Pros, Join Our TradeMaster Program!
The Switching Relay 301P connects to one thermostat and operates a circulator and boiler to provide heating to a hydronic heating system. The 301P includes optional exercising to prevent circulator seizure when not in use, and optional post purge operation maximize energy savings.

  • 20 VA transformer
  • 3-year warranty
  • CSA approved
  • Compatible with all low voltage thermostats
  • Fuse protects pump
  • Hinged cover
  • LED for power and zone
  • Post purge
  • Pump exercising
  • Spare fuse included
  • Thermal circuit breaker protects transformer
  • Top, bottom and back conduit knockouts

  • Control: Microprocessor control. This is not a safety (limit) control.
  • Packaged weight: 2.5 lb. (1125 g)
  • Dimensions: 6-11/16" H x 4-15/16" W x 2-7/16" D (169 x 123 x 62 mm)
  • Enclosure: Cover: ABS plastic, Base: galvanized steel, NEMA type 1
  • Approvals: CSA C US
  • Ambient conditions: Indoor use only, 32 to 122°F (0 to 50°C), RH<90% non-condensing
  • Power supply: 115 V (ac) +-10%, 60 Hz, 5 A
  • Transformer: 24 V (ac), 20 VA
  • Control load: 7.5 VA
  • Fuse: T5A 250 V slow blow, spare fuse included
  • Pump relay: 230 V (ac), 5 A, 1/3 hp
  • Boiler XX end switch: 24 V (ac), 5 A
  • Warranty: Limited 3 Year Warranty
Hide Description
Manuals (2)
Product Type:




Power Supply:



3 Years

Speak with a real person who will go out of their way to help!
Closed Now: Phone Hours
Monday – Thursday
8am–7:45pm ET
9am–7:45pm ET

1 Product Reviews

Product Q&A

Add-on Item

This item is cost-prohibitive to ship on its own but is available to ship with orders over $200.

Why don't we show the price of this item?

We try to always offer you the lowest prices possible, but some manufacturers require that we only show these low prices once you take further action.

To see the price, simply add the item to your cart or sign in.