New system boiler problem

[oldBiker]

I have recently fitted a Main system 28 HE boiler, to replace my ageing standard b/f boiler. I removed the old ch pump and wiring, as the new boiler has its own pump. I have a Drayton 3 way valve for CH/HW/both, which was new about two years ago.
When the CH is on it is fine...brilliant in fact. When HW comes on or is switched on, the pump stays on (run by the permanent live) but the voltage at the boiler is reduced to 50volts for some reason. When on CH the voltage is 240v. I have changed nothing else apart from removing the frost stat at old boiler and using the perm live for the pump overrun. The programmer is an ACL Lifestyle (Appliance Components Ltd, taken over by Drayton). I also have an ACL thermostat, circa 20years old. There is also a thermostat control to the HW boiler.
Can anyone please advise why I am only receiving 50v when on HW.

 

[D_Hailsham]

When the CH is on it is fine...brilliant in fact. When HW comes on or is switched on, the pump stays on (run by the permanent live) but the voltage at the boiler is reduced to 50volts for some reason. When on CH the voltage is 240v. I have changed nothing else apart from removing the frost stat at old boiler and using the perm live for the pump overrun.There is also a thermostat control to the HW boiler.
Can anyone please advise why I am only receiving 50v when on HW.

Valve installed incorrectly or wiring fault.
HW Boiler Thermostat: Do you mean a thermostat strapped to the side of the hot water cylinder in the airing cupboard?

Valve
The port labelled A should connect to the radiators
The port labelled B should connect to the hot water cylinder
The port labelled AB should be connect to the boiler

Wiring
Here is the standard wiring diagram

Ignore the pump connections.
The boiler L should go to terminal 1 not terminal 8 (see below)
Terminal 8 should connect to boiler terminal 5 (1=L, 2=N). Remove any link between 4 and 5.

View media item 70
Don't understand what you mean by the pump overrun. This boiler requires a permanent three wire (LNE) connection. There are two ways of doing this:
1. Connect the boiler to a fused spur and then supply the wiring centre from the boiler's L,N,E terminals.
2. Connect the wiring centre to the fused spur and feed the boiler from the wiring centre's LNE terminals.

It all depends on the location of the fused spur. You should not feed the boiler and wiring centre from two separate sources as it could be dangerous.

 

[Agile]

Was it working and has failed?

Or is this your own installation and has never worked?

The pump is normally powered from the boiler so that it does not run all the time.

You trace electrical faults by following the supply back and testing further back.

Tony

 

[oldBiker]

Thanks for that.
I was under the impression that the permanent live, not the switched live went to terminal 2 on the boiler, and that this wire would be the original live cable for the (Now removed ) frost stat at the old boiler.
There has been no change with the piping ports.
I can put a fused spur supply from the GF ring to the boiler (LN & E), but what will trigger the boiler to fire up from the programmer.... is it just the 230v switched live cable coming from the control centre/programmer?.
I work away from home, and will not be able to do any work on this until the coming weekend, however it is safe, as I have switched off the HW section at the programmer. The CH section is still running on the timed section.
Await your comments.........

When the CH is on it is fine...brilliant in fact. When HW comes on or is switched on, the pump stays on (run by the permanent live) but the voltage at the boiler is reduced to 50volts for some reason. When on CH the voltage is 240v. I have changed nothing else apart from removing the frost stat at old boiler and using the perm live for the pump overrun.There is also a thermostat control to the HW boiler.
Can anyone please advise why I am only receiving 50v when on HW.

Valve installed incorrectly or wiring fault.
HW Boiler Thermostat: Do you mean a thermostat strapped to the side of the hot water cylinder in the airing cupboard?

Valve
The port labelled A should connect to the radiators
The port labelled B should connect to the hot water cylinder
The port labelled AB should be connect to the boiler

Wiring
Here is the standard wiring diagram

Ignore the pump connections.
The boiler L should go to terminal 1 not terminal 8 (see below)
Terminal 8 should connect to boiler terminal 5 (1=L, 2=N). Remove any link between 4 and 5.

View media item 70
Don't understand what you mean by the pump overrun. This boiler requires a permanent three wire (LNE) connection. There are two ways of doing this:
1. Connect the boiler to a fused spur and then supply the wiring centre from the boiler's L,N,E terminals.
2. Connect the wiring centre to the fused spur and feed the boiler from the wiring centre's LNE terminals.

It all depends on the location of the fused spur. You should not feed the boiler and wiring centre from two separate sources as it could be dangerous.

 

[oldBiker]

Tony,
The original boiler was 50k btu, and I replaced it with a much larger boiler due to recent extensions on my house.
Yes the new pump is part of the boiler.
My current power supply is at the programmer in the kitchen.
The boiler is about twenty feet away in the back of the garage, but I can easily put a fused spur supply there.
Regards.

Was it working and has failed?

Or is this your own installation and has never worked?

The pump is normally powered from the boiler so that it does not run all the time.

You trace electrical faults by following the supply back and testing further back.

Tony

 

[D_Hailsham]

I was under the impression that the permanent live, not the switched live went to terminal 2 on the boiler, and that this wire would be the original live cable for the (Now removed ) frost stat at the old boiler.

I suppose it depends on which start numbering the terminals. Starting from the Fuse end:
1 = Permanent Live from switched spur or wiring centre L terminal
2 = Neutral from spur or wiring centre
3 = Earth from spur or wiring centre
4 = 230v supply to external controls, e.g thermostat (this is not required as the external controls are fed from the wiring centre)
5 = Switched Live to boiler

I can put a fused spur supply from the GF ring to the boiler (LN & E), but what will trigger the boiler to fire up from the programmer.... is it just the 230v switched live cable coming from the control centre/programmer?.

Yes. The switched live from terminal 8 in thr wiring centre will fire the boiler.

You can put the fused spur either at the boiler end or at the wiring centre end; it does not matter which.

If you put it at the boiler end, run a four core cable (brown, blue, green/yellow, other colour) from the boiler to the wiring centre. At boiler end connect to terminals 1,2 3 (usual colours) and 5 (other colour). At the boiler end connect the standard colours to terminals 1, 2 and 3 (see standard wiring diagram posted earlier) connect the fourth wire to terminal 8 in the wiring centre.

If you put the fused spur at the wiring centre end, just run the four core cable down to the boiler, wired as above.

You should use heat resistant cable. B&Q sell it "Tower" brand.

 

[oldBiker]

Mr Hailsham, thanks for your help so far......
1 to 5 is exactly as you described at my boiler, and as I have wired it.
From what you have said, I need to connect a four core cable between the wiring centre (not the programmer) and the boiler. Currently the fused spur feed is at the programmer which is about 15ft away from the wiring centre (and not easy to put new cable in to connect between). I can with difficulty connect a new cable between the wiring centre and the boiler (a distance of about forty feet, yes I do have a big detached house). So is it possible to retain my live feed as it is, (at programmer) and connect a new 4c cable between Wiring Centre and boiler? The cable, does it only need to be heat resistant at the boiler end for the last metre or so, as I have a reel of 4c x 1,5 cable available at home.

I was under the impression that the permanent live, not the switched live went to terminal 2 on the boiler, and that this wire would be the original live cable for the (Now removed ) frost stat at the old boiler.

I suppose it depends on which start numbering the terminals. Starting from the Fuse end:
1 = Permanent Live from switched spur or wiring centre L terminal
2 = Neutral from spur or wiring centre
3 = Earth from spur or wiring centre
4 = 230v supply to external controls, e.g thermostat (this is not required as the external controls are fed from the wiring centre)
5 = Switched Live to boiler

I can put a fused spur supply from the GF ring to the boiler (LN & E), but what will trigger the boiler to fire up from the programmer.... is it just the 230v switched live cable coming from the control centre/programmer?.

Yes. The switched live from terminal 8 in thr wiring centre will fire the boiler.

You can put the fused spur either at the boiler end or at the wiring centre end; it does not matter which.

If you put it at the boiler end, run a four core cable (brown, blue, green/yellow, other colour) from the boiler to the wiring centre. At boiler end connect to terminals 1,2 3 (usual colours) and 5 (other colour). At the boiler end connect the standard colours to terminals 1, 2 and 3 (see standard wiring diagram posted earlier) connect the fourth wire to terminal 8 in the wiring centre.

If you put the fused spur at the wiring centre end, just run the four core cable down to the boiler, wired as above.

You should use heat resistant cable. B&Q sell it "Tower" brand.

 

[D_Hailsham]

1 to 5 is exactly as you described at my boiler, and as I have wired it.
From what you have said, I need to connect a four core cable between the wiring centre (not the programmer) and the boiler. Currently the fused spur feed is at the programmer which is about 15ft away from the wiring centre (and not easy to put new cable in to connect between). I can with difficulty connect a new cable between the wiring centre and the boiler (a distance of about forty feet, yes I do have a big detached house). So is it possible to retain my live feed as it is, (at programmer) and connect a new 4c cable between Wiring Centre and boiler? The cable, does it only need to be heat resistant at the boiler end for the last metre or so, as I have a reel of 4c x 1,5 cable available at home.

I am trying to picture your wiring Correct me if I am wrong.

The fused spur feeds the programmer
There is a 3 core cable from programmer L. N and E terminals to the boiler L, N and E terminals
There are Neutral and Earth connections from the programmer to the wiring centre

WIRING CENTRE

Room Stat
1 wire connected to programmer CH On
1 wire connected to Neutral
1 wire connected to valve White wire

Cylinder Stat
One wire connected to programmer HW ON
One wire connected to programmer HW OFF and valve Grey wire
One wire connected to valve Orange and Boiler terminal 5

40 feet is a long way to run a cable and it's only the bit which enters the boiler which has to be heat resistant.

Info about the room and cylinder stats might be needed, i.e . make and model and terminal numbers/names.

 

[oldBiker]

Just to clarify further.........
The fused spur feeds the programmer in the kitchen.
There is a thermostat in the hall. (presumably connected to the conn block
There is a 3 port valve in the airing cupboard, connected to conn block.
There is an 8 way connector block in the airing cupboard.
There is a cylinder stat on the side of the HW boiler, with cable to conn block.
Thermostat (room) is ACL circa 20 years old.
Programmer is ACL Lifestyle circa 20 years old.
In future I intend replacing these when I have resolved this boiler problem.
3 port valve is Drayton (previously ACL)
The new boiler is located in a room at back of garage, and now has circulating water pump integral with boiler.
The new boiler feeds 23 radiators.
Unfortunately I work away from home, and I have not yet worked out which wires fully connect to where. This isn't a problem, as I can soon trace these when I am back home.
I am presuming the 'Live' cable that fed the original frost stat at the original boiler was fed from the programmer, as it is one of the four cable cores that come from the programmer to feed the boiler. It is this 'live cable I have used for the live to the boiler. The switched live is one of the other cores of the four that feeds into terminal 2 of the boiler. In line with the manufacturers instructions, I removed the link at the boiler conn block between terminals 1 and 2.
Hope this helps you to understand my system a little more.......
Apologies for being such a pain!!!!
Oh and thanks again.

1 to 5 is exactly as you described at my boiler, and as I have wired it.
From what you have said, I need to connect a four core cable between the wiring centre (not the programmer) and the boiler. Currently the fused spur feed is at the programmer which is about 15ft away from the wiring centre (and not easy to put new cable in to connect between). I can with difficulty connect a new cable between the wiring centre and the boiler (a distance of about forty feet, yes I do have a big detached house). So is it possible to retain my live feed as it is, (at programmer) and connect a new 4c cable between Wiring Centre and boiler? The cable, does it only need to be heat resistant at the boiler end for the last metre or so, as I have a reel of 4c x 1,5 cable available at home.

I am trying to picture your wiring Correct me if I am wrong.

The fused spur feeds the programmer
There is a 3 core cable from programmer L. N and E terminals to the boiler L, N and E terminals
There are Neutral and Earth connections from the programmer to the wiring centre

WIRING CENTRE

Room Stat
1 wire connected to programmer CH On
1 wire connected to Neutral
1 wire connected to valve White wire

Cylinder Stat
One wire connected to programmer HW ON
One wire connected to programmer HW OFF and valve Grey wire
One wire connected to valve Orange and Boiler terminal 5

40 feet is a long way to run a cable and it's only the bit which enters the boiler which has to be heat resistant.

Info about the room and cylinder stats might be needed, i.e . make and model and terminal numbers/names.

 

[D_Hailsham]

In case you did not know, when you reply you should normally use the "post reply" button - bottom left below the last post on each page. The "quote" button is used if you want to quote all or part of a post in your reply.

Thermostat (room) is ACL circa 20 years old.
Programmer is ACL Lifestyle circa 20 years old.
In future I intend replacing these when I have resolved this boiler problem.

Of course the problem may be due to one of these thermostats.

Unfortunately I work away from home, and I have not yet worked out which wires fully connect to where. This isn't a problem, as I can soon trace these when I am back home.

If you could trace the wires and post a list or diagram, it would be very helpful. Diagnosing faults over the internet is bad enough, but it's even worse when you don't have the full information.

I am presuming the 'Live' cable that fed the original frost stat at the original boiler was fed from the programmer, as it is one of the four cable cores that come from the programmer to feed the boiler. It is this 'live cable I have used for the live to the boiler. The switched live is one of the other cores of the four that feeds into terminal 2 of the boiler. In line with the manufacturers instructions, I removed the link at the boiler conn block between terminals 1 and 2.

This is the most important bit of info you have given in your last post.

To clarify. You have four cores between the programmer.
1 Programmer Live to Boiler Live
2 Programmer Neutral to Boiler Neutral
3 Programmer Earth to Boiler Earth
4 Programmer ? to Boiler terminal 2.

Cores 1, 2 and 3 are correct. It's core 4 which is wrong.

Which terminal do you call terminal 2? The end one or the one next to it?

Do you also have a core from the connection block to the boiler terminal 1? It will be connected to the same terminal as the orange wire from the valve and a core from the HW cylinder thermostat.

I suggest you wait until you are back home and can check everything.

 

[oldBiker]

Thanks for that. As it is the first time I have used the site, I wasn't sure which box to tick!!!
Anyway, as you suggested, the 4th cable may be incorrectly connected somewhere.
Until I identify clearly which cables go to where, I don't think we will be able to resolve this problem.....
However, connection block on the boiler....from bottom...terminal 1 is 230v S/L from external control; terminal 2 is left empty (with link removed); terminal 3 is earth; terminal 4 is Neutral (blue); terminal 4 is Live (brown) which has a fast blow 2A fuse across;
Not sure if I have a connection from terminal 1 at boiler to conn block, as this may be via the controller....again can only confirm when I check on Friday when back home.
The 3 port valve is opening (or going mid position if CH is on) to allow water to flow to the HW boiler when the programmer requests this, as seen by the positioner on the side of the actuator, but as stated before, the boiler does not fire up, and cuts out if the CH is on.
To make life easier would it be possible to fit wireless pieces of kit to facilitate any hard wiring? I may be prepared to purchase the necessary items if possible.
Again, thanks for your efforts..........
OldBiker
PS: I am an old biker because I ride a 1400cc Suzuki flying machine, and I am over 60.

 

[Agile]

OldBiker

PS: I am an old biker because I ride a 1400cc Suzuki flying machine, and I am over 60.

I know a couple of friends, both ex-policemen, who look about 70 but they both still enjoy their bikes.

They went to India about four years ago and bought new bikes, rode them round for 4000 miles and afterwards had them shipped back to the UK.

Next time they went to India they both got a VERY bad stomach and had to come back early. One of them has been going to India 3-5 times a year for about 10 years so it must have been something very special.

Hailsham has to time to explain what you need to do to check your system wiring. Now its down to you!

Tony

 

[oldBiker]

Yes I love my biking, and normally go out with about 6-8 mates. We either go into N Wales or N Yorkshire. My bike does 0-60 in 2.6 secs and 0-100 in 6.7 secs.....I love it and have been biking for almost 50 years!!!!!
Like your friends, biking becomes a disease you cannot get rid of!!!!!
Unfortunately my wife is not into biking.
My hobby is building, and has been for the last 35 years. I am a mechanical based engineer, (ex construction manager up to £30m multi builds) but I do all building trades. I have just built a six room extension on my house. There is only the wife and I that live there. It is a bit more difficult working 4 days a week away from home to get the work done, but apart from the above I don't socialize, doesn't interest me.
I will be in contact on Friday when I have further information.........
For now, thanks again for your help.

 

[D_Hailsham]

Thanks for that. As it is the first time I have used the site, I wasn't sure which box to tick!!!

We all learn eventually

Until I identify clearly which cables go to where, I don't think we will be able to resolve this problem

Couldn't agree more.

However, connection block on the boiler....from bottom...terminal 1 is 230v S/L from external control; terminal 2 is left empty (with link removed); terminal 3 is earth; terminal 4 is Neutral (blue); terminal 4 is Live (brown) which has a fast blow 2A fuse across;

I was numbering the terminals from the other end. So your 1 is my 5 - that's the correct terminal to use.

Not sure if I have a connection from terminal 1 at boiler to conn block, as this may be via the controller....again can only confirm when I check on Friday when back home.

By controller, I assume you mean the programmer. It should go direct to the conn block. Same terminal as valve orange and a wire from cylinder stat.

The 3 port valve is opening (or going mid position if CH is on) to allow water to flow to the HW boiler when the programmer requests this, as seen by the positioner on the side of the actuator, but as stated before, the boiler does not fire up, and cuts out if the CH is on.

At the risk of repeating myself, it's called a hot water cylinder.

To make life easier would it be possible to fit wireless pieces of kit to facilitate any hard wiring? I may be prepared to purchase the necessary items if possible.

You need to sort out the problem before thinking of wireless. In any case, the wireless connection only works between the thermostat in the hall, or wherever, and the conn block in the airing cupboard. You will still neeed the programmer to control HW times and a cable between conn block and boiler.

 

[oldBiker]

Prior to evaluating the destinations of the cables, I took volatages as follows............
1. Programmer ON via fused spur, but each output as OFF: L=240volts and S/L =0 volts.
2 Programmer HW only: L=240 volts and S/L =0 volts
3 Programmer CH only: L= 240 volts and S/l =240 volts
4 Programmer HW and CH: L = 240 volts and S/L =50 volts

I have now done a survey on the wiring at each item, and the results are as follows.....
Boiler referred to as 'B'
Programmer referred to as 'P'
3 port valve referred to as 'V'
Thermostat referred to as 'S'
Terminal block referred to as 'TB'
Cylinder thermostat referred to as 'CT'
I have left out the earths

A) Boiler (B)
1...Permanent live to P (live)
2...Switched live to TB1 (via the P)
3...Neutral to P (N)

B)...Programmer (P)
N...to B3 and TB2
L...to B1
2...nothing
3...to TB3
4...to TB5

C)...Thermostat (S)
1...to TB5
2...to TB4
3...to Earth
4...to TB6

D)...3 Port valve (V)
1...(blue)...TB6
2...(white)...TB4
3...(black)...TB2
4...(red)...TB1

Terminal Block (TB)
1...to B2/V4/CT3
2...to P1/P(N)/V3/CT2
3...to P3/CT1
4...to S2/V2
5...to P4/S1
6...to V1/S4
7...nothing
8...earth

Cylinder thermostat (CT)
1...red to TB3
2...yellow to TB2
3...black to TB1

I have a spare cable running from the Programmer to the Terminal block.
I ahve a spare cable running from the Programmer to the boiler.
I hope you can identify from this information what the problem is.
Regards,
old Biker