is my thermostat control relay bad? (water boiler)?

I am talking about the type that screws into piping and senses water temp. right outside of boiler in supply piping. My radiator system only gets hot in half the house when I turn (house) thermostat up. My boiler kicks on but only heats up a few radiators.Pump does not seem to kick on. When I bypass relay swith and wire direct to circ. pump, it runs and heats up all radiators.Pump then runs constantly but does heat up house. If I adjust house thermastat the system will heat accordingly but with pump running constantly. When I take off the back my relay swith only has one control which is set at 180. why doesn't my pump run when it is wired correctly

2 Answers

  • Max J
    Lv 5
    1 decade ago
    Best Answer

    it does sound like either a bad or stuck relay. One thing that not a lot of contractors do, but I've had good luck with is a Johnson Controls 9010-T temperature controller, but they are expensive. Relays themselves are actually pretty inexpensive, and it sounds like you do know about them to some extent, so replacing it wouldn't be a bad idea. Relays typically are designed for 5-10K cycles, and will go bad eventually. other than the electrical usage, the pump running constantly shouldn't hurt anything as long as your boiler level and return flow is sufficient to not cavitate the pump. If your system has high load, the pump will need to run continuously to keep the boiler at level to prevent damage and scale. I know it's kind of vague, but I hope it helps some. Without knowing system specifics it's hard to nail the cause of the problem with a boiler system.

  • 3 years ago

    there's no experience in having the warmth as intense in the process the day while no one is residing house as while everybody is residing house at nighttime, ur thermostat will enable u set it as much as decrease and better on a timer, my father does this at our residing house and he very own an HVAC busines the place i artwork and this is what i propose all our consumers to do it relatively is fee useful

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