The GXV Xcel a superb all-round performance system, originally designed as a compact, high output hot water and heating system for council properties. To obtain 100% useful input from the boiler, the store
is heated directly by the boiler - no coils. A feed and expansion tank must be
fitted above the highest point in the primary system. The main advantages of the system are...
No Motorised Valves for either hot water or heating - more reliable & easier
to service.
Very rapid recovery of store - hot water in under 3 minutes from cold.
Large volumes of hot water from a small store.
Maintains condensing boilers in condensing mode.
Ability to bring central heating up to temperature extremely quickly (store
recovered).
Store acts as an ideal air separator. |
| The Flow Switch is fitted with a 22mm By-Pass. This can be used to reduce the mains pressure drop accross the unit. The valve should be balanced so that the Heat Exchanger Pump [3] switches on at the minimum hot water flow rate. |
 With
Grundfos Alpha installing the
circulation pump has become more convenient and easier than ever before.
You simply plug and pump. Without even having to open the terminal box! Being automatic the pump itself applies the
pressure and flow required by the system – regardless of the building
or the time of year. And there’s noticeably less noise from pipes and
radiators.
Grundfos Alpha has automatic control, which
ensures that the pump’s pressure and flow is constantly adjusted to
meet current needs - summer or winter, night or day.
An old-fashioned circulation pump pumps at
the same power 24 hours a day – every day.
The automatic control ensures that the pump
can “talk” with the heating system’s thermostats. When the heating
is turned up the pump is hard at work. When the heating is turned down
the pump works correspondingly less.
The improved balance between the pressure
and flow produced by the pump and the throughput allowed by the
thermostats also means reduced noise. |
  The unit is fitted with a Mixcall III Thermostatic Blending Valve, to control
the hot water temperature, and prevent scalding. The graph shows the pressure drop across the valve for various hot water flow rates.
The Valve is adjustable from 27°C to 67°C, and has a lockable
head. |
| The unit is fitted with two heat exchangers, and is capable of delivering 45 litres/minute @45°C (80°C storage). |
| A Mains Water Isolating Lever Valve must be fitted within the cylinder cupboard, in clear view and easily accessible. A Strainer (supplied loose) must also be fitted, down stream of the isolating valve, to protect the flow switch [4]. |
| It is advised that the mains water is tested for hardness. In areas of hard water, we advise the use of a scale inhibitor. |
| It is important that SENTINEL X100 Inhibitor is used to protect the Heat Bank Thermal Store.
Use 1 litre per 100 litres of stored water. A suitable anti-freeze, such as X500, should also be added when there is a chance that the unit will be left filled and unheated in freezing conditions.
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