Boiler not switching on, pump not running, no hot water - please help?

[stem]

Grey wire from 3 port goes to blue wire from cyl stat - no other wires exit from this part of the connector block, so the mysterious wire that 'should' go the terminal 1 isn't there.

Sounds about right.

The wiring centre looks untidy but is commensurate with many installations of that era. However, it would appear that the electrical connections look secure, the earth wires are sleeved, and there isn't any copper showing, so from an electrical point of view I wouldn't be worrying about it too much, believe me I have seen worse, much worse!

We have established that jumping L with T3 and T4 at the backing plate switches everything on and that by manipulating the room and cyl stat, the two channels switch on and off as expected.

Does this not tell us that fundamentally the basic components other than the timer are functional and given a hard wired (at the timer) 'all on' command, are working correctly.

Yes it does. It also means that the wires that are there do go to the right places.

I have a theory for you. I can't be sure, but it fits what is there, so here's what I suspect. Are you sitting comfortably? (showing my age now)..... Once upon a time, a system was installed with two, 2-port motorised valves. This type of installation doesn't require a connection to the programmer's terminal 1, so it wasn't installed. Later it was converted to have a 3-port valve. (often done at the time of a boiler replacement) Because the cylinder thermostat now needed an extra connection to the motorised valves grey wire, a slightly unusual T&E grey cable mentioned by @Harry Bloomfield, that was conveniently to hand was installed at the time. As it was far too much trouble to run an additional wire back to the programmer it wasn't done, and someone failed to set the programmer to its restricted settings (Gravity hot water / Pumped Central heating) which would have allowed the hot water to come on automatically when the heating was selected, thus allowing the motorised valve to get its live on the grey wire via the new wire from the cylinder thermostat..........After sometime, the systems present owner was informed about the missing wire and arranged to have it added, and they all lived happily ever after....The End

What next?

1) Replace the faulty programmer
2) Add the missing wire

 

[stem]

Ah!! I failed to notice this before. Suddenly all is clear.

the original timer I replaced in 2003/4 with the now failing Tempus Six was not two channel.

The problem with the missing wire is all your fault! You are the one who replaced a single channel programmer with a dual channel programmer and didn't add the wire to terminal 1 at the same time!!!!!

So, you've spoiled my story now, although I guess the part about not having the wire originally because it wasn't required is right. At least you can still have the happy ending.

 

[HazelFlorist]

@HazelFlorist given that you are reluctant to get someone in (for various reasons) and are keen to do this yourself, the best advice I can give you is to completely rewire the whole lot.

Flat cable twin & earth and triple & earth is not ideal but you're stuck with it.

Remove all the cables at the wiring centre and "Bell them out" using the buzzer on your mm to identify which cables go to other parts of the house, by joining 2 cores at the far end and mm across at the wiring centre.

Label those cables (not cores).

Get a new wiring centre that can be paired up with the most common diagrams (honeywell would be your best bet as these are referred to in most wiring diagrams). And it will have proper clamps for securing the cables as they enter. We call them "idiot boxes" so, a clue there .

Get a new programmer and cylinder stat, again stick with honeywell so everything is easier to reference.

Take your time and rewire everything... This way you will learn and understand the concept and process, rather than trying to decipher the existing concoction.

Use the 3 port as base as this is usually nearby and will always be consistent in colour coding.

You can use your immersion heater for hot water and its still warm enough to do without heating, whilst you work through this and get it completed.

That's my advice

I'll try to answe everyone's post individually so as not to ignore and or anything.

Thanks for your advice, I get where you are coming from.

A concern I have before starting again from scratch, and having looked at images online of the 'idiots box' is that some of the connections I don't have wires for - for example, it has connections for mains, and I don't believe I have mains as a direct supply in the airing cupboard - I think the mains supply from the system starts at the timer back plate, so if I understand correctly, I'm knackered straight away. Or have I misunderstood? I'm fairly confident that there is not a mains feed in the airing cupboard that doesn't arrive as part of another component's signal/feed/operation.

I also have the issue of the missing wire to T1 on the back plate and adding it would require major house surgery to plaster work, flooring etc to add it in (if the weird connected twin and earth cables at the back plate turn out not to be redundant and 'free to hijack' for T1 purposes).

So whilst a 'start from scratch' and learn as I go approach looks and sounds great, I fear I might not actually have the basic set up and cables where I need them to do so?

 

[HazelFlorist]

Sounds about right.

View attachment 170100

The wiring centre looks untidy but is commensurate with many installations of that era. However, it would appear that the electrical connections look secure, the earth wires are sleeved, and there isn't any copper showing, so from an electrical point of view I wouldn't be worrying about it too much, believe me I have seen worse, much worse!



Yes it does. It also means that the wires that are there do go to the right places.

I have a theory for you. I can't be sure, but it fits what is there, so here's what I suspect. Are you sitting comfortably? (showing my age now)..... Once upon a time, a system was installed with two, 2-port motorised valves. This type of installation doesn't require a connection to the programmer's terminal 1, so it wasn't installed. Later it was converted to have a 3-port valve. (often done at the time of a boiler replacement) Because the cylinder thermostat now needed an extra connection to the motorised valves grey wire, a slightly unusual T&E grey cable mentioned by @Harry Bloomfield, that was conveniently to hand was installed at the time. As it was far too much trouble to run an additional wire back to the programmer it wasn't done, and someone failed to set the programmer to its restricted settings (Gravity hot water / Pumped Central heating) which would have allowed the hot water to come on automatically when the heating was selected, thus allowing the motorised valve to get its live on the grey wire via the new wire from the cylinder thermostat..........After sometime, the systems present owner was informed about the missing wire and arranged to have it added, and they all lived happily ever after....The End



1) Replace the faulty programmer
2) Add the missing wire

I can't comment on the 2 port from new set up, but can confirm the boiler we replaced with our current one was the original one to the house, a Baxi Solo.
I can confirm that all the pipe work, cylinder and stat in the airing cupboard is original to the house which we moved into when only about 3 years old.
All I remember about the original timer was that when I fitted the replacement, I was pleased that I now had the functionality to have CH only.... except it never worked, so on reflection I am assuming it was only 1 channel.

1) Faulty timer on order and in the post.
2) Adding missing wire could be tricky as the timer and airing cupboard are almost at opposite corners of the house and getting a wire fitted behind the new kitchen units, kitchen tiles, plaster work, dot n dab and chipboard flooring trapped beneath the upstairs stud walls would be a nightmare. I really need to understand what the two joined up twin and earth cables are for at the rear of the back plate. I guess it would be too much to hope one of the cores was redundant and terminated in the airing cupboard. That would be too simple.

 

[stem]

My theory of the 2-port valves being changed for a 3-port was an attempt to come up with an explanation out why the wire from terminal 1 was missing, but you can discount that now. The reason it's missing is because you failed to make the swap from a single channel programmer to a dual channel programmer properly.

 

[HazelFlorist]

My theory of the 2-port valves being changed for a 3-port was an attempt to come up with an explanation out why the wire from terminal 1 was missing, but you can discount that now. The reason it's missing is because you failed to make the swap from a single channel programmer to a dual channel programmer properly.

I can appreciate that.

At the time, I was a home owner with a broken timer, who went to B&Q and asked for a suitable replacement. I bought the one suggested, attracted by the 'same back plate, fit in seconds' sales pitch and fitted it. I knew nothing of central heating systems at the time and all was well, beyond me noticing that I couldn't have CH only without HW command. I don't recall having that option previously, hence me believing on reflection I was single channel originally.

Only now trying to trace the fault 15 years later have I discovered that I'm missing a wire to enable full 2 channel control of what still appears to be a Y plan?

On further reflection and as confirmed by my bro-in-law who was round again last night, I don't have direct mains to the airing cupboard (unless I wire into the immersion feed) and unlikely have a free wire in place from the back plate to enable HW off command, therefore without tearing half the house apart to fit a wire behind, chipboard floor, tiled bathroom floor, tiled kitchen wall and new kitchen cupboards (where the timer is), this functionality is to remain unavailable. Not that CH only is a particularly essential feature.

In other news, the new timer arrived, is fitted and the system now works as it once did, albeit without CH only.

Thank you for the education.

 

[stem]

Glad you have it working.

If your new programmer has the optional facility to control 'pumped central heating system with gravity hot water' if you were to set the programmer to this setting (instead of 'fully pumped') the hot water will automatically come on at the times the central heating is set for and will save you the faff of having to make sure they are both set to the same 'on times'. You will still be able to have just the hot water on, on its own in the summer.

From what you have written above, this might actually what you originally had, especially as you didn't change the wiring when swapping programmers previously.

 

[DP]

Indeed - a hornet's nest of vipers I think is the term.

Difficult to know where to start.

Really?
Closer look seems to suggest what is there, seems to be standard Honeywell Sundial Y plan wiring schedule.

 

[ianmcd]

Really?
Closer look seems to suggest what is there, seems to be standard Honeywell Sundial Y plan wiring schedule.

over to you then @DP good luck my auld pal

 

[DP]

over to you then @DP good luck my auld pal

Not taking this curve ball Iain. My comment is as a spectator