceramic fiber materials.
11. Place cover plate gasket in groove of heat exchanger
cover plate. Replace cover plate.
12. Re-install hex head nuts (10mm box end wrench) on
cover plate mounting studs and tighten in a staggering
pattern until cover plate is uniformly tightened.
13. Re-install blower insuring new gasket, provided in
this kit, is in proper alignment between blower and
heat exchanger front cover.
14. Re-install air silencer by sliding on gas valve venturi
and securing clamp to gas line.
15. Connect the two blower electrical molex plugs.
16. Re-connect gas valve union and gas valve electrical
plug.
Exchanger cleaning continued (ALL models)
1. Close isolation valves on piping to isolate boiler from
system. Attach a hose to boiler drain valve and flush
boiler thoroughly with clean water by using purging
valves to allow water to flow through water make-
up line to boiler.
2. When boiler has been flushed, restore boiler to
operation.
3. Perform startup and checkout procedures of pages 23
and 26.
4. Turn on gas supply and check for gas leaks.
Failure to properly check for gas leaks can
cause severe personal injury, death, or
substantial property damage.
5. Turn on boiler electrical supply and test boiler for
proper operation as stated in the Ultra Boiler Manual.
6. Replace boiler jacket front door when servicing is
completed. See Warning at top of page 33.
Maintenance and annual startup
(continued)
8b