HTP 399M - Manual (Page 69)

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
Inspect the interior of the boiler jacket area; clean and vacuum if necessary.

Clean the condensate trap and fill with fresh water.

Check for water, gas, flue and condensate leaks.

Verify flue vent piping and air inlet piping are in good condition, properly supported, and tightly sealed.

Check boiler water pressure, piping and expansion tank.

Check control settings.

Check ignition electrode. Sand off any white oxide. Clean and reposition.

Check ignition and ground wiring.

Check all control wiring and connections.

Check burner flame pattern (stable and uniform).
Additional Items if Combustion or Performance is Poor

Clean heat exchanger and flue ways.

Remove burner assembly and clean burner head using compressed air only.
Once the maintenance items are completed, review service with the owner.
C. COMBUSTION CHAMBER COIL CLEANING INSTRUCTIONS
*Before beginning this procedure, you must have on hand the following items:

A nylon, stainless or brass brush (not steel)

A liquid calcium and lime deposit remover

Gloves, eye protection
1. Shut down the boiler by using the following steps:
a. Close the gas valve, shut down the unit and wait for the unit to be cool to the touch.
b. Disconnect the condensate hose from the outside connection, (not from the boiler side), so flow can be observed.
c. Disconnect connections from the gas valve, spark electrode and flame rectification probe and combustion blower.
d. Remove the (4) screws on the aluminum ½” NPT connector on the gas valve.
e. Disconnect the wiring connected to the combustion blower motor.
f. Remove the (6) 10MM nuts from the burner plate assembly to access the coils.
g. Pull the entire burner plate assembly with blower still attached towards you, while removing or pushing aside any wiring to
allow the removal of the assembly.
2. Using a spray bottle filled with calcium and lime deposit remover, spray liberally on the coils, making sure the solution penetrates and
funnels down through the condensate hose. If the condensate hose is blocked, let the chemical penetrate for at least 15 minutes or until
it drains.
3. Use the nylon, stainless or brass brush (do not use steel) and scrub coils to remove any buildup. Then vacuum the debris from the
coils. WARNING: Follow above precautions.
4. Spray the coils with clear water, making sure to confine the spray to the area being cleaned (try to avoid getting the back ceramic
wall of the unit wet). Flush the combustion chamber with fresh water. At this point, the boiler should be ready to power back up.
Before powering up the boiler follow the steps below:
a. Re-install the burner assembly.
b. Replace the (6) 10MM nuts to the burner plate.
c. Re-connect all wiring connections.
e. Replace the (4) screws on the aluminum ½” NPT connector on the gas valve. Turn the gas back on. (IMPORTANT: CHECK
FOR GAS LEAKS.)
f. Re-set thermostats (IMPORTANT: MAKE SURE EXHAUST VENT IS NO LONGER BLOCKED!)
g. Turn the boiler back on and observe condensate flow.
h. Re-connect the condensate hose to the outside connection.
Do not use solvents to clean any of the burner components. The components could be damaged, resulting in unreliable or unsafe
operation. Failure to do so could result in death or serious injury.