ARCA GRA115RO, Установка - Использование - Обслуживание

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3.6. Smokebox and fan
The combustion gas, after having given up energy to the water, accumulates inside the smokebox located at
the rear of the boiler. The smokebox houses the two-speed fan, fitted horizontally and consisting of an
electric motor and impeller. The fan allows easy maintenance, being secured in place using wing nuts.
3.7. Water temperature probe sockets
At the rear of the boiler are two identical sockets, A5 and A7, both with a 1/2" coupling, and have the
following function:
housing for the copper sheath that holds the probes connected to the electronic control panel;
free housing for a second copper sheath or temperature measuring device (thermal relief valve).
3.8. Recirculating pump (anti-condensation)
To minimise the possibility of condensate forming in the wood-fired boiler, a recirculating pump needs to be
installed.
The pump is connected between the outlet (A1) and return (A2) fittings, with the direction of flow
from top down. ARCA supplies a recirculating pump kit as an accessory, including pump, connection piping
and fittings.
For correct boiler operation the recirculating pump must be installed.
THE WARRANTY WILL BE VOID IF
THE RECIRCULATING PUMP IS NOT INSTALLED
3.9. Supply water
For correct operation and safety of the central heating system information must be available on the chemical-
physical characteristics of the system and top-up water. The main problem caused by using very hard water
is fouling of the heat exchange surfaces. It’s well known that high concentrations of calcium and magnesium
carbonates (lime scale) precipitate when heating, forming scale. These lime deposits have low thermal
conductivity and consequently prevent heat exchange, creating localised overheating that weaken the metal
structures, leading to breakage. It’s therefore recommended to adopt water treatment in the following cases:
very hard top-up water (over 20°F)
high capacity (large) systems
frequent topping up due to leaks
frequent filling due to maintenance on the system.
IMPORTANT: if the boiler is used as a replacement in an existing system, this should be washed chemically
beforehand using alkaline dispersants.
3.10. Insulation
The Granola automatic boiler is insulated by a 60 mm thick layer of mineral wool placed in contact with the
boiler body, in turn protected by the outer casing, made from epoxy powder coated steel panels.