All heating systems must have suitable controls to achieve comfort conditions, maintain economic operation and to comply with Building Regulations & British Standards.
Underfloor heating systems can be used as the sole heating system or as part of a larger system containing radiators for example.
There are many ways to control an underfloor heating system and the choice of controls depends on the system being installed, the building it is being installed in and the needs of the user.
The Speedfit system can operate with almost any type of heat source, including combination boilers and condensing boilers. Flow temperatures for UFH are generally low (40°C-60°C) compared to radiator systems (70°C-82°C)
Always check the suitability of a boiler with the manufacturer before connecting it to an UFH installation.
Types of Heating Control
Controls for underfloor heating systems are divided into 3 main categories:-
- Water Temperature Controls
- Boiler Controls
- Room Air Temperature Controls
In this guide Speedfit concentrate on the room and air temperature controls, but all types are required to
run an efficient system.
Water Temperature Control
On the Speedfit system, this is achieved mechanically by a water injection valve on the Pump Pack.
As the UFH pump circulates the water the valve constantly monitors the flow temperature via a bypass tube and automatically adjusts the volume of high temperature water from the primary flow into the underfloor pipework to maintain the desired flow temperature.
The system is also protected by a safety overheat thermostat which is pre-wired to the UFH pump and should be set 10-15°C above the flow temperature. If a malfunction occurs, this devise will stop the UFH pump and protect the floors and
pipework from possible damage.
The boiler or heat source should not fire or cycle unless heat is required in a specific part of the system. Known as boiler interlock, this is a requirement under Part L of the Building Regulations. The Speedfit System is designed to provide this facility.
Room / Air Temperature Controls
Room temperature controls are needed to comply with current legislation.
The Building Regulations are very specific on the need to provide independent temperature and time control for each heating zone. The system must only supply heat to a zone when it is calling for heat.
When each zone has reached it desired temperature, normally 20-21°C, a thermostat de-activates, the circuit actuator closes and the flow of water through the pipe is stopped.
Mains Voltage Controls System
The components in the mains voltage control systems have been designed to work with their
respective wiring centres and are not intended to be used with other wiring centres.
- Easy to use
- Easy to install
- Attractive slimline components
Easy to use and install, the new John Guest Mains Voltage Controls offer simple but effective control of up to 8 zones. The UH3 Wiring Centre is the hub of the system. It works either in conjunction with our Touch Screen Time Clock and simple to use Dial Setback Thermostats, or, alternatively, our Programmable Room Thermostats. There is also the ability to use both types of thermostat in the same system.
The UH3 Wiring Centre has a total of 8 heating zones and integrated connections for underfl oor heating zones, boiler, hot water control, Time Clock and the option of a radiator circuit. Having all wiring to one central point makes the UH3 much easier to wire up than a conventional underfloor heating wiring centre.
- JGTM4 Touch Screen Time Clock
- JGUH3 8 Zone Wiring Centre
- JGPRTE Programmable Room Thermostat
- JGPRTHW Programmable Room Thermostat Plus Hot Water
- JGDSSB Dial set back room thermostat
- JGUFHA 240 v Circuit Actuator Valve
Compared to other forms of heating, underfloor heating has a relatively slow response time, taking longer to heat up and cool down than say radiator systems.
In order to reduce running costs and to have realistic heat up and cool down response times, rather than the system being switched off, the temperature setting is reduced by about 4ºC. This is called set back because the system is turned down not off.
With the Speedfit System, set back can be achieved in two ways:
Programmable Room Thermostats can be installed in each zone. They give individual time and temperature control, alternating between daytime and set back temperatures.
Non Programmable Room Thermostats or Digital Room Thermostats have their daytime and set back time controlled centrally, using a Centralised/Plug In System Timer or a Remote System Timer.
The thermostats can be connected into two controllable groups (i.e. upstairs and downstairs), with each group assigned a time channel to govern the times at which they go to set back mode.
Speedfit Manifolds are manufactured from high quality brass to the highest UK and European standards.
A unique feature is that connections to the heating pipes are Speedfit Push Fit, offering much reduced installation time.
Flow and return rails are offset and the angles can be altered, all making for an easy installation.
The manifolds are complete with adjustable flow gauge, drain valve and air bleed valve. They are pre assembled on wall brackets and supplied with screws and plugs.