Mikrofill Ethos RS 350, Техническая документация инструкция

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INSTALLATION
20 TECHNICAL DOCUMENTATION
SHUT-OFF VALVES
It is recommended that manual valves should be installed between the flow and return connections to the
installation.
VALVES (BOILERS IN CASCADE ARRANGEMENT)
To prevent water flow through non-firing boilers, and hence unnecessary heat loss, a spring loaded non-return
valve may be installed on the return pipework external to the boiler.
DRAINING AND CLEANING
To drain and clean the boiler, a drain valve must be installed between the boiler and the first valve. Isolate the
water and electrical supplies to the boiler and open the drain valve. As there is an automatic air vent on the
boiler the water will drain naturally. Please note the bottom coils will not drain fully and water will remain. To
clean the water side of the boiler a suitable descaler / desludger can be used. Please contact our technical
department on 03452 60 60 20 for further information.
WATER CIRCULATION SYSTEM
A circulation pump MUST be connected to the boiler and the hot water cylinder MUST be of the indirect type.
The boiler MUST NOT be used for direct hot water supply, and single feed, indirect cylinders are not
recommended and MUST NOT be used on sealed systems. The appliance is NOT suitable for gravity central
heating nor are they suitable for the provision of domestic hot water.
The hot water cylinder and ancillary pipework, not forming part of the useful heating surface, should be
lagged to prevent heat loss and any possible freezing, particularly where pipes run through roof spaces and
ventilated underfloor spaces. The boiler must be vented and there must be no low points between the boiler
flow connection and a system venting point, which should be positioned as close to the boiler flow
connection as is possible.
Draining taps MUST be located in accessible positions, which permit the draining of the whole system,
including the boiler and hot water storage vessel. They should be at least ½” BSP nominal size and be in
accordance with BS2879. Do not use the boiler drain tap to drain the system as this can induce sludge into the
heat exchanger.
The central heating system should be in accordance with the relevant standards listed on page 07.
Due to the compact nature of the boiler, the heat stored within the heat exchanger at the point of shutdown
of the burner must be dissipated into the water circuit in order to avoid overheating. In order to allow pump
operation after shutdown, the boiler incorporates a five minute pump overrun facility. In order to make use of
this, the pump must be supplied from the terminals inside the boiler. Please note that for pumps requiring
greater than 1.0 amp current, they must be connected via a relay / contactor. When sizing pumps, reference
should be made to the hydraulic resistance table on page 19 which shows the boiler resistance against flow
rates, to achieve the required temperature differential.
With the boiler firing at maximum rate, the temperature differential should not be less than 10°C. With the
boiler firing at minimum rate, the temperature differential should not be more than 35°C. Lower flow rates
generating higher temperature differentials may lead to lockouts of the boiler. The lower the return
temperature to the boiler, the higher the efficiency. At return temperatures of 55°C and below, the difference
becomes marked because the water in the flue gases starts to condense, releasing its latent heat.
In installations where all radiators have been provided with thermostatic radiator valves, it is essential that
water circulation through the boiler is guaranteed. A low loss header will perform this task.