Is this correct OR just totally bad practice.??

[westfire32]

I have already made several postings on this forum regarding my daughters heating system running off 2 Combi boilers in parallel.
Unfortunately the more that I see of this system, the more I am convinced that the experts who "adapted/converted" the 2 systems into 1, were related to wyatt earp. I had occasion to take up some floor boards to trace some pipe runs, and could hardly believe the quality of workmanship, and the the lack of any thought. I am sure that if I were to replumb the system completely, I could make a profit on the piping removed.
However, my questions.
The boilers feed onto a common flow/return loop, which then splits to provide the heating system on one flow/return loop, and also to 2 megaflow CL250 tanks on another flow/return loop.

The hot water loop has a motorised valve fitted, and controlled by a thermosat built into one of the tanks. this MV is fitted at the boiler end of the loop. Would it be better fitted at the Tank end. (see questions below before answering)
I believe that it is normal to have one radiator on a system without any thermostatic control, to provide an uninterrupted return path. On this system it is the bathroom radiator, HOWEVER this radiator is on the Tank flow/return loop, and AFTER the MV. Is this correct/good practice/bad practice/ totally incorrect.
In addition, there is another radiator that has been added with the flow on the heating loop, and the return on the tank loop. Is this correct/good practice/bad/practice/ totally incorrect.

Your comments and assistance would be greatly appreciated.

 

[bengasman]

2 combis in parallel AND 2 cylinders, tanks are something totally different, in one house? Whoever designed this must be totally of his rocker. Unless of course, this is a 30 bedroom country mansion with 10 bathrooms. No wonder there is a lot of pipework. If I were a gambling man, I would put a fair amount of money on it that this was thought up by one of those builders who thinks he knows it all. Second bet would be that there are more than a few points that do not comply with building regs. Third bet would be that electrical installation would have at least one code1. Fourth bet would be that I win ALL 3 bets.

 

[Paul Barker]

The cylinders should be closest return to boiler, no rads should return via cylinder return. bathroom rad should be changed onto heating side and an autobypass fitted if the boilers don't include an autobypass stated in manufacturers instructions that no other bypass is required.

Time and temperature control of heating and hot water with boiler controlled by both.

 

[westfire32]

bengasman you may recall my earlier postings regarding this "installation"

was two houses converted into one, by previous owners. Everything on the surface looks great.. best of everything, bisque radiators costing £750 + each (undersized though), but once you start to look under the facade. total rubbish, no one took the time to just look at the most efficient way to hook these systems together (or did they need to be).
I would still like to split the system up to be much more efficient, but every time I thing of a way to do it, the pipework won't allow me to without major work.

Further question. Can you think of any way to shut off one megaflow, and perhaps use it 2 or 3 times a year, without creating a stale water health hazard in it. the mechanics of doing this would be no problem, its just how to get around "stale water". could it be easily drained/refilled???

By the way nengasman. I do have an occasional bet.. but not this time..