Operation, Filling the Tank | Thermo Products manual

Section 4 : Operation

!SAFETY PRECAUTIONS

Before operating this water heater, be sure to read and follow these instructions, as well as the warnings printed in this manual. Failure to do so can result in unsafe operation of the water heater resulting in property damage, bodily injury, or death. Should you have any problems reading, following or difficulty in understanding the instructions in this manual, STOP, and get help from a qualified person.

Do not turn on the water heater unless it is filled with water. Do not turn on water heater if cold water supply shut-off valve is closed.

Once the plumbing and electrical connections are completed, your COMBOMAXMC unit is ready for automatic operation.

4.1 FILLING THE TANK

Open the outlet valve (in a zone valve system, manually open the zone valves).

Open the boiler inlet valve. Bleed the air from the boiler tank by opening the safety valve atop the boiler while you are filling the tank.

Leave all valves open. Reset the zone valves to automatic operation. Check for leaks and repair if necessary.

Bleed the air from all zones if required. Check the boiler pressure gauge. A pressure reading between 15 and 20 psi is normal for most installations.

4.2FILLING THE HEATING COIL

Make sure all drain cocks are closed.

Open the nearest domestic hot water tap as well as any control valve on the water heater outlet (the copper tube atop the boiler).

Open the cold water inlet valve on the heater inlet tube. (the copper tube on the left side of the unit).

Close the domestic hot water tap as soon as water flows out of it. Fix any leaks

Open all other hot water taps fed by this heating coil to bleed the air trapped behind them.

4.3 ADJUSTING THE AQUASTATS

Once all air has been bled from the system and all components (valves, bleeders, controls) have been properly adjusted, the boiler can be put into operation. Never operate the boiler before these adjustments are complete.

Bear in mind safety and energy-saving considerations when adjusting the boiler water temperature with the aquastats. It is most energy-efficient to set them as low as possible, in a manner consistent with your heating needs.

However, a minimum temperature of 160°F is recommended for domestic hot water production.

Each aquastat controls a boiler stage (in the 240V model, each element has its own aquastat). Adjust the setting of each aquastat by turning the dial scaled in degrees Celsius and Fahrenheit. See figure 10 for aquastat identification.

Set the first aquastat to the highest outlet temperature required by the heating system. Thermo 2000 inc. recommends a setting of 180°F.

Adjust the second aquastat 1°F to 20°F below the first aquastat setting. Usually, a setting 5°F below that of the first aquastat, or 175°F, provides good results in a system designed for a 20°F temperature drop between the tank inlet and outlet.

Proceed in a similar manner for the 3rd and 4th aquastats, which will result in settings of 170°F and 165°F. Thus, the number of elements in operation will increase (or decrease) according to the settings and the drop (or rise) in the heating water temperature.

The domestic hot water priority aquastat should be adjusted to a setting 5oF below that of the last stage or 4th aquastat, i.e., 160°F.

At system start-up (on the first heating day of the season), ìt may take quite some time for the boiler water to reach its operating temperature. Check the thermo manometer.

COMBOMAXMC Electric boiler Set-up, use and care guide (revised January 2006), Page 10.