| Application: | Heat Only |
|---|---|
| Mount: | Horizontal |
| Options: | Works with Sensor |
| Control Panel: | Digital |
| Programmability: | Non-Programmable |
| Control: | Microprocessor Control |
| User Interface: | Push Button |
| Accuracy: | 0.2°F |
| Operating Temp Range: | 41°to 99°F 0.5°F increments |
| Environment Range: | 32°-122°F |
| Power Supply: | 24V +/- 10% 60 Hz 15 W Max |
| Output: | TRIAC output 24 VAC, 15 W Max |
| Floor Limiting Range: | 50°-104°F |
| Type: | Thermostat |

No there is not, most thermostat companies do not make remote sensors that are designed for use in water
There are no major differences other than that the 501 is a 4-wire unit.
The idea behind radiant floor heating is to have a consistent floor temperature. Most installers do not use a setback style thermostat because you never really change the settings on the thermostat for radiant heat.