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Blake

Plumbers Arms member
Plumber
Gas Engineer
Jun 1, 2008
1,063
190
63
Nottingham
Evening peeps,

Just wondered if anyone can shed some light on a programmer swap I have done.

Previously had a Danfoss Randall 102 programmer which would allow water only or heating and water.

House is a horror show and all the wiring is a DIY job by previous owner.

Got a free Honeywell ST9400 so thought I would change it. System is fully pumped with a 2 port valve only, no room stat or cylinder stat.

Basically, HW when selected works fine and boiler and pump run. Select ch only and nothing happens, unless the HW button is pressed also.

Is there any way with this programmer that I can put a link in so that when CH is selected HW comes on also and fires up the boiler?

There is no wiring centre, and at the moment I have the live to the 2 port wired to CH on and the pump and live feed to boiler wired into HW on. So basically all that is happening when CH is selected is the 2 port is opening.

I have no wires in CH off or HW off ( I dont even know what these are for 😕)

I think that's everything although my head is a little mashed 🙂 Oh, and you will be pleased to know I am booked on the honeywell course in a couple of months time 😛
 
Same yorself a whole load of grief , buy a second zone valve , a room stat and cylinder stat and do it properly. The wiring will then make a lot more sense
 
I'm just gonna stick the old one back on 🙂 I think its a honeywell 2 port, but it's under the floor in the bathroom along with the pump and I don't feel like ripping the floor up at the moment!
 

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