Underfloor Heating- Single Zone System
Pipe distance for concrete floor is c/c 200 mm to c/c 300 mm and for
timber suspended floors c/c 200 mm.
Pipe to be 100 mm from the walls. Always go with flow to the cold spots
first. See hand sketch for typical layout. Max loop length is 110 m.
Max loop length is 110 m. If the pipe comes in a 200 m coil, it is
sometimes much easier to work with the pipe if cut in half, ie 2 pcs of 100
m coils. Also we recommend two people for fitting the pipe, one person that
holds the coil and another person to clip the pipe into the insulation.
Fix the pipe to the insulation with the clips provided. You need
approximate 1 to 2 clips per metre of pipe.
The manifold and control pack should always be located centrally in the
building.
The TP5000 room thermostat timer controls the pump. Note, see system
layout provided in this document for typical layout. Also, see wiring
diagram provided. The system needs to have independent control from the
boiler, ie S-plan system.
Try to use all the pipework supplied. You will usually have waste. The
pipe is marked every metre so you know when it is time to go back to the
manifold. The 50 m and 100 m loops on the hand sketch are only rough
estimations on what you will use.
Pipe is normally not laid under Kitchen and Utility units.
We recommend that you first install the manifold and the control pack as
instructions provided. To fit the pipe to the manifold, cut the pipe end
squarely using the plastic pipe cutter. Re-round the pipe end with the
calibration tool provided, place the nut over the pipe, then the olive and
finally push in the insert into the pipe and then attached to the manifold.
The manifold is normally fitted 1 m above the floor level.
If the pipe is kinked when bending, the pipe should be straightened and
rearranged so that the location of the kink remains in a straight length.
Note the lengths of pipe fitted to each circuit, pipe is marked every
metre.
Note also the room, which each circuit applies.
Prevent people from walking over the pipes, keep tools etc away from the
pipes.
Fill the system as instructions provided. Do not fill from the boiler
filling loop.
It is important to purge the pipework from the boiler to the manifold, to
avoid air being introduced into the underfloor heating system.
Hardwood timber flooring must be conditioned before fixing.
Screed or chipboard flooring should be laid immediately after the pipe
laying to protect the pipe.
Balance the loops as suggested in the instructions.
If the underfloor heating system for some reason makes a noise, then there is probably air in the system. The air can be removed from the end caps on the
manifolds, similar to a radiator system. Make sure that the system is
operated for 24 hours before making any adjustments.
When the system is running make sure that the room thermostats are set at 20
degree C. The pump speed should be on number 3. The mixing valve is normally
set on number 3 for concrete floors and number 4 for timber suspended
floors. If for some reason the rooms are not getting warm, then it is
possible to increase the flow temperature on the mixing valve.
Maximum heat output for underfloor heating systems are 100 W/m2 for concrete
floors and 70 W/m2 for timber suspended floors. For any underfloor heating
system to work efficiently the property needs to be built to current
building regulations. Carpet and underlay should not exceed 2.5 Tog.
If you are using the underfloor heating for a Conservatory, note that it
will extend the time you can use the Conservatory for, not to keep it at 20
degree C all year as the heat losses are higher than 100 W/sqm in a
Conservatory. Usually, this is also the case with radiators.
Condensing boilers are very efficient with underfloor heating. For
combination boilers it is recommended to check with the manufacturer if the
boiler can be fitted with a secondary pump. Sometimes if the project is just
a small flat and the combi boiler is only providing UFH and hot water, it is
possible to have the UFH system without the control unit. There need to be a
safety device on the boiler to prevent the end user from adjusting the flow
temperature above 60 degree C.
Underfloor heating systems can be mixed with conventional radiator systems.
Also note that the underfloor heating system needs to be a complete separate
system , ie the flow and return for the underfloor heating needs to go all
the way back to the boiler. If you do have radiators in your system, we
recommend independent control from the boiler, ie not together with the
underfloor heating. See system layout below.
We recommend a minimum of 50 mm of Polyurethane insulation for the
underfloor heating system. This is very high quality insulation and can be
used for both concrete and timber suspended floor constructions.
Note we do not supply the insulation. Any builders merchant will have
Celotex or Kingspan insulation in stock. The quote is based on clipping the
pipe direct to the insulation board. We do supply pipe clips. We recommend
65 mm of screed on top of the insulation for concrete floors, for timber
suspended floors see website or manual.
The screed must be allowed to dry for a minimum of 4 to 6 weeks before the
heating is operated. As the system is used for the first time, the mixing
valve must be set to minimum setting to let the moisture in the screed to
dry out. The temperature should be increased by two degrees every day until
the mixing valve is set at 45°C. Floorboards must have moisture content
lower than 7 % before they are installed. We do not recommend floorboards
thicker than 25 mm, see website link under technical for more information
about floorboards. Always check with the manufacturers of any floor finish
that it will work with underfloor heating.
For stone and ceramics tiles it is recommended that flexible adhesives and
grout are used. Avoid underlays for carpet with felt and rubber crumb type.
With Vinyl check the vinyl floor manufacturer that it works with underfloor
heating. Laminate flooring should have an expansion gap for movement.
As WC and Bathrooms are very small areas, extra heat might be needed.
Therefore it is standard practice to install towel rails in these areas,
combined with the underfloor heating.