Thermal Safety Valve


98.00 ex. VAT

This thermal safety valve prevents excess temperatures in solid fuel fired boilers in water-based closed circuit heating systems. Internally threaded inlet connection, DN20.

Lead Time: 3-4 weeks

  • Description
  • Specifrications
  • Technical Documentation



The thermal safety valve series VST100 prevents excess temperatures in solid fuel fired boilers in water-based closed circuit heating systems, in accordance with EN12828. Heating capacities of up to a maximum of 100
kW are allowed for these systems. It is indispensable to install a thermal safety valve in systems in which the heat generating device is equipped with a water heater. The thermal safety valve series VST100 is a pressure relieved single-seated valve that opens in case of rising temperature. It is controlled by means of two independent temperature transmitters. The compact temperature transmitter can be removed to facilitate the assembly of the valve. A metal hose coating prevents any damages on the capillary tubes from the sensor to the transmitter. The length of the capillary tubes is 1.3m. The thermal safety valves carry CE-marking, according
to the European directive PED 2014/68/EU.


Install the thermal safety valve preferably in the cold water inlet of the safety heat exchanger. This type of installation protects the valve against impurities due to limescale deposits or similar effects. Install the valve in the warm water outlet only in the case of older boiler models where the protection is provided by an integrated potable water heater without temperature control. The boiler is indirectly cooled down by the cold water flowing into the potable water heater, which prevents the temperature from exceeding the admissible maximum of 115°C. The valve might be mounted in any position. It is recommended to install a potable water filter in order to ensure perfect and durable functionality. Note that this is mandatory in some countries. The warranty is not applicable when the malfunction of the valve is caused by dirt.

Service and Maintenence

For control of its functionality, the thermal safety valve might be flushed manually. When necessary the valve can be opened and seat and seal might be cleaned. Cleaning the seat and seal does not
change the temperature setting.


Operating conditions

Pressure class: PN 10
Temperature: max. +125°C


Opening temperature: 95°C +0/-4°C
Boiler heat capacity: max. 100 kW
Length of capillary tube: 1.3m
Valve connection: Internal thread (G), ISO 228/1
Immersion pocket connection: External thread (G), ISO 228/1


Valve housing and other metal parts with fluid contact: Brass CW 614N

Acc. to PED 2014/68/EU, IV and standards EN 14597, VdTÜVMerkblatt Temperatur 100

Technical Documentation

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