Are condensing boiler control terminals different from combi,s?

[hertzal]

In the days of wiring combi,s,I remember there was always a link to remove to wire in the clock and/or room stat using voltage free connections.I recently wired a greenstar Ri regular on a y plan & the switched live from the valve simply went to terminal LR on the boiler,no sign of any removable links,so is this common on this type of boiler,or does it depend on manufacturer?

Ps,A builder had tried to wire boiler before myself & may have tampered with connections. Regards,HZ

 

[batty]

Most boilers i have fitted be it combi or condensing have a link generally heating controls are wired through boiler. You really need to read installation instructions it can be very expensive for you if you blow printed circuit board up.

 

[Andy™]

In the days of wiring combi,s,I remember there was always a link to remove to wire in the clock and/or room stat using voltage free connections.I recently wired a greenstar Ri regular on a y plan & the switched live from the valve simply went to terminal LR on the boiler,no sign of any removable links,so is this common on this type of boiler,or does it depend on manufacturer?Ps,A builder had tried to wire boiler before myself & may have tampered with connections. Regards,HZ

depends on boiler. reading the manual is the only way to find out

 

[NozSpark]

I know that the Worcester junior Si has a little metal link between LS and LR,,, don't know about the Ri though

 

[PC Electrics]

As with most things of this sort, it varies from make to make and model to model.

The most important thing here is TO READ THE INSTALLATION INSTRUCTIONS that come with any new boiler. There will be a section on electrical connections. Getting it wrong could land you buying a new PCB for a new boiler. And the plumber concerned is unlikley to ever call you again!!

 

[Goldspark]

Hi Hertzal

I agree that connecting boilers and central heating systems can be confusing.

You may find this link to some explainations and diagrams useful:

Central Heating Boiler Electrical Wiring Connection Diagrams for Electricians | Electrician's Blog

 

[mikep]

Yep I only like fitting Worcester Bosch boilers, like to use the Horstman programable thermostat. only needs 2 wires connected to LS + LR nice and simple think TLC do the programmer for

 

[steptoe]

heating systems are EASY,

if you can read, do dot to dot, and tell the difference between volt free and voltage switched then there really is no black art,

the one thing you need to do is learn why it is actually connected the way it is,

remember, stats and programmers are only switches, understand how a switch works and you will be able to design and wire your own bespoke systems,

this is maybe why I get called to so many of these that arent simple plan systems like in the leaflets,

last week had a supposed Y plan, plumber had it piped wrong and spark had no idea,

4 2port valves and a 3port valve for 3 zones, with 2 valves fighting each other and 2 more doing the same thing! :C

 

[batty]

You won't say its easy when you get older Steps your eyes go and you haven't got your specs with you to read the plans although i suppose you should do it from memory after a while.

 

[sellers]

Does it not depend if its a combi or not? Combi consiting of LNE supply and optional external stat, hense the link (optional)

conventional boiler, consisting of switched live neutral and earth, and in the case of newer boilers permanent live for pump over-run. So switched live becomes live return and new perm live run in. No need for link as the boiler wouldnt work properly with it in.

 

[steptoe]

ah sellers, but only if the boiler is 230v switched, some boilers have ELV switching, this is when PCBs go BANG!

 

[Doc Hudson]

As with most things of this sort, it varies from make to make and model to model.The most important thing here is TO READ THE INSTALLATION INSTRUCTIONS that come with any new boiler. There will be a section on electrical connections. Getting it wrong could land you buying a new PCB for a new boiler. And the plumber concerned is unlikley to ever call you again!!

In the days of wiring combi,s,I remember there was always a link to remove to wire in the clock and/or room stat using voltage free connections.I recently wired a greenstar Ri regular on a y plan & the switched live from the valve simply went to terminal LR on the boiler,no sign of any removable links,so is this common on this type of boiler,or does it depend on manufacturer?Ps,A builder had tried to wire boiler before myself & may have tampered with connections. Regards,HZ

A lot of manufactures have websites often with links to copies of installation manuals, Probably best to have a google for a copy of the manual if you haven't got one, because as PCelectrics says connections do change over time with make and model.

Doc H,

 

[sellers]

ah sellers, but only if the boiler is 230v switched, some boilers have ELV switching, this is when PCBs go BANG!

Isn't that only the case with Combi's? as conventional boilers use 240v external wiring for pumps, valves, programmers etc.