Install Instructions

Ultra-80 & Ultra-105
Cover Plate Replacement
Part number 550-100-055/0618
7
gas-fired water boilers — Heat Exchanger Block Replacement Instructions
Wait for the heat exchanger to cool down before
proceeding. Failure to do so can result in severe
personal injury.
1. Close external isolation valves on boiler water supply and
return.
2. Drain water from boiler using boiler drain valve.
3. Close manual gas valve to shut o gas supply.
4. Disconnect gas valve electrical plug and water temperature
sensors. Disconnect two (2) electrical plugs from blower
assembly.
5. Remove four (4) Phillips-head screws securing gas valve inlet
adapter to gas valve. is will disconnect the gas valve from
the gas line.
6. Remove the air silencer by separating it from the air adapter
on the blower inlet.
7. For the older style heat exchanger cover plate, use a 5/32
Allen wrench with a 5/16” wrench to re-
move the two (2) 5/32” Allen head screws securing
the blower and gas valve assemby to the cover plate.
For the new style heat exchanger cover plate, studs are used
instead of bolts and nuts. So remove the two (2) nuts with a
5/16” wrench from the studs. en remove the blower from
the cover plate.
Figure 7 M6 sensor (Lower sensor)
Figure 8 M6 sensor (Upper sensor)
See Figures 7 and 8, below showing location of the M6
sensors with adapters.
8. Remove blower and gas valve assembly.
Inspect the O-ring that should still be in gas valve
inlet adapter block. e 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.
9. Loosen boiler water supply compression nut and remove boiler
water supply pipe.
10. Loosen boiler water return compression nut and remove
boiler return water pipe.
11. Disconnect condensate trap hose by loosening band clamp
at bottom of heat exchanger.
12. Loosen, but do not remove, four (4) 7/16” block mounting
bolts on sides of heat exchanger block.
Do not remove 7/16” heat exchanger block mount-
ing bolts, as heat exchanger block is heavy and
weight can cause severe personal injury or sub-
stantial property damage.
13. Disconnect ground wire from igniter.
14. Disconnect ignition cable at electrode.
15. Li heat exchanger block assembly and slide forward out of
brackets to remove from boiler.
16. Remove four (4) bolts from sides of old heat exchanger block
and screw into new heat exchanger block, leaving enough bolt
exposed to slide into mounting bracket in boiler.
17. Carefully li new block and slide into boiler mounting brack-
ets and allow to drop into place.
18. Securely tighten the four (4) 7/16” heat exchanger block
mounting bolts.
1. Remove and discard the original igniter, igniter gasket and
mounting hardware from the heat exchanger cover plate
assembly.
2. Carefully remove any debris or residual gasket material from
the igniter gasket sealing surface on the front of the heat
exchanger cover plate.
3. Remove the heat exchanger cover plate by removing the nuts
securing it to the heat exchanger. Discard original mount-
ing hardware.
4. Replace the heat exchanger cover plate insulation using the
part provided in this kit. Read the ceramic ber WARNING
on page 4, before handling or disposing of ceramic ber
materials.