When setback is required, the water temperature to the system should be decreased to provide less heat into the space. tekmar Reset Controls shift the heating curve down in order to provide lower water temperatures when an UnOccupied signal is given to the control. The amount that the heating curve can be shifted is adjustable.
In systems where tenants have control of the space temperature, a central zone control with a temperature Adjustment Range Limit can...
In most hydronic systems there are several heating zones within one cooling zone. Until now, unfortunately, the cooling system was not...
In order to decrease temperature swings and increase boiler efficiency, this function automatically changes the on / off differential of the...
When multiple controls in a single system try to operate the boiler(s) simultaneously, short cycling can occur. For the most efficient...
Many systems, such as radiant heating, use a mixing device to reduce the system supply water temperature. The boiler in these...
The heat up and cool down rate of a boiler depends on how much thermal mass the boiler contains. By knowing...
Most boilers require a minimum supply water temperature in order to prevent corrosion from flue gas condensation. The control should therefore...
A boiler is controlled by turning it on and off. In applications where Outdoor Reset is used, the boiler temperature can...
When a boiler is turned off some heat remains in the mass of the boiler. If the flow through the boiler...
To protect the boiler against flue gas condensation and thermal shock, a mixing device should be used to control the load...
When combining setback with outdoor reset, the morning recovery period can be extremely long. By increasing the supply water temperature after...
A Characterized Heating Curve is a more accurate method of outdoor reset. Each type of terminal unit delivers heat into a...
At extreme cold outdoor temperature, considerable energy can be saved by turning the snow melting system off. With these extreme outdoor...
Most indirect fired DHW tanks require a boiler supply water temperature of at least 180°F (82°C) in order to transfer sufficient...
When DHW priority is used, the water temperature within the heating terminals may have cooled down significantly lower than the boiler...
To ensure that the DHW tank is up to temperature after the DHW Setback period the control must raise the tank...
During DHW operation, the boiler temperature is normally raised above 180°F (82°C). Once the DHW tank is satisfied, the residual heat...
DHW priority allows the DHW tank to recover faster by temporarily suspending the heat supply to the heating system. All of...
If DHW priority is selected then heat to the heating system is stopped during a call for DHW. At cold outdoor...
During the night, or when people are not within the building, energy can be saved by lowering the DHW tank temperature....
This function rotates the firing sequence of a group of staged boilers based on the accumulated running hours of each stage....
The control operates the system components every three days for a few seconds to help prevent corrosion build up and the...
Most boilers have built in safety delays before the burner is allowed to fire. The Fire Delay function allows a boiler...
When multiple boilers are staged and rotated, the last stage can be fixed to fire last. A common application is to...
When multiple boilers are staged and rotated the first boiler can be fixed to be fired first at all times. This...
Floating action is an output used to modulate the position of an actuating motor and mixing valve. Floating Action either provides...
In radiant systems it is common to hear the complaint that the floors are cold. However, one must consider that the...
Heating / Cooling Interlock prevents the system from heating and cooling simultaneously. When the heating Room Temperature Units (RTU) have been...
Most buildings have internal heat gains and losses due to people, passive solar heating, or opening of doors. If only the...
Many boilers or water heaters have two stage burners. The control must therefore stage the operation of the burner by first...
In order to increase the efficiency of a steam system, a Lockout or cool down period before each heating cycle can...
The full range of temperatures required through a heating season can be provided with a non-condensing boiler together with a mixing...
A modulating output provides a signal which is directly proportional to the actuator position required by the control. Common modulating output...
An on / off device, such as a boiler, must be operated with a differential in order to prevent short cycling....
On / Off Injection output is used to operate an on / off device, such as a valve or a pump...
When a setback schedule is in effect, the building experiences delays in dropping down its temperature at the beginning of the...
In order to properly control a hot water heating system, the heat supplied to a building must equal the heat loss...
To provide proper boiler staging and accurate boiler supply temperatures, PID (Proportional, Integral, Derivative) control logic should be used. With PID...
To prevent excessive room temperature swings and offset, PID (Proportional, Integral, Derivative) control logic should be used to control the zone...
Thermostat scheduling allows the room temperature to be automatically setback during the heating season, or set up during the cooling season....
Pulse Width Modulation (PWM) is an on / off action that differs from an on / off differential by changing the...
Radiant Base Load uses Two-Stage operation to speed up the response of a radiant system. The thermostat operates the first stage...
Remote sensing allows the end user to control the indoor temperature of several zones from one central location. Multiple indoor sensors...
A scene is a state that all zones react to. Each zone may be selected to react in a particular way...
Most setpoint loads in a heating system operate year round and often at temperatures above the reset operating temperature. When the...
Setpoint Priority allows the setpoint load to recover faster by temporarily suspending the heat supply to the heating system. All of...
In snow melting systems the slab sensor is normally an inch below the slab surface. When the outdoor temperature suddenly drops,...
Snow melting system deal with extreme temperature differences. Slab protection is provided by limiting the rate of heat transfer into the...
Snow / ice detection is used to automatically start and stop a snow melting system. When there is snow on the...
In systems where snow and ice removal is critical, such as hospital ramps, the pick up time for a snow melting...
In snow melting systems accurate control of the slab surface temperature is required in order to provide an energy efficient system....
When a sudden change of supply water temperature occurs, the heating system is subjected to thermal stresses. This is evident in...
In steam systems the boiler is operated in heating cycles which are dependent on the outdoor temperature. Each heating cycle starts...
Some systems such as radiant floor heating must be maintained below an allowable maximum temperature in order to protect the tubing...
tekmarNet®4 provides the flexibility to install a programmable thermostat to provide a system schedule that other simpler thermostats can share. Up...
To provide proper two staging heating and an accurate room temperature, PID (Proportional, Integral, Derivative) control logic should be used. With...
Variable Speed Output is used to vary the speed of a permanent capacitor, impedance protected pump motor of less than 1/6...
A glycol solution in snow melting systems increases viscosity at colder temperatures. This reduces the system flow rate and heat transfer....
When the slab and outdoor temperatures are warm enough, the snow melting system should automatically turn off. The Warm Weather Cut...
When the outdoor air temperature is warmer than the indoor temperature, no additional heat is required in the building and therefore...
By increasing the supply water temperature during the recovery period before the end of the setback schedule, faster pick up times...
When setback is required, the water temperature to the system should be decreased to provide less heat into the space. tekmar...
Since a Zone Control calculates all the on times of the zones, a Zone Post Purge can be performed. Before the...
In typical zoned systems, the thermostats operate on a stand-alone basis. This means that a zone turns on and off as...