I've been helping a colleague with some stuff in his house. It's taken me a while to get my head around the wiring for the heating - at first I had 5 ends of 3-core&E cable until I found the last JB hiding where the original boiler was.
First question. It's been wired without a connection from the HW-Off terminal on the time clock to the grey wire on the valve head. As I understand it, this means that if the time clock allows CH without HW, then the valve will always run to the central position when the CH is on. But because the orange wire won't go live, then the boiler and pump won't come on.
So CH won't work without HW also on at the time clock.
Have I got that correct ?
Next step having figured out how it's wired, is to figure out what is and isn't working. Not sure the room stat (or perhaps CH output on programmer is working either
The system also has a pair of stats in the garage (where the boiler is fitted). A frost stat and a pipe stat. The two are in series, so I figure the frost stat will turn on the boiler when the air temperature is low, and the pipe stat will disable this when the pipe is warm (it's set at about 30˚.
Is it normal to connect this so that it just turns on the boiler and pump regardless of HW and CH settings (as it is now), or so it overrides the CH clock and stat to bring the heating on, or something else ? I guess just turning on the pump and boiler will protect the vulnerable pipework - the house itself can be protected by leaving the heating on with the room stat turned down low.
Lastly, I imagine this isn't uncommon, did the tiler think electricians are also gynaecologists and that's why he left such a small hole to work through ? For good measure, if you look closely you'll see an unconnected and unsleeved earth wire floating about in the back of the box.
First question. It's been wired without a connection from the HW-Off terminal on the time clock to the grey wire on the valve head. As I understand it, this means that if the time clock allows CH without HW, then the valve will always run to the central position when the CH is on. But because the orange wire won't go live, then the boiler and pump won't come on.
So CH won't work without HW also on at the time clock.
Have I got that correct ?
Next step having figured out how it's wired, is to figure out what is and isn't working. Not sure the room stat (or perhaps CH output on programmer is working either
The system also has a pair of stats in the garage (where the boiler is fitted). A frost stat and a pipe stat. The two are in series, so I figure the frost stat will turn on the boiler when the air temperature is low, and the pipe stat will disable this when the pipe is warm (it's set at about 30˚
.Is it normal to connect this so that it just turns on the boiler and pump regardless of HW and CH settings (as it is now), or so it overrides the CH clock and stat to bring the heating on, or something else ? I guess just turning on the pump and boiler will protect the vulnerable pipework - the house itself can be protected by leaving the heating on with the room stat turned down low.
Lastly, I imagine this isn't uncommon, did the tiler think electricians are also gynaecologists and that's why he left such a small hole to work through ? For good measure, if you look closely you'll see an unconnected and unsleeved earth wire floating about in the back of the box.
