Strange Setup With Fault

[kme]

So - its (sort of) like a gravity / pumped system...............except it isn`t.

Oil fired boiler with external pump in primary cct; feeding up to a "Dunsley/Baker neutraliser" (don`t ask - but ALL the pipework seems to go in / out of it!) 

http://www.dunsleyheat.co.uk/LINKUP_LEAFLET.pdf

Its got a clamp-on stat on the side of it - haven`t yet removed clamp to have a look.

We`ve a standard indirect cylinder, with tank stat.......BUT there is also an in-line 2 port valve, which is a "normally open" configuration ( i.e. shuts when power applied. The switch contacts of this valve are not used.

Then we`ve the heating side, which has a room stat and a second circ. pump, in the CH return. At the moment, its been wired so that the "satisfied" line from the neutraliser stat goes to the "call" from the CH stat (which is also "pump run"). 

The fault is that the rads get hot, irrespective of the setting of the room stat.

I think that this neutraliser / normally open valve, are putting me off - I haven`t got my bonce around this yet ( only saw it this afternoon).

Anyone seen anything like it before???

 

[kme]

Looking at my notes; I`m wondering if they`ve  a wood burner feeding into it, too - I thought the idea of those thingies was to counter effects of one heating source on another; supplying the same stuff. But I could be mistaken.

 

[Doc Hudson]

 My son used to do them

Well if your son used to do them, give your son KME's number and he can talk him though it.

Doc H.

 

[Technician]

Dunsley Heat;  Used to visit them.  They made a steel fabricated hearth

for a coal fire which put the boiler adjacent to the heat source with only

steel plate 0.5" thick between them.  Used to watch them being hydrostatically

tested.

 

[SLIPSHOD & SLAPDASH]

A couple of years ago i moved a programmer and had 3 return visits to get it working correctly. No one including the plumber, homeowner or builder told me they also had a wood burner connected into the system along with the gas boiler  X(

 

[kme]

Think I`ve got the wiring straight in my head now. Need to verify I`ve got all the logic options correct - then I`ll (try) to draw it out, for anyone`s future reference.

 

[steptoe]

Albert can you explain this in simple terms please for KME

NO,  :|

but it sounds to me like the old heat bleed system they used to have with the bathroom radiator on all the time,

unless the system called for heat then the pump kicked in and fed ther rest of the system.

 

[kme]

That`s what it is.

When I first looked at; it didn`t twig why the neutraliser was there - afterwards I realised the reason for the "always open" HW valve, was because of an uncontrolled heat source (eg wood burner).

After realising  WHY things were as they were, I could rationalise how they ought to be; and from there to why it wasn`t working correctly.