The invention discloses a premixed closed module gas-fired boiler. The premixed closed module gas-fired boiler comprises an airtight
combustion chamber composed of an upper plate, a face plate, a rear plate and a side plate, and a unit base used for fixing the airtight
combustion chamber; a water inlet and a water outlet arranged on the face plate are connected into a water inlet and a water outlet of a front
divergence water tank through a water inlet pipeline and a water outlet pipeline respectively, wherein the water inlet of the face plate is also connected with a built-in
circulating pump through the water inlet pipeline; a rear
divergence water tank is installed on the surface opposite to the front
divergence water tank, and the front divergence water tank is communicated with the rear divergence water tank through a
metal fin tube
heat exchanger; a
fuel gas connector on the face plate is communicated with a
fuel gas header
pipe; a
fuel gas main valve is installed on the fuel gas header
pipe; a plurality of
branch pipes are connected into the part, behind the valve, of the fuel gas header
pipe in parallel; the
tail ends of the
branch pipes are connected with a group of calandria combustors which are connected in parallel. According to the premixed closed module gas-fired boiler, an
ignition system of the boiler is improved, so that a
combustor, a heat exchange
system and other internal devices of an existing gas-fired boiler are integrated and optimized; an
intelligent control system is matched with the boiler for use, so that
internal friction of the boiler is reduced, the
automation degree of the boiler is increased, and
thermal efficiency of the boiler is improved.