Heaters & heating

Wood stove, sauna heater, heat pump and control unit error codes.

Error codes on the display: ER-03 and other control unit messages

What ER-03 (temperature sensor) means and how to fix it safely, plus ER-01, ER-02 and ER-05, a safe reset procedure and when to call service.

Last updated 2 September 2026

heating

Hot tub not heating or heating slowly: causes and solutions

Find the cause step by step when a hot tub is not heating or heating slowly: wood-fired heater, electric element, heat pump and heat loss. With checklist.

Last updated 2 September 2026

sauna heater

Maintaining the sauna heater and sauna stones

Rinsing, restacking and replacing sauna stones, keeping the wood-fired heater and chimney in order, and using the electric heater safely all year.

Last updated 31 August 2026

wood-fired heater

Using and maintaining your hot tub's wood-fired heater

Firing safely, removing ash, draining the tub via the ball valve and winterising the heater: the usage instructions for internal and external RVS316 heaters.

Last updated 31 August 2026