Out of my depth please help!!!

[lambchop]

3 rd time ive tried to post this... so this is the really really short version

Is there a 3 port valve that only has 3 wires (l,n,e) on it made by honeywell please guys that has a relay in the wiring centre?

 

[Roger Welton]

Yes diverter valve (hot water priority) look up W plan

 

[lambchop]

Thanks Roger for quick reply, custard says the hw is too hot which i thought the valve is not closing properly, also the pump is permanantly live the other port of the valve is connected to the return of the boiler which cuts out due to overheating.

 

[Roger Welton]

Sounds strange no heating from the boiler?

 

[lambchop]

Boiler producing heat, ch pump always live, hw pump always live. 3 port valve to hw i dont think closes properly if hw side is closed becos pump is always on the primary flow is diverted straight back into the return so boiler keeps overheating and cutting out. There is a gate vale to restrict the return back to the boiler. Custard has messed about with everything down there. I am reluctant to turn turn this gate valve as in the MI's there can be a bypass fitted. Also if it is turned down to low the HTG primary will be diverted back up the cylinder return coil! hope this makes sense...

 

[AWheating]

Typical W plan FYI

 

[lambchop]

Thanks very much but I must be having a brain fart as this system has 2 pumps, 1 for htg & 1 for hw and the 3 port valve is left of the header and on the primary for the hw. 1 port goes to the the cylinder and the other port is on the return back to the boiler. The pump for the htg is right of the header. Both pumps are live no matter if room or cylinder stat are calling or not. If hw is statisfied the return back to the boiler is scalding hot as the pump for the hw is always on and the circuit from the primary flow back to the return to the boiler is about 1.2 metres of pipework

 

[Roger Welton]

I gues the diverter on the Hw was to allow for a pump overrun, sounds like a interesting one, just need to work through it with a multimeter to see what's going on (or replace with something sensible)

 

[lambchop]

Hi lads thanks for all the help. I think the system Im cack handedly describing above is a SMC Controller twin pump system (has got a relay) with a 3 port valve on the hw primary acting as a pump overrun!... a Y plan system is the way to go

 

[Barry98]

get some pics fella , give us a butchers

 

[lambchop]

will do lads