Wiring help

[panzerattack]

I’d be very grateful if someone could take a look at the attached wiring diagram I have drawn up and let me know... if it will work.

I’m not sure what to do with terminal 3 on the boiler. And if I wanted to remove the HW/CH programmer all together and just use the programmable thermostats would I just have to connect the ‘A’ terminal on the stats to connector ‘1’ on the terminal block?

Thanks for your help.

View media item 15613

 

[electronicsuk]

No, it wont work, as the switched output from your pipe stat is, apparently, linked to terminals 5 and 7. This will mean that the downstairs and upstairs stats and valves are linked, thus will not operate independently.

Your terminal numbers on the diagram don't mean a lot without having data on the stats, but presumably the idea is that the frost stat will come on when cold, and the pipe stat will break the circuit when the pipe gets hot? Can you not just rely on the boiler to switch off when the water is up to temp, or are you trying to keep the pipes just above freezing point while not having the boiler run too much in the process?

 

[Boilerman2]

Frost stat should go to terminal 7 ONLY, otherwise looks ok to me

 

[twgas]

If you have a by-pass could you not wire the frost stat to term 10. I'm not sure if the boiler's MIs would allow it.

 

[picasso]

you dont have to do anything with terminal 3 on the boiler, if you want to get rid of the hw/ch programmer connect the wires in terminal 4 of wiring centre to terminal 1 of wiring centre

 

[DP]

Take away all wires between ST9400 and strip connector
Terminal A both progstats go to terminal 1 strip connector
Grey wire from motorised valves goes to boiler terminal 3

 

[Norcon]

Take away all wires between ST9400 and strip connector
Terminal A both progstats go to terminal 1 strip connector
Grey wire from motorised valves goes to boiler terminal 3

If you want to bring the heating on using this method outside of the programming times set in the CM 907 , how is it acheived?

 

[DP]

By use of push button right of display

 

[Norcon]

By use of push button right of display

How does this work?
Presumably I press this button ONCE and the heating comes on, right?

If I wanted my upstairs heating ON then I would have to trundle off to an inconveniant location to press this button. Right?

 

[matt1e]

Ideally the connections in grey on your zone valves should connect to terminal 3 on boiler (the factory link between 3 and 4 on boiler should be removed)

the ST9400 should be disconnected

terminal 1 on frost stat should also go to terminal 3 on boiler
and the common on the pipe stat should go to terminal 4 on boiler but this is dependent on what you are providing frost protection for??
if it is just for the boiler then it doesnt need it as the ecotec already has frost protection built in
matt

edited due to balls up I made earlier and pointed out by DP

 

[DP]

Matt, there are two zones. If both stats were connected to 3 and 4 on the boiler, how do you direct the water to upstairs zone instead of dowstairs when upstairs stat calls?

 

[matt1e]

looks ok to me!! DP
thanks for pointing that out, its ok now honest,(I think)
I really shouldn't give advice at half three in the morning I better go check my other posts
matt

 

[DP]

You know what they say- it is human to err

 

[Norcon]

I would ditch the CM907 and fit non programmable room stats and fit a three channel programmer. The HW is obviously not used .

DP has not confirmed it but Im pretty sure the CM907 will operate similar to a Drayton digistat (which I have in my home) where to keep the heating off, the target temperature has to be kept low.
Then to over ride the stat to bring heating on ( outside of programmed times)it has to be flicked up several times. In other words No conveniant boost function. (Its decommissioned now btw and a normal 2 channel programmer used))
Add to this the cm907's will probably be located in remote locations (unless the remote sensor is used) it adds up to an inconveniant set up IMO.
But its your choice panzerattack.

 

[DP]

Programmable roomstat does not have a boost button. Such a roomstat is programmed to give you levels of heat that you need at different times of the day. For instance, if the roomstat is fitted in a hall, design temperature there being 18, roomstat would be programmed to give say 20 for you getting out of bed, to drop to 18 ag you rush about getting ready to leave for work, drop to say 12 as you are leaving house for the thermostat to go into frost protection mode.

One return to your house, ther roomstat temperature is programmed to 17 or 18 to rise to 20 when you become inactive reading a book or watching TV. Programmer drops to 12 once you are asleep.

Overide is actioned by bring the temperature to 18 or 20, depending on you being active or 'at rest'. Such operation gives better control than 'single' setting' dial thermostat that has to be constanly tweeked.

Hope above helps. I would keep the progstats. Have not checked above for mistakes as am rushed to go out