Gloworm Boiler wiring

[tazcat]

Hi...This is my first post so....Hello
I have a Glow-worm Fuelsaver mk2 and have just purchased a wiring centre to tidy up the mess I currently have. This is the problem, the circuit board asks for live neutral and earth for the boiler, which is fine, but the boiler also has a yellow lead and I've no idea where that should go.
The wiring centre is a Drayton simp-l-fit and has the option for boiler over run. On the board it gives an extra 2 terminals within the boiler section ( s/l or p/l connection alongside L N and E).
Can anyone give me some idea where it should go ???
Thanks in advance
Rick

 

[Agile]

The yellow will probably be a call for heat which the existing wiring will make live when it wants the boiler on.

You can check this if you can measure voltage.

Tony

 

[chrishutt]

Does the Fuelsaver not have a pump overrun? If so, the pump will need to be fed by the outlet (sl?) on the boiler. Check the boiler manual for the wiring. There maybe a wiring diagram on the casing somewhere.

 

[tazcat]

Thank you for your prompt replies...
I can understand that the yellow from the boiler could be a call for heat, but there is no option on the wiring centre (unless it goes to the s/l on the boiler section). I have also tried to find the manual online but as yet cannot find one, so I don't know if it does actually have overrun.
On the current setup, it appears that this yellow from the boiler is linked into the cylinder thermo, but then how do i link it in when the new system has pre-wired plugs for the 3-way valve and cyl thermo.

Regards

Rick

 

[Agile]

"""I can understand that the yellow from the boiler could be a call for heat, but there is no option on the wiring centre (unless it goes to the s/l on the boiler section). """

Just suppose you thought of the yellow as going TO the boiler and not from it?

Chris, if there is a live/neutral connection to the boiler and only ONE other wire then it must be a call for heat connection to be made live by the controls.

A boiler with a pump over run will have TWO connections in addition to the live/neutral. One for call and one for pump.

Tony

 

[chrishutt]

First draw a diagram of your existing wiring and study it until you understand the entire control system. If you can't understand it, best not to go any further...

Have you tried Glow-worm web site for downloads?

 

[tazcat]

I have studied the wiring diagram on the casing and it does show boiler overrun, but I am wondering why I've only got the one extra wire when I should have 2 (s/l & p/l). What could happen if I connected the live. neutral and earth to the wiring centre and left the yellow disconnected ?

Rick

 

[ollski]

don't the fuelsavers have a pump overrun on the boiler stat?

 

[chrishutt]

Perhaps p/l means pump live. Then you have the main permanent live connection, a switched live from the controls and a pump live back to the pump to provide overrun. Makes sense?

It's quite likely that the existing wiring was wrong and lacked the pump overrun connection, or even the permanent live! That's why you need to make a diagram and follow through all the connections.

 

[tazcat]

Hello again.... things are looking a little clearer now, the fuelsaver DOES have overrun and I have 5 not 4 cables running from it (red blue black grn/ylw and yellow) now I just have to work out what goes where.
Are these wire colours industry standard

Rick

 

[chrishutt]

Don't rely on the wiring colours. Green/yellow may even be a switched live!

 

[tazcat]

Here we go...


Yellow- cylinder stat

Green/Yellow- Earth

Blue- Neutral

Black- Live (linked to central heating pump)

Red- Live (from timer/programmer)


Any ideas how that translates to L E N S/L P/L (i know E is earth)

Cheers

Rick

 

[chrishutt]

You haven't followed through the rest of the wiring and controls. Nor have you told us what sort of controls you have - motorised valves, etc.

 

[tazcat]

My existing setup is a mish mash of connector blocks so thats why I bought a wiring centre.
The new pack is a Drayton Sim-p-l Fit, It consists of a Tempus 7 programmer, wiring centre, pre-wired cyl stat, pre-wired drayton 3 way motorised valve and a room stat.
The motorised valve and the cy stat have plugs to enable easier connection and everything else is straight forward.
It all fits into place nicely except for the boiler (which I'm sure will in the end).
So, what exactly does s/l and p/l mean.
Once I know what these 2 connections do, it will be easy to test which are live all the time and which ones are switched.
Would I be right in assuming the black which is linked into the central heating pump live, and the yellow which is linked into the cyl-stat would eventually be the p/l and the s/l connections.

 

[Agile]

You seem to be getting very confused by something that seems very simple to us. One of your initial problems was that you did not initially admit to having five wires to/from your boiler.

I feel we have already told you:-

s/l Switched live from controls to call for heat from boiler.

p/l Live from the boiler to operate the pump.

Tony