Preventative maintenance on a Weil McLain aqua-balance combi style high efficiency boiler. Cleaned out heat exchanger, installed new firewall insulated disc, replaced flame sensor/igniter and also replaced gaskets for various components per manufacturer instruction. Cleaned trap, tested condensate pump. Heating limit set to 190. Domestic water set to 125. Verified proper water pressure. Combustion analysis CO 8 PPM. Verified all (4) zones are working. System operating properly upon completion of maintenance service. ***Note-some “banging” noises will occur due to finned tube baseboard copper expansion and contraction.*** Weil McLain M#AB-120-C, S#1913L60027, CP7509520. ***Annual maintenance kit-S AB Annual Maintenance 80-120 P/N-640000114. Collected quoted price for PM HT w/annual maintenance kit.