Tetra installs two kinds of boilers

Gas Boilers
Gas boilers are fueled by either natural gas or propane, and they are highly efficient. The water heated by your gas boiler provides central heating and hot water for your home. There are 2 styles of gas boilers: traditional tank boilers and combination boilers. Traditional tank boilers heat a tank of hot water for use in the home, and combination boilers heat water on demand.

Combination Gas Boilers
Combination gas boilers, also known as combi boilers, combine a hot water tank and boiler into a single high-efficiency unit. These gas boilers provide your home with both hot water and central heating. A combination boiler heats water directly from the water main, as you need it, so there’s no need for water storage tanks. Combi boilers are highly efficient and very compact, so they’re great for smaller homes.