Commercial heating - baffled by this one

[Marty92]

Hi all,

I am contracted to replace a control system for a commercial heating system, it's packed up following the removal of two older boilers, replaced by one w200.

The boiler swap was all very dodgy - I given up asking questions!

I am some what confused by the original intended design.

There are 7 zones which are a mixture of rads and UFH.

4 of said zones have satchwell csc's and Svt's

The csc's control satchwell arx1202's / mbx4451 valve bodies

The valves are positioned in the returns just prior to the return header, the centre port is connected from the flow header via a bypass valve in the direction of standard flow.

Essentially they are connected as diverting valves.

given that I have OS temps and the system seems to be designed for weather compensation how can this work?

I cannot see any means of limiting flow water temperature or any way of differentiating temperatures between zones.

What am I missing?

thanks

martyn

 

[Ermintrude]

That on return back to headder? I wouldn't think so

 

[Marty92]

That on return back to headder? I wouldn't think so

Afraid not, that's in the line from the flow header to the centre port (arrow pointing up toward the valve from the flow)

 

[Ermintrude]

Not sure , could the bafoon have mixed up flow and return and swapped few bits around. Could pumps be flipped at flanges and csc rotated to make it work? Valves look a ballache to change out?

 

[Marty92]

I'm going to give it another look Thursday afternoon, altering any pipework will be a severe headache!

 

[Ermintrude]

Get a schematic

 

[Dotty]

Your 3 ports are in the wrong place. Should be mixing flow and return to give you modulated temps.

UFH off that set up worries me.

Sit down, spend a few hours and sketch the bugger out zone by zone.

 

[Marty92]

That was my thoughts too croppie, it's been running since 1989 though....

Its just possible that they are not mixing valves, they could be flow regulating valves, the point if them- I'm not sure but slower flow longer residence.

I'm not too concerned about high temperature to the floor as heat loss is massive before it even gets there! Not great but it is what it is!

I will be drawing for the O&M in anycase...

 

[wetdrip]

Love a thread that the big boys can get their teeth into.
Got you all thinking, great stuff.

 

[newcastle phill]

Love a thread that the big boys can get their teeth into.
Got you all thinking, great stuff.

Ayeeee not better than them 'big' boys complete with heavily elasticated waist band trousers getting their teeth into stuff lol

 

[wetdrip]

Ayeeee not better than them 'big' boys complete with heavily elasticated waist band trousers getting their teeth into stuff lol

When episode 2 coming along...can hardly wait.
Where are you Marty92?