Radiators not heating up properly – communal heating (not gas)

Radiators not heating up properly – communal heating (not gas) – Beckenham, BR3 – urgent. We're looking for a qualified heating engineer to inspect and fix the heating in a rental flat in Beckenham. Please note: this is NOT a gas boiler. The flat is on a communal heating system, with no gas supply to the flat. The heating comes from the building's shared system through a heating unit in the flat. The radiators aren't heating up properly, although the hot water is working fine. The radiators feel the same temperature at the top and bottom. The heating unit shows the heating set to 45°C and the hot water to 65°C. The tenant has been without proper heating for a while, so we'd like this sorted as soon as possible. The tenant is available 9:30am to 2:20pm. In your quote, please include: your call-out and hourly rate, what's included, and your earliest availability. Please also confirm whether you have experience with communal heating systems, whether you accept card payment, and what warranty you give on repairs.