{"product_id":"weil-mclain-591-391-824","title":"Weil McLain 591-391-824 Wiring Harness","description":"\u003cp\u003eThe \u003cstrong\u003eWeil McLain 591-391-824 Dual Circulator Wiring Harness\u003c\/strong\u003e connects the \u003cstrong\u003econtrol module\u003c\/strong\u003e to the \u003cstrong\u003esystem circulator\u003c\/strong\u003e and the \u003cstrong\u003eby-pass circulator\u003c\/strong\u003e on the \u003cstrong\u003eWeil-McLain GV Series 3\u003c\/strong\u003e gas boiler. The \u003cstrong\u003eGV Series 3\u003c\/strong\u003e parts list shows it twice: in the \u003cstrong\u003eignition controls\u003c\/strong\u003e group (Fig. 7) as \"Wiring Harness, Control Module to System and By-Pass Circulators,\" and again in the \u003cstrong\u003etrim group\u003c\/strong\u003e (Fig. 8) as \"Wiring Harness, Dual Circulators to Control Module.\" The photo shows a black jacketed cable with \u003cstrong\u003etwo strain-relief fittings\u003c\/strong\u003e at the circulator ends, \u003cstrong\u003egreen and white conductors\u003c\/strong\u003e, and a \u003cstrong\u003ewhite plug connector\u003c\/strong\u003e for the \u003cstrong\u003econtrol module\u003c\/strong\u003e end.\u003c\/p\u003e\n\n\u003cp\u003eA \u003cstrong\u003edual circulator\u003c\/strong\u003e harness matters because the \u003cstrong\u003eGV Series 3\u003c\/strong\u003e \u003cstrong\u003econtrol module\u003c\/strong\u003e runs two pumps: the \u003cstrong\u003esystem circulator\u003c\/strong\u003e that moves water through the heating loop and the \u003cstrong\u003eby-pass circulator\u003c\/strong\u003e that works with the boiler loop. Both pumps are powered from the \u003cstrong\u003econtrol module\u003c\/strong\u003e, and this single harness carries that power. When one pump does not run, or both quit together, the harness is a common culprit, especially at the \u003cstrong\u003estrain-relief fittings\u003c\/strong\u003e where the jacket is squeezed and at the plug where terminals can back out.\u003c\/p\u003e\n\n\u003cp\u003eTo check it, shut off power and look at the \u003cstrong\u003estrain-relief fitting\u003c\/strong\u003e at each circulator end for a cracked jacket or exposed conductor, then look at the \u003cstrong\u003ewhite plug\u003c\/strong\u003e for browning or a loose pin. Test each conductor for \u003cstrong\u003econtinuity\u003c\/strong\u003e from the plug to the circulator end before you condemn a pump or the \u003cstrong\u003econtrol module\u003c\/strong\u003e. Order by the number on the harness and match the photo: a black cable with \u003cstrong\u003etwo strain-relief fittings\u003c\/strong\u003e and a single \u003cstrong\u003ewhite plug\u003c\/strong\u003e. Related GV harnesses are the \u003cstrong\u003e591-391-819\u003c\/strong\u003e, which feeds the \u003cstrong\u003eigniter\u003c\/strong\u003e, and the \u003cstrong\u003e591-391-820\u003c\/strong\u003e, the \u003cstrong\u003e9-pin\u003c\/strong\u003e control circuit harness used on the \u003cstrong\u003eGV Series 1 and 2\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eKey Benefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePowers Both Circulators:\u003c\/strong\u003e One cable runs the \u003cstrong\u003esystem circulator\u003c\/strong\u003e and the \u003cstrong\u003eby-pass circulator\u003c\/strong\u003e from the \u003cstrong\u003econtrol module\u003c\/strong\u003e.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eListed for GV Series 3:\u003c\/strong\u003e Shown twice on the \u003cstrong\u003eWeil-McLain\u003c\/strong\u003e \u003cstrong\u003eGV Series 3\u003c\/strong\u003e parts list, in the \u003cstrong\u003eignition controls\u003c\/strong\u003e and trim groups.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eStrain-Relief Fittings Included:\u003c\/strong\u003e The \u003cstrong\u003etwo strain-relief fittings\u003c\/strong\u003e at the circulator ends are already on the cable.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePlug-In Control End:\u003c\/strong\u003e A \u003cstrong\u003ewhite plug connector\u003c\/strong\u003e seats at the \u003cstrong\u003econtrol module\u003c\/strong\u003e, so there is no splicing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCommon Questions\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWhat does the 591-391-824 connect?\u003c\/strong\u003e The \u003cstrong\u003econtrol module\u003c\/strong\u003e to the system and by-pass \u003cstrong\u003ecirculators\u003c\/strong\u003e on the \u003cstrong\u003eGV Series 3\u003c\/strong\u003e boiler, per the \u003cstrong\u003eWeil-McLain\u003c\/strong\u003e parts list.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eIs it for a single circulator?\u003c\/strong\u003e No. The parts list calls it the \u003cstrong\u003edual circulator\u003c\/strong\u003e harness, and the photo shows two circulator-end fittings.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWhat should I check before replacing it?\u003c\/strong\u003e Check the \u003cstrong\u003estrain-relief fittings\u003c\/strong\u003e, the jacket, the \u003cstrong\u003ewhite plug\u003c\/strong\u003e and the \u003cstrong\u003econtinuity\u003c\/strong\u003e of each conductor. If both \u003cstrong\u003ecirculators\u003c\/strong\u003e run when powered directly, the harness is the likely fault.\u003c\/li\u003e\n\u003c\/ul\u003e\n\nDisclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.","brand":"Weil McLain","offers":[{"title":"Default Title","offer_id":68025748357298,"sku":"591-391-824","price":53.63,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1838\/2375\/files\/591-391-824.jpg?v=1794598483","url":"https:\/\/www.gsistore.com\/products\/weil-mclain-591-391-824","provider":"GSIstore","version":"1.0","type":"link"}