Filter
Top Products
TW2000 WOOD-FIRED BOILER – INSTRUCTION MANUAL
TW2000 10/6/05
17
2.7 Control System
The Kerr TW2000 boiler control system serves the following functions:
1. Maintaining the boiler water temperature by controlling the combustion
air entering the boiler. A double pole, double throw aquastat and the air
damper control this function.
2. Protects the Kerr TW2000 boiler from an overfire by overriding the
home’s thermostat and by putting any excess heat into the living area.
Opening the “normally open by-pass zone valve” and turning on the
circulator accomplish this.
3. To allow the Kerr TW2000 boiler to operate as a gravity heating
system in the event of a power failure, the “normally open by-pass
zone valve” will automatically spring open in a power off situation.
4. Kerr TW2000 boiler “BLOW-DOWN” fire extinguishing system. In the
case of extreme over firing the pressure in the boiler will exceed 30
PSI. When this happens, a relief valve will open and allow steam to
escape into the firebox area, damping the fire. See Fig. TW-9 showing
the fitting for the installation of the fire extinguishing system.
IMPORTANT: Upon completion of the installation, a change over from one fuel to
the other shall not require manual adjustment of any controls other than the
thermostat.
2.8 Wiring
The wiring diagrams for the controls on the Kerr TW2000 boiler are shown in
Figures TW-2, 3, 5, and 6. Do not rewire or change the function of the controls on
an existing boiler when adding a Kerr TW2000 boiler. The electrical systems of
both boilers must be powered from a single branch circuit without exception.
NOTE: Most oil-fired boilers utilize a triple aquastat as shown in Fig. TW-2.
No rewiring is necessary in the oil boiler control.
To install the boiler as a free standing unit see Fig. TW-4, TW-5 and TW-6.
NOTE: The aquastat may be marked “High” and “Low” opposite the diagrams.
The diagrams are correct.
ALL ELECTRICAL WIRING MUST CONFORM TO NATIONAL AND LOCAL
CODES.