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FB-7 Relay? how to wire it. Its between ofhwh&boiler

I have an Oil fired hot water heaterand Oil fired boiler. The single oil line is teed at the boiler. Its been 15 years since I worked on Oil burners, but remembered that this relay attached to the Hot water heater & was wired between that and the boiler to prevent both from trying to start at the same time thus locking the burners out. I have a relay the supply house sold me, but no one there knew how it was wired. Any help ? Thanks.

Comments

  • Big Ed
    Big Ed Member Posts: 1,117
    Relay

    Best to change the oiline but...

    Need to check the relays diagram , but the basic set up is...

    The orange wire line voltage after the hwh primary relay powers the preference relay. Normaly closed contacts on preference relay is conected to TTor line before the before the boilers primary relay. All safeys and limits need to be checked after install........
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