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No Heat on First Floor - Help!

Unknown
Unknown
in THE MAIN WALL
If it is a standard generic relay you might try Mc Master Carr.

http://www.mcmaster.com/

They can usually get an order to you by the next day.

Comments

  • Eric Tardif
    Eric Tardif Member Posts: 38
    TACO SR502 may need replacement?

    Hi Everyone,

    I've had 3 different boilers in three years installed in my house but the current one is the most efficient: Lochinvar Knight KBN105 boiler. It heats 3 gallons of water flowing through a radiator (Heat Controller). Air is blown through the radiator throughout the first floor (zone 1). The second floor has its own heat controller (zone 2). No domestic hot water is heated by the boiler.

    The TACO SR502 2 Zone switch is wired to each thermostat on each floor. Zone 2 works fine.

    The installer fried the zone 1 relay and replaced it with a new one. We've been having problems with zone 1 ever since. I think the SR502 circuit board should be replaced. When I short the wires to zone 1 thermostat to put a call for first floor heat, the fan to the heat controller starts blowing cold air through the vents. The zone 1 LED on the SR502 board never lights. There are cases when the LED light does go on but I'm not sure why.

    Thanks for any assistance!
    Eric - Just South of Boston
  • Eric Tardif
    Eric Tardif Member Posts: 38
    Found Problem!

    It looks like the wiring from the first floor thermostat to the TACO SR502 is broken because when I short zone 1 input at the SR502 the boiler works! (It's funny that it didn't work before when I shorted it.) The thermostat is fine since I replaced it with a brand new one and it's the same as the second floor thermostat.

    I think this will do initially and then something else will come up as a problem because I remember shorting the input before with no result.

    A little detective work is in order here. ;)
  • Eric Tardif
    Eric Tardif Member Posts: 38
    Relay Problem

    I traced the wiring from the thermostat to the TACO SR502 and it goes through the heating controller! So I opened it up and located an old relay from the installer who had used it to temporarily get the heat started. I'm replacing it with a double pole relay rated at the same amps for a 24 Vac coil. Now I have to find a place south of Boston who supplies these relays. Any suggestions?

    Eric
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