RM Solar Combi Konverter Solar System Installation Manual - page 4
Before contemplating an installation the installer should check that the combi boiler is capable of
providing domestic hot water at circa 60oC. This might mean operating the appliance at a reduced
flow rate and adjusting the external and internal controls (if possible). The combis instructions or
manufacturers data should also be checked to ensure that the combi will fire under conditions of low flow
and pressures of down to 0.5 bar. Some manufactures provide conversion ‘packs’ for low water pressure
areas and one of these might be required in some circumstances, normally this simply means removing
a flow restrictor.
It is advised that provision is made for a manual isolating switch on the feed to the circulation pump. This
should ideally be supplemented by the time controller provided and thought should be given to the best
position for these devices.
Connections and Pipe work
Where the combi boiler and the cylinder are in fairly close proximity with less than 5 metres of total (flow
plus return) pipe run then 15 mm copper will normally suffice. Once the length exceed this it is generally
required to use 22mm pipe. The pipe work runs should be designed to minimise hydraulic losses with
swept bends etc preferred to elbows.
The hot side (flow) of the circuit should be adequately insulated to minimise any temperature drop
between the combi and the cylinder. The cold feed (return) side of the circuit from the cylinder to the
combi should not be insulated.
The circulation circuit contains domestic hot water which may carry large amounts of dissolved air
and care should be taken to eliminate the possibility of air traps with pipe-work running as far as
possible from the boiler to the cylinder in a horizontal or uphill manner. Where this is not possible then
consideration should be given to automatic air traps or air separation devices.
Fig 3 Typical Installation