TSDR – MFS TECHNOLOGY – for vented water heating applications

This product is part of ROD/STEM THERMOSTATS
Relevant applications:


Rod combination thermostat with 1-pole temperature regulation and 1-pole MFS safety limiter.



  • Patented in rod MFS technology
  • Over temperature cut out
  • Ensures compliance with clauses 19 & 22 of EN 60335-2-73 for fixed immersion heaters
  • Independent non self resetting safety option
  • Accurate and adjustable temperature control
  • Direct replacement for non-compliant immersion thermostats



The differential expansion of the sensing element causes the opening of a snap-action switch in the thermostat head.  In case of abnormal temperature rise, the patented MFS technology ensures single pole safety operation.  The limiter is manually resettable.

Technical characteristics
  • TSDR
Type Single pole stem control with single pole MFS technology safety limiter
Temperature range 0 to 65°c / 32 to 149°F
Safety limiter temperature Fixed 60 to 90°C / 140 to 194°F
Rating 20A - 250V / 15A - 400V
Material Brass, invar, MFS
Stem length Up to 450mm / Up to 18"
Connections Pillar terminals
Approvals CE conformity, ENEC mark according to EN-60730-1, EN 60730-2-9, ROHS conformity
Technical drawings