No Central heating without turning hot water on

[shan70]

Hi,
I read previous thread which seems similar to my problem but I can't get exact answers.

I moved in a house already 2 years and noticed central heating can only be switched on when hot water is also on. I have Lifestyle LP241 programmer. Hot water can run independently but not central heating. I ignored it for last 2 years but seeing gas bill rocketing I would like investigate. I hope you, all experts can help me.

1) I programmer LP241 is not at default program. I changed HW and CH time independent to each other. Also confirmed the fault by manually switched one or, other leaving the thermostate at 30degC.

2) The jumper link at the back of LP241 is at "P" but I don't know whether my system is fully pumped or gravity-fed. How can I find out what system I have?

3) In the terminals at the back of LP241, port L, N, 3, 4 are connected. 3, 4 connected from a incoming connector both wires are black in color. Port 1, 2 don't have any connection.

 

[cross thread]

looks like its not wired for heating only .from photo you have a y plan sysytem so the wiring can be adapted ,search should show you what you need to alter

 

[Hugh Jaleak]

You've got a 3 port valve, brass T shaped part with white box on the top, 3rd pic, which indicates a fully pumped system. Programmer is also set to 'P' for pumped, so plumbing is there. Need to check out electrical side, if your confident working with mains electricity Google 'Y plan', and compare it to what you have got.

 

[shan70]

I appreciate quick response. I already ticking off box like I have fully pumped system. I tried to look at the web for Y-plan. Am I missing a connection at terminal-1 (HW-OFF) at the back of LP241 (in picture 1)? It seems, I have 5 core wire coming from top of LP241. If there is not another core hidden (and I need to connect HW OFF) then I am in trouble as that cable went to the back of kitchen cabinet. Then the cable run 2-3 meters on top of cabinet before going to the loft.
1) If I switched off the LP241 (I changed it to LP522, left by previous owner), is that switch off the whole heating system?

Or, I should switch off house mains to be in safe side?
2) I just noticed "Lifestyle Heating Control Pack" installation and wiring guide last page shows either 4 core or, 5 core cable to programmer!!
3) I now start thinking whether I should use the GY earth cable to connect the terminal-1 (HW off)

Thanks in advance for the advice.

 

[Johnmdc]

No you cannot use the g/y (earth) wire because if you did none of your system will be earthed.
You will need to run an extra cable as you say from terminal 1 on the clock to the grey wire on the valve, which will already be connected to HW satisfied on the cylinder stat.
Changing the clocks won't make a difference to how the system works but the LP522 will allow you to have different times during the week and at weekend.

 

[ServiceNumpty]

There's a cable missing. Terminal 1

 

[ServiceNumpty]

****** read more - assume less.

 

[Johnmdc]

????

 

[ServiceNumpty]

Not you bud, me. Saw the missing link in terminal 1 but didn't read the last 2 posts.

 

[Hugh Jaleak]

It may not just be a matter of running an extra wire, we do not know how the rest of it is connected. Heating electrics are fiddly, and every connection must be present and correct for it to function correctly and be safe.

Using an earth as a extra core is not allowed and could render the whole house unsafe. If you are unsure, get someone who is qualified to have a look.

 

[Echo the husky]

I would advise calling an electrician anyway, as this is yet another example of terrible central heating wiring it's like one a day now. Just look at the stupid connector blocks used to extend the flex on the valve, the supply from a 13A plug is untidy, and the wiring has been incorrectly installed.

 

[shan70]

I am now thinking running a extra cable may not be too much. I can make 2 holes at the top and bottom of the kitchen wall cabinets. I can keep original one as it is. So, question is what spec single core cable I should buy?

About using the earth wire: The earth is coming from the socket below LP522 which is then connected to one off the 5 core cable. The LP522 case is made of plastic, so it don't serve any purpose for LP522. If I get junction box earth wire from somewhere else then that could make other instruments connected to it safe. Only problem is the new HW-OFF wire is visibly GY. I can put electric tap around and put a label. - Is my thinking correct?

I have not looked inside the junction box yet, also it's in the dark of the loft. So I don't know whether it is easily understandable or, not.

 

[Echo the husky]

NO, DON'T DO THAT. You will make the installation even more unsafe than it already is. You are not permitted to take any old wire from any old circuit, if someone alters or disconnects the circuit you have connected to the heating circuit could be left un-earthed. There are a few other resons why this is not a good idea as well.

You are unlikely to find a short length of suitable single core cable suitable for this alteration.

Please call an electrician to tidy up and correct your existing wiring. I expect there will be more problems in the other parts of the heating wiring as well.

 

[Echo the husky]

It looks like the cable gland is missing fom the pump as well.

 

[stardanny]

You can always move the programmer to a new location and nearest socket for that plug to go in then you can run 6 cores from programmer to junction box. Make it easier to run cable.

It all depend if hot water cylinder stat is wired in 3 cores not including G/Y wire.

Daniel.