LAARS Pennant PNCV (Sizes 500-2000) - Install and Operating Manual - Manual (Page 50)

LAARS Heating Systems Page 50
6. Allow the heat exchanger to drain. Remove the
front cover(s) by removing the rubber access
strip(s) and the retaining screws. Remove the
venting and remove the top, by removing the
screws that attach the top to the side panels.
Remove the side panels. Remove the front lower
panels sealing the combustion area. To remove
the gas train, disconnect the unions located
below the intermediate pan and the field installed
union located outside the cabinet, and pull up,
bringing the union end connectors through the
grommets in the intermediate pan. To remove the
intermediate pan, remove the slide out control
assembly and blower(s) to reveal the screws.
Remove the screws holding the intermediate pan,
and lift up to remove it. The heat exchanger has
integral metal sections attached, which connect
to the frame of the boiler. Locate and remove
the screws along the front, rear and bottom of
the integral metal sections, and remove the heat
exchanger and metal sections by lifting up.On the
larger appliances, a center heat exchanger support
must be unbolted before it can be removed.
7. Remove the heat exchanger from the unit.
NOTE: The heat exchangers are heavy and may
require two people to remove to avoid personal injury.
8. Clean the heat exchanger: A light accumulation
of soot or corrosion on the outside of the heat
exchanger can be easily removed. Use a wire
brush to remove loose soot and scale from the
heat exchanger. Do not use water or compressed
air for cleaning.
9. While the heat exchanger is out of the unit,
inspect the firewall refractory insulation. Replace
if necessary.
10. Inspect the inside of the copper tubes for scale
buildup. Scale can build up on the inner surface
of the heat exchanger tubes, which can restrict
water flow. If the tubes show signs of scaling,
clean the internal surface. Laars offers a tube
cleaning kit part number R0010000.
11. Reassemble in the reverse order, and check
appliance operation after start-up.
NOTE: The Warranty does not cover damage
caused by lack of required maintenance, lack of
water flow, or improper operating practices.