Hot tub heater - What to consider when heating the hot tub | Kirami
Improve hot tubbing safety with Kirami products


Q: What are the required fire safety distances for the heater and the chimney?

A: The fire chamber of the heater is surrounded by a water jacket. This means that the temperature of the heater will not exceed the temperature of the water inside the heater. However, there needs to be a non-flammable protector in front of the fire chamber in case sparks or embers drop out of the chamber. Our selection of accessories includes a fireproof plate to protect the front of the fire chamber. As for chimneys, please refer to the fire safety distances presented in our instructions. 

Q: Is a heater that is placed inside the tub more efficient than an external heater?

A: Almost all external heaters are more efficient than internal models. An external heater is considerably more user-friendly than an internal model, and it also saves bathing space. 

Q: Does the heater become hot?

A: The external surface of the heater will only become as hot as the bathwater. However, please note that the chimney and the heater door become hotter than the bathwater, as they are not in direct contact with the water.

Q: Does the heater require soot removal?

A: The internal walls and pipes of the heater must be cleaned of soot when necessary. If you use a chimney cap with a spark catcher, it should also be cleaned every now and then to ensure a good draught.

Q: How often should I empty the ashes?

A: The ashes must be emptied after every heating to prevent the grates from burning out prematurely and to ensure a good draught while heating.

Q: There is humidity inside the heater. Is the heater broken?

A: The temperature difference between cold water and warm, humid air causes condensation inside the ash compartment, so there are probably no leaks in the heater even if there is some humidity inside the fire chamber. Considerable condensation may occur when you light a fire, but if the water level in the tub does not change, there are no leaks.

Q: The heater has lost some of its efficiency and the heating takes longer than usual. What should I do?

A: You should empty the coals and ashes from the fire chamber and clean the grates. We also recommend cleaning the chamber with Kirami Nokipesu. Soot accumulates on the walls of the fire chamber over time, reducing the heat conductivity. Nokipesu enables you to easily remove even the most stubborn soot deposits.

Q: How can I reduce the amount of smoke?

A: Use suitably small, dry and clean firewood. Be sure to also maintain as large a fire as possible and make sure that the firewood is not packed too tightly in the chamber. If your heater features adjustable air intakes, experiment to find the optimal supply of make-up air. One alternative is to use Kirami Heat It Up wood charcoal, which burns at a high temperature and cleanly without visible smoke.

Q: The instructions mention a new ash box. Where can I get one?

A: The ash box is an accessory that you can order from a retailer or on the Kirami web store.

Q: How can I reduce the amount of sparks?

A: If sparks are causing you trouble, we recommend using our spark shield. When you use birch or better wood, the amount of sparks exiting the chimney is very minimal, in which case a conventional chimney cap will suffice. Using other kinds of wood (pine, spruce, waste wood) will cause more sparks, and when this poses a threat to safety, we recommend using a spark shield, which minimises the amount of sparks released into the environment. Like a conventional chimney cap, the spark shield also protects the chimney from rain. During dry seasons, or if there is a risk of the sparks igniting something, you should practice caution and use firewood that does not cause sparks. Never leave the fire unsupervised.

Q: Can I install a pump between the hot tub and the heater?

A: This is prohibited, as the heaters are only designed for the natural water flow, and using a pump would cause the pressure inside the heater to increase. Starting and stopping the pump creates pressure shocks inside the heater that could break the heater.

Q: What is a magnesium anode rod and what are the advantages of it?

A: Kirami’s magnesium anode rod protects your heater from corrosion that chlorine and sea water can cause. The rod should be checked annually and replaced when necessary.

Kirami anode rod | New vs old used anode rod | Kirami
Kirami anode rod - new vs old used anode rod

Q: Why the stove does not have an air grid?

A: Cult and Macu stoves do not have an air grid as a standard. At the beginning of 2018, a place for a grid has been added on the hatch. There is now a possibility to buy and install the grid for those stoves as an accessory. The air grid helps, for example, to start the fire in windy conditions. To get the maximum power from the combustion the grid must be fully open. When you wish to slow down the combustion, you can diminish the opening.

Enjoy the perfect bathing time! Discover our wide range of accessories and learn more about Kirami's various hot tub models!