Water Underfloor Heating

To calculate how much pipe is required, you will need to divide the area of your room(s) by the pipe spacing you require.

What should be the maximum circuit length?

For 15mm, 16mm and 20mm Pipe:

To avoid excessive temperature and pressure drops, it is recommended that a maximum circuit length of 100m is used.

150mm Pipe Spacing
If you are planning 150mm Pipe Spacing (for high heat loss area such as a conservatories, extensions and external buildings), you will need approximately 6.67m of pipe for each m². With this option, a 100m coil of pipe will cover up to 15m².

200mm Pipe Spacing
If you are planning 200mm (standard pipe spacing for internal well insulated areas) is specified, you will need approximately 5m of pipe for each m². This would mean each 100m circuit will cover up to 20m².


For 12mm Pipe:

To avoid excessive temperature and pressure drops, it is recommended that a maximum circuit length of 80m is used.

150mm Pipe Spacing
If you are planning 150mm Pipe Spacing (for high heat loss area such as a conservatories, extensions and external buildings), you will need approximately 6.67m of pipe for each m². With this option, a 80m coil of pipe will cover up to 12m².

200mm Pipe Spacing (Not recommended, due to low heat output)
If you are planning 200mm (standard pipe spacing for internal well insulated areas) is specified, you will need approximately 5m of pipe for each m². This would mean each 80m circuit will cover up to 16m².

Note: You might need to allow a few extra meters of pipe for feed and return from and  the manifold.

Simply multiply the pipe length by 2. For example; for 100m length of pipe, you will need 200 clips.

An easy way to work this out is to take the area of room you are covering and multiply by 1.5. So if you have a 20m2 room then you will require 20×1.5 clip rails which is 30 clip rails

For the cement boards we would suggest as well as adhesive in addition fix with 35mm diameter washers and suitable screws using approximately 8 fixings per panel.

Instructions for Unjamming a GRUNDFOS UPM3 Pump:

If your GRUNDFOS UPM3 pump has been idle for an extended period, such as during the summer months, it may encounter difficulty running when powered on again due to debris buildup within the pump, hindering the rotor’s movement. Here’s how to address this issue:

  1. Listen for Clicking: Upon attempting to start the pump, you may hear repeated clicking sounds, indicating the pump’s built-in mechanism is trying to free itself.
  2. Attempt Automatic Release: Allow the pump to try freeing itself by listening for the clicking noise. Sometimes, this action alone can resolve the issue.
  3. Manual Intervention: If the pump remains jammed despite the automatic attempts, you may need to manually turn the rotor. Contrary to popular belief, the UPM3 pump can indeed be turned manually.
  4. Locate Pump Head Hole: In the center of the pump head, identify a hole. Insert a long shank CROSS HEAD screwdriver into this hole, positioning the tip onto the rotor shaft.
  5. Engage and Turn: Apply pressure and turn the screwdriver to engage the shaft onto the rotor. Initially, the shaft may turn easily, but it needs to be pushed firmly and turned to fully engage with the rotor. Once engaged, you can turn and free the rotor.
  6. Clean the Pump: If manual intervention fails due to excessive debris, isolate the pump using the valves and easily remove the head for cleaning. Ensure the system water is kept clean, and use a suitable inhibitor in the correct dilution to prevent future issues.
  7. Preventative Measures: To avoid similar problems in the future, consider turning on the pump at regular intervals during periods of inactivity. Alternatively, install controls with a built-in pump exercise function and utilize this feature regularly for optimal pump performance.

By following these steps, you can effectively free a jammed rotor in your GRUNDFOS UPM3 pump and maintain its functionality for smooth operation.

Not always. Underfloor heating (UFH) can function with just an air sensor, but in certain situations, a floor sensor is recommended. The primary reason for installing a floor sensor is to protect your floor coverings from excessive heat, ensuring durability and optimal performance.

Not always. Underfloor heating (UFH) can function with just an air sensor, but in certain situations, a floor sensor is recommended. The primary reason for installing a floor sensor is to protect your floor coverings from excessive heat, ensuring durability and optimal performance.

Heatmiser Specific

You must fit mains cable in accordance to local install regulations. We normally recommend for our 3 amp max units, 3 core plus earth (4 core) 1.5mm cable. 

Chipboard System Installation

To glue the joints of the chipboard overlay together we recommend using our D3 PVA Glue 1KG bottle.

1 Bottle will cover approximate joints for 30m2 of floor area.

The boards should also be glued and screwed to the joists, with 2x 80mm fixings required at each cross section with the joists below (150mm in from either side of the 600mm width). This equates to 12 x 80mm screws per board.

Note: Required number of screws to affix routed chipboard to joist is 12 per board for 400m centre joists, 8 per board for 600mm centre joists.

A box of 200 screws will cover

    • 16 boards for 400mm joist spacing
    • 25 boards for 600 mm joist spacing

 

The cement overlay boards are 1200x800mm and it is advised that you screw down every 150mm using 25mm screws on a grid pattern.

This equates to c48 screws per board

A box of 200 5mm x 25mm screws will cover 4 Resobacker overlay boards

Our 1KG EVA Co-Polymer bottle will cover 5m2 so divide your floor area by this to work out how many bottles you require. Example 50m2 of floor area would required 10 x 1KG bottles of glue.

As you approach 60m2 of floor area its more effective to purchase a 25KG drum of EVA Co-Polymer which covers 125m2

Electric Underfloor Heating

This is the most common question we get and the simple answer is, that the running costs are determined by many different factors so it is difficult to generalise. When the systems are used in a well-insulated building (in line with current building regulations) the running costs are usually very low, the thermostatic control in each room/zone means that you only use just enough energy to maintain your desired room temperature. Based on the default thermostat settings, a 1kw system will cost approximately £0.40 a day, based on an average house with an average level of insulation

Our systems are designed so that the floor surface will feel comfortably warm , but will never get too hot to walk on! The thermostat regulates the floor temperature by turning the system off when the floor gets to the required temperature, then back on as the floor begins to cool – thus keeping a constant temperature. It does this up to 3 times per minute for optimum control and maximum energy efficiency.

In the vast majority of cases the answer will be yes, especially in new, well-insulated properties. The exceptions being old properties with little or no insulation, where you have limited floor space available, such as a small galley kitchen, or a small bathroom. In such cases if may be physically impossible to get enough heat output into a small confined space. If you wish to install a primary heating system in an old poorly insulated property, please contact us for advice.

Yes it can – Using a thermostat controller allows the user full control of the heating system, including the ‘occupied’ temperature, the ‘unoccupied’ temperature and the times of operation using a 7-day/24 hr clock control.

How long it takes to heat the floor will vary, depending on your sub-floor and its insulation. Generally the better the insulation the quicker it will heat up, 30 minutes to an hour on a wooden floor, but it will take longer on an un-insulated concrete floor. However, on concrete floors it will also retain the heat in the concrete and therefore take longer to cool down. The carbon film system is supplied with a thin insulation layer so warm up times will be no more than an hour on any sub-floor. However with tiles, if you lay the cables/cable mats onto un-insulated concrete, it can take several hours to heat up. We therefore recommend that you try to use Varme insulated tile-backer boards wherever possible when installing on an un-insulated concrete floor.

The cables are just 3mm thick and include a built in return so they only need to be connected from one end.

The carbon film itself is less than half a millimetre thick and when combined with our 6mm ‘Depron’ insulating underlay below a wood floor, the total combined thickness of the complete system will raise your floor level by just 6.5mm.(Note in a conservatory or on an un-insulated floor, we recommend a double layer of Depron making the increase in floor height 12.5mm)

The answer to the question is yes it can and the carbon foil has been fitted below thousands of sqm of real wood floors during the last few years and we have had no reported problems of cracking, warping or damage to the floor. However two things you need to consider if using a real wood floor: The installation method, ‘floating’ is best (where the boards are glued/fixed together using the tongue and groove). It is also possible to install the film onto battens at 400 mm centres – please see our Fitting Instructions for details. The other consideration is the moisture content. Wood is a natural product and as long as you chose timber that is fully dried out and has a low moisture content.

(Given directly by a technical advisor from ‘The Tile Association’) There are a lot of chipboard floors around and ideally something else should be done before tiling. Additional plywood is an improvement but current thinking is that 2 layers, with joints lapped, should be used to minimize the possibility of cracking. This would mean putting down say 2 layers of 9 mm each, screw fixed at 300 mm centres. Even use of plywood is not ideal. Another possibility, (better than plywood), would be to put a layer of Varme, Wedi or similar inert tile-backer board down and tile onto that.

Demister Pads