2 dimensions 3 heating system design – Glow-worm Xtrafast 96-120 User Manual

Page 9

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9

2000221595

2 Dimensions

3 Heating System Design

The

XTRAFAST is delivered in three separate

packages:
- the boiler
- the fixing jig
- the flue system

7422

Diagram 5

380

X

890

65

234

Lifting Weight:
51,2 kg

X = 470 (96)
552 (120)

• The

XTRAFAST is compatible with any type of installation.

• Heating surfaces may consist of radiators, convectors or fan
assisted convectors.

• The

XTRAFAST can be piped directly to an underfloor

heating system without the need for a mixing bottle. The
maximum central heating flow temperature can be set to
53

°

C.on the boiler printed circuit board during commissioning.

• Pipe sectional areas shall be determined in accordance with
normal practices, using the output/pressure curve (diagram
4).
The distribution system shall be calculated in accordance
with the output requirements of the actual system, not the
maximum output of the boiler. However, provision shall be
made to ensure sufficient flow so that the temperature difference
between the flow and return pipes be less than or equal to
20

°

C. The minimum flow is 400 l/h.

• The piping system shall be routed so as to avoid any air
pockets and facilitate permanent venting of the installation.
Bleed fittings must be provided at every high point of the
system and on all radiators.

• The total volume of water permitted for the heating system
depends, amongst other things, on the static head in the cold
condition. The expansion vessel on the boiler is pressurised at
0,5 bar (corresponding to a static head of 5 m w.g.) and allows
a maximum system volume of 160 litres for an average
temperature of 75

°

C and a maximum service pressure of 3 bar.

This pressure setting can be modified at commissioning stage
if the static head differs. An additional expansion vessel can be
fitted to the system if required, see diagram 8.2.

• Provision shall be made for a drain valve at the lowest point of
the system.

• Where thermostatic radiator valves are fitted, not all radiators
must be fitted with this type of valve, and in particular, where the
room thermostat is installed.

• In the case of an existing installation, it is ESSENTIAL that the
system is thoroughly flushed prior to installing the new boiler.

Filling the system

A filling device must be provided to fill the system, see diagram
8.2.

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