Oil burner starts & runs when not required

Old 10-26-12, 09:41 AM
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Oil burner starts & runs when not required

I have an oil burner for hot water baseboard heat + supplies hot water to faucets.

It occasionally starts and moves hot water through heating pipes when the temperature settings on each of the 3 zone thermostats are set lower than the current temperature.

While I'm unlikely to attempt D-I-Y repair, I would like to know the possible causes.

Thanks in Advance!
Old 10-26-12, 11:44 AM
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If it just starts by itself it could be a thermostat. You'll need to determine which zone is calling for heat so you know where to start looking.
Old 10-26-12, 12:45 PM
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Because your boiler has a tankless coil to supply domestic hot water it needs to maintain a certain minimum temperature inside the boiler at all times. If it is also running the circulator pump then you have a control problem. It is most likely the setting of the minimum temperature circulator control although if it only happens on an intermittent basis it could be a sign of imminent control failure.

Posting several pictures of the controls on your boiler might help us to pinpoint the exact cause.
Old 10-26-12, 01:01 PM
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Just a note it could be one of the flow controls also. ( Only if you have circs and not zone valves.)

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