LK 810 ThermoMat

LK 810 ThermoMat

This is the answer to those who burn wood or pellets and wonder why you should complement your boiler with a Charging Unit and a storage or accumulator tank.

    Use a Charging Unit in your system prolongs the lifetime of your boiler. Because the Charging Unit cools the boiler with pre-warmed return water, the corrosion in the bottom half of the boiler is reduced drastically.
    A tankless system (direct system) must be started several times per day to maintain heat and that means that it consumes more wood or pellets. When you fit a storage tank and a Charging Unit to your system you can save up to 50% of your costs.
    Anaccumulator tank acts as a buffer or heat bank of hot water that is pumped around the system. The boiler heats the water in the tank, and the hot water is then supplied to the consumers. With an accumulator tank there will be long periods between the times the boiler is fired.
    - E.g. one firing/day with accumulator tank with Use a Charging Unit
    - E.g. two to four firings/day without accumulator tank
    With a storage tank and Use a Charging Unit you do not need to fire up the boiler as often as when the boiler is connected directly to the heating system. You exploit the energy that the fuel liberates significantly better, and create optimum conditions for environmentally sound heating

Why Accumulator Tank?

Working of Accumulator Tank

The function of an accumulator tank is simple and is built around the physical principle that hot water is lighter than cold water. Hot water from the boiler is pumped into the top of the tank, at the same time as cold water is retrieved from the bottom of the tank.

If this process is to function as intended, the boundary between hot and cold water must be sharp. If hot water and cold water are continually mixed, the water temperature will be lower. This means that capacity is reduced – in a worst-case scenario, there will not be enough energy to heat the water for a single shower.

The secret behind the perfect separation is to control the intake of the tank so the separation is not disturbed. The fitting that accomplishes this is called a charging unit, and the market-leading charging unit is the LK 810.


When the boiler starts to fire up, the Charging Unit circulates the water internally in the boiler, so that it rapidly achieves its working temperature and can begin to heat the tank. The Charging Unit then pumps the hot water into the top of the accumulator tank slowly and under full control, so that separation remains optimum.

In addition, LK 810 cools the boiler with preheated return water – hot water from the top of the boiler is diluted with a little cold water from the bottom of the tank.


Buy LK 810 charging unit for efficient wood firing

Charging unit for regulation of charging between the wood-boiler and tank, up to a maximum 60 or 120kW. During firing, the Use a Charging Unit 21 transfers the boiler’s hot water to the tank. This occurs at low speed so that separation takes place. Because the Use a Charging Unit 21 preheats the cold water from the tank, condensation and corrosion are avoided, and the boiler can work at a high and even temperature throughout the firing. This increases the lifetime of the boiler and gives optimum efficiency.

The integrated non-return valve for self-circulation provides extra safety in the event of a power cut, and after fi ring has concluded, the heat that remains in the boiler is automatically transferred to the tank.