Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is ON

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

But CH ON (brown)should be the same colour as Room stat 1 (Red)! Are they two separate cables joined together somewhere?

This is just a wire connecting the W/C CH On Terminal to the Programmer CH On Terminal.

But there should be wires from Boiler L and N to the boiler. You need to check at the boiler what is connected to the L, N and E terminals.

Shall check and confirm the Boiler connections.

The Stat is Drayton Digistat 1.

The Programmer is a Honeywell 6400C with 3 On/Off and 7 day setting.

These connections must have been wrong from when the System was installed by the Builders and all the people living in this house for the last 10 - 12 years simply lived it with :-( I wouldn't think anyone (plumber) who doesn't know what he is doing would ever tamper with the wirings !

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

This is just a wire connecting the W/C CH On Terminal to the Programmer CH On Terminal.

Of course they will be different colours; don't know what I was thinking of.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Have checked the boiler - it's a bit difficult to figure out what has come from where.
After removing the Front Left Side Cover, this is what I see :
There's a sort of Junction Box with seven points (this white junction box is screwed with 2 screws).
On the base it is marked as below

L N E Sw L N L E
PUMP MAINS

From one set of wires the connections are to the MAINS Terminals : Blue - N , Brown - L , Earth - E

From the 2nd set of wires the connections are to the PUMP Terminals : Blue - L , Blk - Not Connected , Brown - Switched Live (under Mains) , Earth - E

However, the diagram at the back side of the Front Panel says :

o o o o o o o
Earth No Contact Neutral No Contact Perm Live Sat Call Pump Live Out
(Blue) (Brown) (Red) (Yellow)

The white junction box could have been screwed / wired the other way round ( eg, the Earth is the Right most rather than the Left most)

Also, there is a another set of 4 junctions inside the Wall (covered by a plate) just by the side of the Mains Power switch of the Boiler (just below the Boiler).

Does this make any sense to you ?

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Sorry, the post was not very clear, so one more try :

L N E ................................................... Sw L N L E
PUMP .......................................................... MAINS

o ............. o .................. o ....................... o ................. o ............
Earth .... No Contact .... Neutral (Blue) ..... No Contact .... Perm Live (Brown)

........... o .......................... o
.... Sat Call (Red) ..... Pump Live Out (Yellow)

Also there is another sticker just above the 7 point terminal junction which says :

Programmer Wiring ....... CH OUT ....... DHW OUT ......... DHW OFF OUT

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

There's a sort of Junction Box with seven points (this white junction box is screwed with 2 screws).
On the base it is marked as below

L N E --- SwL N L E
PUMP----- MAINS

That's the connection block you use.

From one set of wires the connections are to the MAINS Terminals : Blue - N , Brown - L , Earth - E

What do the other end of these wires connect to? It should be the boiler terminals of the wiring centre.

From the 2nd set of wires the connections are to the PUMP Terminals : Blue - L , Blk - Not Connected , Brown - Switched Live (under Mains) , Earth - E

So the Blue is being used as a Live, which is not a good idea. The other end of the Blue wire should connect to the Boiler P/L terminal in the wiring centre.

The other end of the Brown wire should connect to the Boiler S/L terminal in the wiring centre.

The white junction box could have been screwed / wired the other way round ( eg, the Earth is the Right most rather than the Left most)

Very unlikely to be wired incorrectly. But if you want to check, the internal wire colours are:

Pump
L - Yellow
N - Blue (linked to Mains N)
E - Green/Yellow (linked to Mains E)
Mains
SwL - Red
N - Blue
L - Brown
E - Green/Yellow

There is a another set of 4 junctions inside the Wall

This is used when the optional programmer is mounted in the boiler.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

So, the Sw / L should be part of the Mains ?

What do the other end of these wires connect to? It should be the boiler terminals of the wiring centre.

Not sure, as the set of wires that connect to the Boiler Terminal in W/C have a Red (connected to P/L) and Yellow (connected to S/L). Also, I'm not sure if they are going / changing colours via any of those 4 junctions inside the wall (used for optional programmer).
Or are you talking of the other Set which is connected to the PUMP terminals of the Boiler (I thought that would go to the Boiler Terminal in the W/C (and not the set that connects to the MAINS)

So the Blue is being used as a Live, which is not a good idea. The other end of the Blue wire should connect to the Boiler P/L terminal in the wiring centre.

Does the Neutral here (PUMP terminal in the Boiler) not need to be connected ?
The S/L at the Boiler terminal in the W/C has a yellow wire ? Where is this coming from ? Also where is the Red wire connected to the P/L in the Boiler terminal of the W/C coming from ? The Blue from the Boiler PUMP terminal is not connected at the W/C end.

Pump
L - Yellow
N - Blue (linked to Mains N)
E - Green/Yellow (linked to Mains E)
Mains
SwL - Red
N - Blue
L - Brown
E - Green/Yellow

The wires going out of the other end of the Connection Block in the Boiler match these colours, although I've not checked where they are going inside the Boilers.

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

The diagram below should answer all your questions. I have given comments below.

So, the Sw / L should be part of the Mains?

It doesn't matter which cable the wire is in, as long as it connects to the right place!

the set of wires that connect to the Boiler Terminal in W/C have a Red (connected to P/L) and Yellow (connected to S/L).

See diagram for where they should connect at the boiler

Also, I'm not sure if they are going / changing colours via any of those 4 junctions inside the wall (used for optional programmer).

Don't understand. Which 4 junctions inside the wall?

Or are you talking of the other Set which is connected to the PUMP terminals of the Boiler (I thought that would go to the Boiler Terminal in the W/C (and not the set that connects to the MAINS)

I can see where you are getting confused, as was the installer. If you use the wiring centre the main supply connects to the the W/C Mains terminals. Everything else gets its mains supply from the wiring centre. So the boiler's "mains" comes from the L, N, E terminals of the W/C Boiler terminals. The same is true for the programmer and pump.

Is there a switch or fused spur on the wall near the boiler? Does this turn the power to the boiler on? Does it also turn the programmer on?

Is there also a switch/fused spur near the wiring centre? What does this turn on?

Does the Neutral here (PUMP terminal in the Boiler) not need to be connected?

No. This is because the pump is connected to the wiring centre and gets it neutral and earth connection there.

The S/L at the Boiler terminal in the W/C has a yellow wire ? Where is this coming from ? Also where is the Red wire connected to the P/L in the Boiler terminal of the W/C coming from ? The Blue from the Boiler PUMP terminal is not connected at the W/C end.

I can't even guess where these wires are coming from. Do you have a multimeter and know how to use it?

The wires going out of the other end of the Connection Block in the Boiler match these colours, although I've not checked where they are going inside the Boilers.

Then you can assume that the block is correctly wired.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Don't understand. Which 4 junctions inside the wall?

As I said earlier, there is another set of 4 junctions inside the Wall (covered by a plate) just by the side of the Mains Power switch of the Boiler (just below the Boiler). ------ which you said were for the optional Programmer mounting in the Boiler.

Is there a switch or fused spur on the wall near the boiler? Does this turn the power to the boiler on? Does it also turn the programmer on?

Yes there is a fused spur on the wall just below the boiler. This turns the Power ON / OFF for BOTH the Boiler and the Programmer.

Is there also a switch/fused spur near the wiring centre? What does this turn on?

No there in NONE. The Programmer / Wiring Centre Power is controlled from the fused spur on the wall just below the boiler.

So, with the above wiring in place, do the Links 1 & 6 still need cutting ?

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

As I said earlier, there is another set of 4 junctions inside the Wall (covered by a plate) just by the side of the Mains Power switch of the Boiler (just below the Boiler). ------ which you said were for the optional Programmer mounting in the Boiler.

Got you: my mistake, I was referring to the 4 terminals inside the boiler used for connecting the optional programmer. The blocks you found in the wall could be the connection to the spur and up to the wiring centre. They may explain the differing colours for e.g Switched Live (S/L and SwL) etc.

Yes there is a fused spur on the wall just below the boiler. This turns the Power ON / OFF for BOTH the Boiler and the Programmer.

No there in NONE. The Programmer / Wiring Centre Power is controlled from the fused spur on the wall just below the boiler.

How many wires are connected to the Boiler terminal block in the Wiring Centre

So, with the above wiring in place, do the Links 1 & 6 still need cutting ?

Yes.
You cut link 1 because you have a programmer.

If the pump is connected to the wiring centre, you cut link 6 because you have an overrun boiler.

If the pump is connected directly to the boiler, there is no need to cut link 6.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

How many wires are connected to the Boiler terminal block in the Wiring Centre

Just 3 :

S/L - Yellow - Should this be the Brown Wire from the SwL (Mains) Terminal of the Boiler ? ;

E - Earth ;

P/L - Red - Should this be the Blue Wire from the Live (Pump) Terminal of the Boiler ? ;

L - No Connection (always Live) - This must be getting it's Power from the Internal Wiring of the W/C - Should this be connected to the Brown Wire from the Live (Mains) Terminal of the Boiler ? ;

N - No Connection - Should this be connected to the Blue Wire from the Neutral (Mains) Terminal of the Boiler ? ;

So, am I correct in assuming that the Live Power comes from the Fused Spur (in the Wall below the Boiler) to the Live (Mains, not Pump) Terminal of the Boiler (via the Brown Wire from inside the Boiler) and then goes to the Live (Boiler) Terminal of the W/C ?
If so, where am I currently getting my Live on the Boiler Terminal of the W/C with no wires connected ?

Also, is the Live Input to the Wiring Centre (Red) Live coming directly from the Fused Spur in the Wall or should it come via the Terminal Block in the Boiler ?

Yes.
You cut link 1 because you have a programmer.

If the pump is connected to the wiring centre, you cut link 6 because you have an overrun boiler.

Is this irrespective of the wrong connections ? Or shall I correct the wiring first ?
What I am trying to find out is - will cutting Links 1 & 6 make it worse with the wrong connections or better ?

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

S/L - Yellow - Should this be the Brown Wire from the SwL (Mains) Terminal of the Boiler ?

Yes. They must join somewhere - possibly one of the terminal blocks in the wall

P/L - Red - Should this be the Blue Wire from the Live (Pump) Terminal of the Boiler?

Yes. Again they must join in a terminal block

L - No Connection (always Live) - This must be getting it's Power from the Internal Wiring of the W/C - Should this be connected to the Brown Wire from the Live (Mains) Terminal of the Boiler?

1. Yes it gets power internally
2. If the boiler is getting power directly from the fused spur there is no need to connect this terminal to the boiler mains L

N - No Connection - Should this be connected to the Blue Wire from the Neutral (Mains) Terminal of the Boiler?

See 2 above

E - Earth

Not sure why this is connected; the boiler should be earthed at the Fused Spur.
Can you find the other end and say what it is connected to?

Am I correct in assuming that the Live Power comes from the Fused Spur (in the Wall below the Boiler) to the Live (Mains, not Pump) Terminal of the Boiler (via the Brown Wire from inside the Boiler)

That's what appears to happen. If you have a meter you can verify this

and then goes to the Live (Boiler) Terminal of the W/C?

But you have said there is nothing connected to the Boiler L terminal in the W/C and there doesn't need to be

If so, where am I currently getting my Live on the Boiler Terminal of the W/C with no wires connected?

You answered this question yourself earlier. The W/C Boiler L, N and E terminals are fed by the internal wiring from the W/C Mains L, N and E terminals.

Is the Live Input to the Wiring Centre (Red) Live coming directly from the Fused Spur in the Wall or should it come via the Terminal Block in the Boiler?

It doesn't matter. It would appear to be coming from the fused spur. which is OK. There is no need to change it.

It would be a good idea to check out how the wires are linked together in the terminal blocks behind the wall.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Thanks doitmyself. Shall sort out the Wiring issues first.
Unfortunately I'd have to go on an overseas trip for about a month, so will probably leave it until the New Year.
Shall post an update once I am back.

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Shall post an update once I am back.

Please post update to this topic.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Sure .

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Sorry for not being able to get back to this for so long - got involved with so many things after returning back.
Are you still tracking it ? If so, we can check the Wirirng issues. Let me know so that I can post a short summary to avoid you trawling through it all again.

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

I hadn't been tracking this topic as I delete a subscription if there hasn't been any activity for a week; but I'm back on the case now.

Don't bother posting a summary - unless you think it would help you.

Check the wiring and post back.

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

The Wiring in the Boiler are as below.

(Sticker) Programmer Wiring ………........ CH OUT ....... DHW OUT ......... DHW OFF OUT (Sticker)

------- PUMP ------- ........................ ------------ MAINS ---------
... L ……….. N ……...…… E ------------ Sw L …... N …………. L …………. E
Top
Yellow ….. Blue …..... Yellow …............ Red ….. Blue …... Brown ….. Earth
.. o .......... o ............ o ................... o ........ o .......... o .......... o
.. 1 .......... 2 ............ 3 ................... 4 ........ 5 .......... 6 .......... 7
.. o .......... o ............ o ................... o ........ o .......... o .......... o
Bottom
. Blue …… Black …... Earth …............ Brown …. Blue …... Brown …… Earth
...... Not Connected

I have measured the A/C Voltages across the Terminals now.
They are :
Between 6 (Mains Live) & 5 (Mains Neutral) - 247 ~ V
Between 6 (Mains Live) & 7 (Mains Earth) - 247 ~ V
Between 6 (Mains Live) & 2 (Pump Neutral) - 247 ~ V
Between 6 (Mains Live) & 3 (Pump Earth ) - 247 ~ V
Between 6 (Mains Live) & 1 (Pump Live) - 247 ~ V When Boiler not Fired
Between 6 (Mains Live) & 1 (Pump Live) - 0 ~ V When Boiler Fired

Between 6 (Mains Live) & 4 (Switched Live) - 189 ~ V
(with Boiler NOT Fired & Multimeter Red on Terminal 6 )

Between 6 (Mains Live) & 4 (Switched Live) - 150 ~ V
(with Boiler NOT Fired & Multimeter Red on Terminal 4 )

Between 6 (Mains Live) & 4 (Switched Live) - 0 ~ V (with Boiler Fired)


D C Voltage
Between 6 (Mains Live) & 4 (Switched Live) - 12 V (with Boiler NOT Fired)
– Is it from the Pump ?
Between 6 (Mains Live) & 4 (Switched Live) - 0 V (with Boiler Fired)


The Wirings of the Room Stat are as below

0 …………… 0 …………..….. 0
1 ………….. 2 …………..….. 3
Red ….. No Contact ….. Yellow

The AC ~ Volts across the Room Stat Terminals are :
Between 1 (Red) and 3 (Yellow) - 247 ~ V (1[SUP]st[/SUP] thing in the morning)
The DC Volt is 0 V.

However, after the Programmer is ON once (Heating), the AC ~ Volt drops to 120 V between 1 (Red) and 3 (Yellow) with Multimeter Red on Terminal 1 (Red) and drops to 20 V between 1 (Red) and 3 (Yellow) with Multimeter Red on Terminal 3 (Yellow) ???
The DC Volt at that time is 50 V.
This is when I think the Boiler starts misbehaving.

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Thanks for the updated information.

The voltages are OK but there are a couple which may appear strange to you

Between 6 (Mains Live) & 4 (Switched Live) - 189 ~ V
(with Boiler NOT Fired & Multimeter Red on Terminal 6 )

Between 6 (Mains Live) & 4 (Switched Live) - 150 ~ V
(with Boiler NOT Fired & Multimeter Red on Terminal 4)

These are due to back-feed from the V4073A motorized valve. This contains a complicated arrangement of microswitches, resistors and a diode, which allows the valve to stop in mid-position.

D C Voltage
Between 6 (Mains Live) & 4 (Switched Live) - 12 V (with Boiler NOT Fired)

This will be from the motorised valve. The diode acts as a half-wave rectifier to the AC current and one of the resistors reduces the voltage.


Several post earlier I told you to cut Links 1, 4, 5 and 6 in the Honeywell wiring centre. Have you done this?

To make it quite clear, this is not me taking a stab in the dark, to see if it works. They are Honeywell's own instructions!

Link 1 is cut because you have a Programmer
Link 4 is cut because you have a mid-position valve
Link 5 is cut because you have a mid-position valve
Link 6 is cut because you have pump overrun.

There is no point going any further until you have cut these links!

 

[rojroj]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Links 4 & 5 are already cut, but not Links 1 & 6.
I haven't done this yet, as, on your post dated 19th Nov (Post # 20), you suggested to wait until we have checked the wirings :

1 and 6 will have to be cut, but not until we have sorted out my queries above!

It appears now that the connections to the Bolier are OK, isn't it ?

However, those of the Room Stat are NOT. On your same post :

The Red should only be live if the programmer has turned heating ON

This is not the case. Do you think that this could be due to Link 1 being intact ?

Also, from the same post :

Grey should not always be live.
Orange and White do not both have to be the same. The orange is switched live for the boiler, but White (and Grey) are control signals to the valve.

However, my previous notes were without a multimeter. Let me check with the Multimeter and post the readings.

 

[doitmyself]

Re: Boiler starts whenever the Room Stat calls for Heat - even when the Programmer is

Links 4 & 5 are already cut, but not Links 1 & 6.
I haven't done this yet, as, on your post dated 19th Nov (Post # 20), you suggested to wait until we have checked the wirings

Point taken!

However, thinking it through logically, cutting all four links will eliminate four possible causes of the problem. So, if the problem still occurs, we will know the cause cannot be in the wiring centre - it must be elsewhere.