AERCO SmartPlate - Manual (Page 43)

SmartPlate Installation, Operation & Maintenance Manual
CHAPTER 6 – SCHEDULED MAINTENANCE
OMM-0069_0E AERCO International, Inc.  100 Oritani Dr.  Blauvelt, NY 10913 Page 43 of 138
SP-100 Phone: 800-526-0288 PRI: 11/26/2013
WARNING
PRIOR TO PERFORMING THE FOLLOWING STEPS, ENSURE
THAT THE POWER SWITCH ON THE SIDE ECS/SP CONTROL
BOX IS OFF AND THE HEATER HAS BEEN DRAINED AS
SPECIFIED IN THE PREVIOUS PARAGRAPH.
1. Make sure that the POWER switch on the Control Box is OFF.
2. Ensure that the Drain Valve is open and the water has been drained from the unit.
3. Locate the Recirculation Pump and disconnect the flanges from the piping.
4. Carefully slide the Pump out and rotate to inspect. DO NOT pull on the electrical conduit
when removing Pump.
5. If there is evidence of scale build-up, disconnect the conduit and electrical power
connections from the Pump. Service or replace the Pump as necessary.
6. If there is no evidence of scale build-up on the Recirculation Pump, reinstall the Pump and
reconnect the flanges.
6.9 PERIODIC CLEANING OF HEAT EXCHANGER
It may be necessary to de-scale the heat exchanger periodically, depending on water conditions
and temperature settings. Paragraph 8.2 describes the descaling process for the SmartPlate
heat exchanger.
The frequency of cleaning can be determined locally based on the performance of the heater
and/or prior experience with similar equipment. Generally, the cleaning requirements will follow
the trends shown in Table 6-2 which follows:
Table 6-2. Heat Exchanger Cleaning Guidelines
Operating Conditions
Projected Cleaning Frequency
Rarely Annually
Semi-
Annually Monthly
Boiler Water Inlet Temp <150ºF ~170ºF ~200ºF ~220ºF
Domestic Water
Setpoint
<130ºF 140 - 160ºF 160 - 180ºF
Calcium Hardness Level <20 mg/L 20 - 40 mg/L 40 - 60 mg/L >80 mg/L
If calcium hardness level, boiler water inlet temperature, and domestic water setpoint fall under
different cleaning frequency in Table 6-2, it means the heat exchanger may be cleaned between
those periods. It is recommended to follow the most frequent period to start with. Observe the
next few cleanings on how much scale is removed to determine if less frequent period can be
followed.