The Caleffi F29633 is a replacement thermostatic cartridge rated 115 F for Caleffi Series 280 ThermoProtec and Series 281 ThermoBloc units. It is a service part installed into an existing valve body and is not a complete valve.
Best for re-rating an installed ThermoProtec valve to a different return temperature, or renewing a worn element.
Specifications sourced from Caleffi North America technical literature. Last reviewed July 2026.
Key Features
Rated 115 F Set Point
Factory-calibrated to 115 F, allowing an installed ThermoProtec valve to be reset to a different return temperature without replacing the body.
Service Part, Not a Complete Valve
Supplied as the internal thermostatic element only. It installs into a Caleffi Series 280 ThermoProtec or Series 281 ThermoBloc body already in the piping.
Technical Specifications
| Product Type | Replacement Thermostatic Cartridge |
| Application | Biomass |
| Compatibility | Caleffi Series 280 ThermoProtec and Series 281 ThermoBloc |
| Rated Set Point | 115 F |
Related Products
- Caleffi F29634 : Thermostatic Cartridge 130 F
- Caleffi F29635 : Thermostatic Cartridge 140 F
- Caleffi F29636 : Thermostatic Cartridge 160 F
- Caleffi 280165A : ThermoProtec Anticondensing Valve 130 F 1" NPT
Frequently Asked Questions
What is Caleffi F29633?
Caleffi F29633 is a replacement thermostatic cartridge rated 115 F for Caleffi Series 280 ThermoProtec anticondensing valves and Series 281 ThermoBloc units. It is a service part, not a complete valve, and installs into a body already in the piping.
Which valves does Caleffi F29633 fit?
It fits Caleffi Series 280 ThermoProtec anticondensing valves and Series 281 ThermoBloc units, in both NPT and sweat connection styles across the 1 inch and 1-1/4 inch sizes.
Can Caleffi F29633 change my valve's set point?
Yes. Fitting this cartridge sets the valve to 115 F. Cartridges are available at 115, 130, 140 and 160 F, so an installed valve can be re-rated for a different boiler requirement.
What is the warranty on Caleffi F29633?
Caleffi covers this product under its standard two-year limited warranty against defects in material and workmanship from the date of shipment. ZOT Supply is an authorized Caleffi distributor.
- Application:
- Biomass
- Product Type:
- Replacement Thermostatic Cartridge
- Compatibility:
- Caleffi Series 280 ThermoProtec and Series 281 ThermoBloc
- Set Point Temperature:
- 115 F