Is it possible to run different system types from a single manifold?
Yes. It is possible to run differing system types such as solid, suspended, Overlay and Overlay Lite systems from the same manifold. However, care should be taken to ensure that the system flow temperature, as set at the manifold mixing valve, is suitable for use with all of the system types.
Can a zonal regulation unit (ZRU) be used as a ‘stand alone’ system and be operated separately from the main heating system?
Yes. If the primary flow and return pipes from the ZRU are taken back to the boiler and connected in to the main primary pipe work prior to any existing zone valves, then it will be possible to operate this zone independently. Of course, it will also be necessary to add a two-port motorised zone valve to this ZRU primary circuit.
Can the Underfloor Heating system be used to accelerate the drying out time of the screed?
No. Under no circumstances should this be done as it could lead to irreparable damage to the screed product.
Can I add an inhibitor to the Underfloor Heating system?
Yes. Our polybutylene pipe is compatible with most domestic inhibitor products but if you are unsure about the suitability of a particular product with plastic piping systems then please consult the inhibitor manufacturer.
Can the Underfloor Heating system be tested with air?
We do not recommend that an air test be used to pressure test the system due to safety reasons. Instead, the system should be water tested to a maximum of 6Bar for no less than 30 minutes and no longer than one hour.
When installing Underfloor Heating within a ‘sealed’ heating system will I need to fit an additional expansion vessel?
This will all depend upon the size of the existing expansion vessel. Most system boilers will have a 10ltr expansion vessel fitted which will be able to accommodate systems with a water content of approximately 130ltrs. If you are only adding a single room of underfloor heating to the system, this expansion capacity may be sufficient. However, if the underfloor heating installation is to be several rooms you may need to add another suitably sized expansion vessel to the system. Please refer to the relevant section of the boiler installation manual or seek technical guidance from the boiler manufacturers.
What is the recommended screed depth when installing Underfloor Heating?
When using a typical sand and cement screed product the recommended depth for most domestic applications is 65mm. However, with some liquid anhydrite screed products this depth can sometimes be reduced to 50mm. For further information, please refer to the BSRIA guide ‘Screeds with Underfloor Heating’.
Is a Y plan system configuration suitable for an underfloor heating installation?
No. Because of the unique hydraulic operation of a ‘Y’ Plan (also known as mid-position or flowshare valve) it is not suitable for use in a mixed central heating installation where a radiator circuit and an underfloor heating circuit are to be installed. Instead, the system should be designed or adapted to either an ‘S’ Plan or ‘S’ Plan Plus system where individual two-port motorised zone valves are used to control each primary circuit.
What are the benefits of using a ‘spiral’ pipe configuration over a standard ‘serpentine’ pattern?
As with any heating installation a temperature drop will occur across the system as the water is being circulated around the various circuits. This temperature drop, which in some cases may be as much as 10°C, will gradually increase as the water passes through the circuit/s which in turn means that the heat input into the floor from the system will also be reduced as the water reaches the furthest part of the room. However, in a ‘spiral’ pipe configuration because the flow and return pipes are alternated across the entire circuit, the effect of this temperature drop is far less pronounced thereby making for a better heat distribution across the room.
Do I need to install an additional layer of insulation below the Underfloor Heating system?
It is a requirement of Building Regulations (BS EN1264 1-4), that when constructing a new solid floor it is necessary to provide a layer of insulation below the screed. This is required regardless of whether an underfloor heating system is present. This layer of insulation aids the efficiency of a ‘solid’ floor underfloor heating system (where the pipes are buried in screed) as it minimises any downward heat losses to less than 10W/m².
When using our Overlay system, there is no need for additional insulation as the overlay panels already contain all the necessary insulation.