A programmable digital thermostat is a device which controls the operations of a climate control system. A programmable digital thermostat is more accurate, efficient and flexible than an analog thermostat. Digital thermostats have continued to grow in popularity as more consumers become both environmentally and energy conscious.

Both analog and digital thermostats perform the same basic function. Both types of thermostats provide an interface to turn climate control systems on or off. They also allow the user to determine the general temperature range where the heating or cooling system turns on or off. A thermostat eliminates the need to manually turn the climate control system on and off as desired, and can maintain a consistently comfortable interior environment.

The main difference between an analog thermostat and a digital programmable thermostat is that digital technology increases the level of functionality over an analog thermostat. By some estimates, the increased functionality and accuracy of a digital thermostat helps decrease cooling and heating costs by as much as 30 percent over an analog model.

Unlike an analog thermostat, which is only able to set a general temperature range for the climate control system, a programmable thermostat provides the ability to set the system at a specific temperature. A programmable digital thermostat also allows users to set specific start and stop times for the climate control system. With this type of thermostat, users can program the room thermostat to keep the temperature of their home warmer in the morning when they wake up, cooler during the day when no one is home and warmer again in the evening when they get home.

There are three major types of digital programmable thermostats. The first type is known as a seven day thermostat and offers the most flexibility. The seven day thermostat allows the user to program start and stop times with specific temperature settings for each day of the week.

The second major type of digital programmable thermostat is the weekday and weekend model, which is also known as a five and two model. With this type of thermostat, the user is able to create one programming schedule for the five weekdays and one schedule for the two weekend days. The third type of digital thermostat is the five/one/one model, which enables the user to set one program for the five weekdays, one for Saturday and one for Sunday.

A programmable digital thermostat is generally simple to install and can be installed as a “do-it yourself” project. Often times the installation will only require a screwdriver, pencil, drill, and the new thermostat. The exceptions to this are programmable digital thermostats for heat pump systems. Heat pumps require a different type of thermostat than other HVAC systems and should only be installed by a qualified contractor.

Types Of Motorised Valves

Two-Port Valves seals off a section of pipe work when the water has reached the required temperature. 3 way modulating valve isolate the central heating from the hot water circuit.

   Motorized Valves or Control Valves are the means by which timers and thermostats adjust the level of heating. Worn or faulty controls valves can impair the reliability of the system. Replace faulty control valves promptly.

When buying a new valve it is advisable to buy one with the same pattern as the unit you are replacing.

1/ Drain the system. Remove the fuse or central heating circuit MCB at the consumer unit.

2/ The flex from the valve will be wired to an adjacent junction box, which is also connected to the heating system’s other controls. Take the cover off the box and disconnect the wiring for the valve.

3/ Removing the old valve requires cutting through the pipe on each side.

4/ Install the new valve. Bridge the gap with short sections of pipe, complete with joints at each end.

5/ Spring the assembly into place and connect the joints to the old pipe. Tighten the valve cap-nuts.

6/ Connect the valve’s flex to the junction box, then insert the circuit fuse or MCB.

7/ Refill the heating system and check that the valve is working properly.

 How to Replace the Motorized Valve Electric Motor

If a motorized valve ceases to open its electric synchron motor may have failed. Use a mains tester to check whether it is receiving power if it is fit a new motor.

   1/ Switch off the electric supply to the central heating system. (There is no need to drain the system)

2/ Once you have ensured that the power is off, remove the cover and undo the single screw that holds the motor in place.

3/ Open the valve using the manual lever and lift out the motor. Disconnect the two motor wires by cutting off the connectors.

4/ Insert a new Synchron Motor then let the lever spring back to the closed position. Fit and tighten the retaining screw. Strip the ends and connect the wires using the new connectors provided.

5/ Replace the cover and test by turning on the power and running the system.

A fan coil unit (FCU) is a simple device consisting of a heating or cooling coil and fan. It is part of an HVAC system found in residential, commercial, and industrial buildings. Typically a fan coil unit is not connected to ductwork, and is used to control the temperature in the space where it is installed, or serve multiple spaces. It is controlled either by a manual on/off switch or by digital thermostat.

Due to their simplicity, fan coil units are more economic to install than ducted or central heating systems with air handling units. However, they can be noisy because the fan is within the same space. Unit configurations are numerous including horizontal (ceiling mounted) or vertical (floor mounted).

The coil receives hot or cold water from a central plant, and removes or adds heat from the air through heat transfer. Fan coil units can contain their own internal thermostat, or can be wired to operate with a remote thermostat.

Fan coil units circulate hot or cold water through a coil in order to condition a space. The unit gets its hot or cold water from a central plant, or mechanical room containing equipment for removing heat from the central building's closed-loop. The equipment used can consist of machines used to remove heat such as a chiller or a cooling tower and equipment for adding heat to the building's water such as a boiler or a commercial water heater.

Fan coil units are divided into two types: Two (2) pipe fan coil units or Four (4) pipe fan coil units. Two pipe fan coil units have one (1) supply and one (1) return pipe. The supply pipe supplies either cold or hot water to the unit depending on the time of year. Four (4) pipe fan coil units have two (2) supply pipes and two (2) return pipes. This allows either hot or cold water to enter the unit at any given time.