That sure looks both a mess and a hazard, but it needen't have been like that. These pics show that you can fit an amazing amount of equipment into a small space, make it easy to service yet still create a nice neat job - with a lot of planning
The fir-ply backing board shown here is just 8' x 4'
The system is fed with hot water from a separate boiler room, fired by oil.
[click to enlarge pics]
The whole board: including main 20A isolator, 3 variable output 100W circulation pumps, 3 motorized valves, 2 mechanical mixer-valves [85deg C to 40 deg C for underfloor heating, blue caps ], 2 x duplex breaker panels, 2 main wiring boxes, a digital programmer, 2 wireless programmer receivers, a top-up valve and water gage to maintain the system at 20 psi, 3 x 12v halogen luminaire transformers, domestic hot and cold water pipes and isolator jacks, basin and shower gravity drain, feeds to heated floor hydronic manifolds. All copper pipework 7/8", flow and return, is soldered or compression jointed, with every maintainable component isolatable by 3/4" ball valves for servicing - plus a work light and a recep. The cupboard [it's under the staircase] also contains a 2kW x 150 liter horizontal electric domestic water heater [out of view], the ironing board, all our best china in a cabinet, the fridge, [which backs in from the kitchen] - and our vacuum cleaner!
Close up of programmers. The upper digital unit time controls 85deg C water to a conventional radiator circuit, [ with stats on each rad], feeding 3 beds, a lounge, a [redundant] kitchen and a bathroom. The 2 white receivers control two underfloor heating zones at 40deg C. serving about 2000 sq ft on two floors, lounge, kitchen, a utility room, 1 x downstairs khazi. 2 beds, 2 bathrooms upstairs. Their programmers are freestanding room models, controlling times and temperatures as required. The breaker unit at right contains the EDF relay which switches the water heater on only during low tariff periods - I can overide it if needed.
Part view of pipework, sub-junction boxes etc. and the main manifolds to the floor heating. This system has been running now for about 2 years, the dust is from finish sanding of woodwork and sheetrock in adjacent rooms. As you can see from pic 1, I still have to finish the oak wainscotting and frame out the door. I've been remodelling this house for years - so no rush!
The green verdigris on some of the pipes is from the special flux I used to solder the pipework with lead-free stuff - I obviously didn't wash it all off properly!