Maintenance Procedure To Clean Heat Exchanger - Heat Transfer MODCON VWH 300 LP Installation & Maintenance

PART 13: MAINTENANCE
d. Replace and tighten the (6) 10MM nuts to
the burner plate using staggered tighten-
ing sequence. (See detail)
e. Re-connect all wiring connections
f. Inspect gas valve to assure O-ring is in
place. Replace the (4) screws on the alu-
minum connector on the gas valve. Turn
the gas back on. (IMPORTANT: CHECK
FOR GAS LEAKS)
g. Turn the Mod Con Boiler power back on
and create a demand on the boiler. When
boiler is lit, observe condensate flow
from the boiler. Be sure the boiler is oper-
ating properly.
h. Re-connect the condensate piping to the
outside condensate connection.
65
GAS-FIRED HOT WATER SUPPLY BOILER
(CONTINUED)
C. MAINTENANCE PROCEDURE TO CLEAN
HEAT EXCHANGER:
1. Shut off power to the boiler.
2. Close ball valves on both inlet and outlet
of the heater.
3. Attach a hose to both the drain valves
located on the inlet and outlet. Feed both
hoses into a plastic bucket. Let heater
cool down to room temperature before
opening both drain valves. Please note
the amount of water content in each unit
varies – see chart:
Mod/Con 300 – 2.9 gallons water
Mod/Con 500 – 4.2 gallons water
Mod/Con 850 – 5.8 gallons water
4. Next pour lime scale remover into the
bucket – Rydlyme* is an approved scale
remover that is FDA-approved, and
when circulated through the heater for a
period of time, will clean scale and
improve the heater's performance. It is
important to follow the manufacturer's
instructions on the lime scale remover.
* NOTE: It is important to note that
cleaners used that are not compatible
with stainless steel and not FDA-
approved are not recommended and
will void the boiler's warranty.
5. Circulate scale remover through boiler
and flush heat exchanger with clean
potable water.
6. After flushing the heater, remove hose
and close both the inlet and outlet drain
valves securely.
7. Open ball valves slowly and open a hot
water tap water to remove any excess air
that may still be in the heat exchanger.
8. Turn power back on to the boiler and
verify proper operation of boiler.
Boiler Manual