Page 5
DESIGN
INTR
ODUCTION
The Building Regulations L1A: New dwellings/L1B: Existing dwellings and the
requirements set out in the Domestic Heating Compliance Guide specify that “where
the mains water hardness exceeds 200ppm provision should be made to treat the feed
water to water heaters and the hot water circuit of combination boilers to reduce the
rate of accumulation of lime scale”.
To comply with this requirement the hardness of the mains water should be checked
by the installer and if necessary the optional factory fitted electronic in-line scale
inhibitor should be specified at the time of order for hardness levels between 200
and 300 ppm (mg/l).
Where the water is very hard ie 300ppm (mg/l) and above the optional polyphosphate
type, inhibitor should be specified at the time of order. However, this will need to be
fitted by the installer at a suitable point in the cold water supply to the appliance.
If scale should ever become a problem the plate heat exchanger is easily isolated and
quickly replaced with a service exchange unit which can be obtained at a nominal
cost from Gledhill.
The controller built into the BoilerMate A-Class OV SOL appliance automatically opens
the 2 port valves fitted in the boiler return to allow the maximum possible energy
input to be provided from the solar collectors whilst ensuring that at times of low solar
gain/peak use the boiler is automatically energised to boost the store temperature to
ensure customer satisfaction. The solar pump speed is also modulated, which alters
the flow rate and allows it to extract the maximum amount of heat possible from the
solar collectors.
The built in controller also incorporates the facility to operate the heating pump for
a few seconds every few days when the heating is not being used (to reduce the
likelihood of the pumps sticking) as well as providing a boiler pump overrun facility.
Any automatic boiler designed to operate on an 82°C flow and a 71°C return up to
a maximum of 35kW can be linked to any suitable model of BoilerMate A-Class OV
SOL and the deciding factor is the space heating and the hot water requirements
of a dwelling. See the Technical Data section in these instructions for further details.
The BoilerMate A-Class OV SOL is supplied complete with ‘Switch’ which will provide
a 6kW electrical emergency backup in case of failure of the main heat source. See
page 21 for further information.
If a summer towel rail circuit is required, this will need to be a separate zoned circuit
from the heating circuit complete with its own time and temperature controls.
The heat losses from thermal stores should not be directly compared with heat losses
from unvented or vented cylinders because they are treated differently in SAP. The
SAP calculator takes account of the type of store and various correction factors are
included to reflect the different ways that the hot water and heating operates.
For further information please request a copy of the SAP 2005 Data Sheet which
provides the information required to produce SAP calculations for all Gledhill Thermal
Storage products.
Gledhill are part of the ‘Benchmark’ scheme and a separate commissioning/service
log book is included with the product.
Note
The BoilerMate A-Class OV SOL is a SYSTEM appliance and only requires a
basic boiler. If a system boiler is chosen this will present wiring/operational
difficulties as well as incurring extra costs.
