Wondering if someone can answer my queries. We have a firebird C35, downsized to 26kw condensing boiler. 2 Ufh manifolds and rads. When the boiler runs the rads and manifold 50m from boiler the boiler runs perfectly. When the boiler runs the closest manifold 15 m away from boiler heating approx 150sqm floor area, boiler never gets up to temperature, a new pump was fitted running on constant pressure outside of boiler. Pump runs extremely fast on closest manifold, but boiler never gets past 50 degrees. When other manifold and rads are also run with this manifold system runs poorly. Anyone have some ideas for me please.