Existing combi gas boiler system upgrade with solar thermal system to produce hot water. Backup heater is gas combi boiler.
We installed 2 pcs of solar thermal panels and an unvented horizontal indirect tank as an addition to the existing combi boiler heating system.
- During sunny hours the solar thermal panels warm up the water in the new water tank.
- If the temperature of the water is sufficient (above 45 degrees) then the hot water taps in the house receive the hot water directly from the new tank. If the water is still not hot enough, a motorised valve diverts the preheated water through the existing combi gas boiler to reach the desired temperature.
- To eliminate the risk of scalding when the water in the new tank is too hot, a thermostatic mixing valve has been installed
- To pasteurise the water in the new tank after a week a pasteurization cycle starts: the immersion heater in the new water tank warms up the water to 55 degrees and keeps it there for one hour. This process starts only if one full week has passed when the water was not warmer than 55 degrees for at least one hour. Means that this process happens rarely.
The system is fully MCS compilant.
There was no suitable place for the tank inside the house, this is why we put it in the loft.
We made the hot and cold water pipes in the loft as short as possible to elimintate frost danger. Additionally we hav insulated them.
Panels lifting on the roof
Panels on the roof
Water tank in the loft
Existing combi gas boiler connection
Hydraulic Schematics
