Responded to no-heat call for aging boiler system showing Low Water Pressure error. Utilized transfer pump to replenish water in the closed hydronic heating system, which services in-floor heating on lower level and portions of upper floor. During diagnostics, identified water leakage from manifold zone actuator requiring replacement, along with evidence of water damage to additional components. Recommended replacement of upstairs manifold pump flange and faulty pressure gauge. Restored system pressure to operational levels and provided repair estimates.