Installation & Operation Manual
8 Domestic water heaters
This section applies only to those appliances used to supply domestic hot water, installed with a storage tank(s). A circulating pump MUST be installed in the piping assembly to the storage tank and valves used to control water velocity through the appliance. Proper water velocity is important for correct operation of your water heater.
This section contains specific instructions for those appliances used to supply domestic hot water. All warnings, cautions, notes and instructions in the general installation and operation sections apply to these instructions. Water heaters are designed for installation with a storage tank. The operation of the circulating pump, proper sizing of the piping between the tank and heater and the control of water velocity, as explained in this section, are important for correct operation of your water heater.
NOTICE | To ensure proper velocity through the heat |
exchanger, it is necessary to regulate the | |
| temperature rise across the heat exchanger |
| from inlet to outlet. This must be done |
| on initial installation and periodically |
| rechecked. With the correct temperature |
| rise across the heat exchanger when the |
| water heater is firing at 100% of rated |
| input, you may be assured of the proper |
| velocity in the tubes. This will yield long life |
| and economical operation from your water |
| heater. |
Excessive lime/scale
Initial
On initial
TABLE - 8A
MAXIMUM WATER FLOW
CAUTION: The maximum flow rate through a
Model | Maximum Flow |
|
|
402, 502, 652, and 752 | 55 GPM |
|
|
992, 1262, 1442, 1802, and 2072 | 90 GPM |
|
|
If higher flow rates are required through the water heater, an optional Cupro Nickel heat exchanger is available. Consult the factory for specific application requirements.
The heat exchanger is capable of operating within the design flow rates required for the water heater, storage tank(s), and connecting piping. Erosion of the finned copper tubes may occur if the flow rate exceeds the maximum allowable flow rate through the water heater. The maximum flow rate through the water heater must be adjusted. Maximum flow on Models 402
-752 is 55 GPM and 90 GPM on Models 992 - 2072. Flow rate can be determined by measuring the temperature rise through the water heater when it is firing at full rate input.
TABLE - 8B
TEMPERATURE RISE AT FULL RATE FIRE
55 AND 90 GPM FLOW
Model | Temperature Rise °F |
402 | 12 |
502 | 15 |
652 | 20 |
752 | 23 |
992 | 19 |
1262 | 24 |
1442 | 27 |
1802 | 34 |
2072 | 39 |
1.The pump must run continuously when the burner is firing.
2.With the pump running and the burner in the water heater in the off cycle, the inlet water temperature and outlet water temperature readings on the Operator Interface should read approximately the same temperatures. Water Temperature Rise on the Operator Interface should read near zero.
3.Turn the water heater on and allow time for the temperature to stabilize. The Service Mode can be used to force the water heater to run at full fire. See the
4.Compare the water temperature rise in the Operator Interface with the required temperature rise. Should adjustment be needed, proceed as follows.
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