What system do I have?

[Zilla]

Sorry I am just trying to understand the type of system I have installed at home, and if it can be improved in anyway before I can afford to have it upgraded/replaced fully.

I currently have an Ideal Concord W - WCF 255 A

It has an old Programmer that has the option to program 2 on and off times for CH and HW, but not different times for each day.

There are no room stats at all, and as far as I can see, no cylinder stat.

I also have a pump on the CH but again as far as I can see, no valves that are powered.

Any advice would be welcome. I am currently saving for a new boiler, but the prices were a lot more than first expected although I did call at the start of winter when everyone seemed flat out.

 

[ianmcd]

can you get CH without HW ? or does the HW come on when you select CH on its own ?

 

[45yearsagasman]

Disregard the gas supply pipe. If you have 4 pipes coming from your boiler and the pump is underneath the boiler, which was commonly done with that model, you probably have an old gravity hot water and pumped heating setup.

 

[Zilla]

HW can be turned on or off without the CH coming on. If I turn CH on the HW light also comes on. (When I first moved in some years ago, it was the opposite way around, I called a guy in to service the boiler and he fixed the issue with a switch behind the programmer [pumped/gravity its down now not sure what the word it is switched to is, I can check] and moved some of the wires behind the programmer.)

The wires behind the programmer are in the image attached.

 

[shambolic]

Gravity hot water pumped central heating.

 

[Zilla]

OK, so this is probably overkill but it would get me some brownie points. The other half got me a Nest for Christmas! I had been looking at them and I dont think she realised what might be required to fit it.

Can the Nest 3G actually work this system. If so what would connect to what outlet from the Nest? Would it replace the old programmer, or do I need a 10 way connector block to hook things up?

 

[ianmcd]

as already advised you have a gravity HW pumped CH system but your wiring diagram that you put up is wrong, the boiler live comes from the HW on terminal and the pump live comes from the CH on terminal and that is why you cant get CH on its own the HW terminal brings the boiler on and the HW is heated by gravity , when the CH is switched on then the pump comes on and pumps the water around the radiators .

 

[Zilla]

checked and the programmer is as you said! I have updated the image.

What if any thing can be done to make this system better whilst waiting for the money to replace/upgrade to a newer boiler? I have no thermostats at all at the moment and keep thinking this isnt ideal as the boiler will keep running until its internal stat is hot enough.

 

[ianmcd]

The nest could possibly be fooled to operate on your system but you wouldnt have individual control of your HW, it would take a bit of know how to override the HW control it could be done but you will need an experienced installer its not really a DIY install.

 

[Zilla]

can I leave the existing programmer in place for the HW, and use the Nest for the CH? I thought I saw a diagram showing the existing programmer in place set to always on, with the nest in line to take over the on and off of the heating side?

 

[45yearsagasman]

The way your system is configured the boiler has to fire for CH (obviously) and it will also heat the cylinder as well. You cannot stop that without adding zone valves to your system, say Y Plan, rewiring, and making it fully pumped.

 

[Zilla]

can I use the Nest though to:
a) time the HW as I currently do with the old programmer, just with no thermostat to turn it off.
b) provide power to the pump and the boiler when I want heating?

If so which of the nest outlets do I need to use, and to what do they connect?

Thanks

 

[ianmcd]

you are trying to control a log burner with an Iphone 6 , cut your losses and get a new boiler properly installed, there is a way that you could fool the nest but that completely goes against the whole point of installing one, they are learning thermostats and gather information about how you use your energy and they compensate that, its like asking your great grandad to set up your sons Ipad

 

[ianmcd]

Or thinking about it again its probably more like asking a ten year old to light a coal fire

 

[Zilla]

I'm forgetting the nest, far too complicated!

But so I understand what's what, when my programmer selects HW on the boiler fires via terminal 3. But when it selects CH the pump is turned on via terminal 4 but it also internally bridges terminal 3 and 4 together to also fire the boiler?